CODES

ADOPTS WITH AMENDMENTS:

International Energy Conservation Code 2018 (IECC 2018)

Chapter 1 [CE] Scope and Administration

Chapter 2 [CE] Definitions

Chapter 3 [CE] General Requirements

Chapter 4 [CE] Commercial Energy Efficiency

Chapter 5 [CE] Existing Buildings

Chapter 6 [CE] Referenced Standards

Appendix CA Solar-Ready Zone—commercial

Chapter 1 [RE] Scope and Administration

Chapter 2 [RE] Definitions

Chapter 3 [RE] General Requirements

Chapter 4 [RE] Residential Energy Efficiency

Chapter 5 [RE] Existing Buildings

Chapter 6 [RE] Referenced Standards

Appendix RA Solar-Ready Provisions—detached One- And Two-Family Dwellings and Townhouses

The provisions in this chapter are applicable to commercial buildings and their building sites.

Commercial buildings shall comply with one of the following:

  1. The requirements of ANSI/ASHRAE/IESNA 90.1.
  2. The requirements of Sections C402 through C405 and C408. In addition, commercial buildings shall comply with Section C406 and tenant spaces shall comply with Section C406.1.1.
  3. The requirements of Sections C402.5, C403.2, C403.3 through C403.3.2, C403.4 through C403.4.2.3, C403.5.5, C403.7, C403.8.1 through C403.8.4, C403.10.1 through C403.10.3, C403.11, C403.12, C404, C405, C407 and C408. The building energy cost shall be equal to or less than 85 percent of the standard reference design building.

Where some or all of an existing fenestration unit is replaced with a new fenestration product, including sash and glazing, the replacement fenestration unit shall meet the applicable requirements for U-factor and SHGC in Table C402.4.

Exception: An area-weighted average of the U-factor of replacement fenestration products being installed in the building for each fenestration product category listed in Table C402.4 shall be permitted to satisfy the U-factor requirements for each fenestration product category listed in Table C402.4. Individual fenestration products from different product categories listed in Table C402.4 shall not be combined in calculating the area-weighted average U-factor.

Building thermal envelope assemblies for buildings that are intended to comply with the code on a prescriptive basis in accordance with the compliance path described in Item 2 of Section C401.2, shall comply with the following:

  1. The opaque portions of the building thermal envelope shall comply with the specific insulation requirements of Section C402.2 and the thermal requirements of either the R-value-based method of Section C402.1.3; the U-, C- and F-factor-based method of Section C402.1.4; or the component performance alternative of Section C402.1.5.
  2. Roof solar reflectance and thermal emittance shall comply with Section C402.3.
  3. Fenestration in building envelope assemblies shall comply with Section C402.4.
  4. Air leakage of building envelope assemblies shall comply with Section C402.5.

Alternatively, where buildings have a vertical fenestration area or skylight area exceeding that allowed in Section C402.4, the building and building thermal envelope shall comply with Section C401.2, Item 1 or Section C401.2, Item 3.

Walk-in coolers, walk-in freezers, refrigerated warehouse coolers and refrigerated warehouse freezers shall comply with Section C403.10.1 or C403.10.2.

The following low-energy buildings, or portions thereof separated from the remainder of the building by building thermal envelope assemblies complying with this section, shall be exempt from the building thermal envelope provisions of Section C402.

  1. Those with a peak design rate of energy usage less than 3.4 Btu/h • ft2 (10.7 W/m2) or 1.0 watt per square foot (10.7 W/m2) of floor area for space conditioning purposes.
  2. Those that do not contain conditioned space.
  3. Greenhouses.

Buildings that comply with the following shall be exempt from the building thermal envelope provisions of this code:

  1. Are separate buildings with floor area not more than 500 square feet (50 m2).
  2. Are intended to house electronic equipment with installed equipment power totaling not less than 7 watts per square foot (75 W/m2) and not intended for human occupancy.
  3. Have a heating system capacity not greater than (17,000 Btu/hr) (5 kW) and a heating thermostat setpoint that is restricted to not more than 50°F (10°C).
  4. Have an average wall and roof U-factor less than 0.200 in Climate Zones 1 through 5 and less than 0.120 in Climate Zones 6 through 8.
  5. Comply with the roof solar reflectance and thermal emittance provisions for Climate Zone 1.

Building thermal envelope opaque assemblies shall comply with the requirements of Sections C402.2 and C402.4 based on the climate zone specified in Chapter 3. For opaque portions of the building thermal envelope intended to comply on an insulation component R-value basis, the R-values for insulation shall be not less than that specified in Table C402.1.3. Commercial buildings or portions of commercial buildings enclosing Group R occupancies shall use the R-values from the “Group R” column of Table C402.1.3. Commercial buildings or portions of commercial buildings enclosing occupancies other than Group R shall use the R-values from the “All other” column of Table C402.1.3.

TABLE C402.1.3

OPAQUE THERMAL ENVELOPE INSULATION COMPONENT MINIMUM REQUIREMENTS, R-VALUE METHODa, i

CLIMATE ZONE1234 EXCEPT MARINE5 AND MARINE 4678
All otherGroup RAll otherGroup RAll otherGroup RAll otherGroup RAll otherGroup RAll otherGroup RAll otherGroup RAll otherGroup R
Roofs
Insulation entirely
above roof deck
R-20ciR-25ciR-25ciR-25ciR-25ciR-25ciR-30ciR-30ciR-30ciR-30ciR-30ciR-30ciR-35ciR-35ciR-35ciR-35ci
Metal buildingsbR-19 +
R-11 LS
R-19 +
R-11 LS
R-19 +
R11 LS
R-19 +
R-11 LS
R-19 +
R-11 LS
R-19 +
R-11 LS
R-19 +
R-11 LS
R-19 +
R-11 LS
R-19 +
R-11 LS
R-19 +
R-11 LS
R-25 +
R-11 LS
R-25 +
R-11 LS
R-30 +
R-11 LS
R-30 +
R-11 LS
R-30 +
R-11 LS
R-30 +
R-11 LS
Attic and otherR-38R-38R-38R-38R-38R-38R-38R-38R-38R-49R-49R-49R-49R-49R-49R-49
Walls, above grade
MassgR-5.7cicR-5.7cicR-5.7cicR-7.6ciR-7.6ciR-9.5ciR-9.5ciR-11.4ciR-11.4ciR-13.3ciR-13.3ciR-15.2ciR-15.2ciR-15.2ciR-25ciR-25ci
Metal buildingR-13+
R-6.5ci
R-13 +
R-6.5ci
R13 +
R-6.5ci
R-13 +
R-13ci
R-13 +
R-6.5ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13 +
R-13ci
R-13+
R-19.5ci
R-13 +
R-13ci
R-13+
R-19.5ci
Metal framedR-13 +
R-5ci
R-13 +
R-5ci
R-13 +
R-5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-7.5ci
R-13 +
R-15.6ci
R-13 +
R-7.5ci
R-13+
R17.5ci
Wood framed and
other
R-13 +
R-3.8ci or
R-20
R-13 +
R-3.8ci or
R-20
R-13 +
R-3.8ci or
R-20
R-13 +
R-3.8ci or
R-20
R-13 +
R-3.8ci or
R-20
R-13 +
R-3.8ci or
R-20
R-13 +
R-3.8ci or
R-20
R-13 +
R-3.8ci or
R-20
R-13 +
R-3.8ci or
R-20
R-13 +
R-7.5ci or
R-20 +
R-3.8ci
R-13 +
R-7.5ci or
R-20 +
R-3.8ci
R-13 +
R-7.5ci or
R-20 +
R-3.8ci
R-13 +
R-7.5ci or
R-20 +
R-3.8ci
R-13 +
R-7.5ci or
R-20 +
R-3.8ci
R13 +
R-15.6ci or
R-20 +
R-10ci
R13 +
R-15.6ci or
R-20 +
R-10ci
Walls, below grade
Below-grade walldNRNRNRNRNRNRR-7.5ciR-7.5ciR-7.5ciR-7.5ciR-7.5ciR-7.5ciR-10ciR-10ciR-10ciR-12.5ci
Floors
MasseNRNRR-6.3ciR-8.3ciR-10ciR-10ciR-10ciR-10.4ciR-10ciR-12.5ciR-12.5ciR-12.5ciR-15ciR-16.7ciR-15ciR-16.7ci
Joist/framingNRNRR-30R-30R-30R-30R-30R-30R-30R-30R-30R-30fR-30fR-30fR-30fR-30f
Slab-on-grade floors
Unheated slabsNRNRNRNRNRNRR-10 for
24″ below
R-10 for
24″ below
R-10 for
24″ below
R-10 for
24″ below
R-10 for
24″ below
R-15 for
24″ below
R-15 for
24″ below
R-15 for
24″ below
R-15 for
24″ below
R-20 for
24″ below
Heated slabshR-7.5 for
12″ below
+ R-5 full slab
R-7.5 for
12″ below
+ R-5 full slab
R-7.5 for
12″ below
+ R-5 full slab
R-7.5 for
12″ below
+ R-5 full slab
R-10 for
24″ below
+ R-5 full slab
R-10 for
24″ below
+ R-5 full slab
R-15 for
24″ below
+ R-5 full slab
R-15 for
24″ below
+ R-5 full slab
R-15 for
36″ below
+ R-5 full slab
R-15 for
36″ below
+ R-5 full slab
R-15 for
36″ below
+ R-5 full slab
R-20 for
48″ below
+ R-5 full slab
R-20 for
48″ below
+ R-5 full slab
R-20 for
48″ below
+ R-5 full slab
R-20 for
48″ below
+ R-5 full slab
R-20 for
48″ below
+ R-5 full slab
Opaque doors
NonswingingR-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75R-4.75

For SI: 1 inch = 25.4 mm, 1 pound per square foot = 4.88 kg/m2, 1 pound per cubic foot = 16 kg/m3.

ci = Continuous insulation, NR = No Requirement, LS = Liner System.

  1. Assembly descriptions can be found in ANSI/ASHRAE/IESNA Appendix A.
  2. Where using R-value compliance method, a thermal spacer block shall be provided, otherwise use the U-factor compliance method in Table C402.1.4.
  3. R-5.7ci is allowed to be substituted with concrete block walls complying with ASTM C90, ungrouted or partially grouted at 32 inches or less on center vertically and 48 inches or less on center horizontally, with ungrouted cores filled with materials having a maximum thermal conductivity of 0.44 Btu-in/h-f2 °F.
  4. Where heated slabs are below grade, below-grade walls shall comply with the exterior insulation requirements for heated slabs.
  5. “Mass floors” shall be in accordance with Section C402.2.3.
  6. Steel floor joist systems shall be insulated to R-38.
  7. “Mass walls” shall be in accordance with Section C402.2.2.
  8. The first value is for perimeter insulation and the second value is for slab insulation. Perimeter insulation is not required to extend below the bottom of the slab.
  9. Not applicable to garage doors. See Table C402.1.4.

Building thermal envelope opaque assemblies shall meet the requirements of Sections C402.2 and C402.4 based on the climate zone specified in Chapter 3. Building thermal envelope opaque assemblies intended to comply on an assembly U-, C- or F-factor basis shall have a U-, C- or F-factor not greater than that specified in Table C402.1.4. Commercial buildings or portions of commercial buildings enclosing Group R occupancies shall use the U-, C- or F-factor from the “Group R” column of Table C402.1.4. Commercial buildings or portions of commercial buildings enclosing occupancies other than Group R shall use the U-, C- or F-factor from the “All other” column of Table C402.1.4

TABLE C402.1.4

OPAQUE THERMAL ENVELOPE ASSEMBLY MAXIMUM REQUIREMENTS, U-FACTOR METHODa, b

CLIMATE ZONE1234
EXCEPT MARINE
5
AND MARINE 4
678
All otherGroup RAll otherGroup RAll otherGroup RAll otherGroup RAll otherGroup RAll otherGroup RAll otherGroup RAll otherGroup R
Roofs
Insulation entirely
above roof deck
U-0.048U-0.039U-0.039U-0.039U-0.039U-0.039U-0.032U-0.032U-0.032U-0.032U-0.032U-0.032U-0.028U-0.028U-0.028U-0.028
Metal buildingsU-0.044U-0.035U-0.035U-0.035U-0.035U-0.035U-0.035U-0.035U-0.035U-0.035U-0.031U-0.031U-0.029U-0.029U-0.029U-0.029
Attic and otherU-0.027U-0.027U-0.027U-0.027U-0.027U-0.027U-0.027U-0.027U-0.027U-0.021U-0.021U-0.021U-0.021U-0.021U-0.021U-0.021
Walls, above grade
MassgU-0.151U-0.151U-0.151U-0.123U-0.123U-0.104U-0.104U-0.090U-0.090U-0.080U-0.080U-0.071U-0.071U-0.071U-0.061U-0.061
Metal buildingU-0.079U-0.079U-0.079U-0.079U-0.079U-0.052U-0.052U-0.052U-0.052U-0.052U-0.052U-0.052U-0.052U-0.039U-0.052U-0.039
Metal framedU-0.077U-0.077U-0.077U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.052U-0.064U-0.045
Wood framed and
otherc
U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.064U-0.051U-0.051U-0.051U-0.051U-0.036U-0.036
Walls, below grade
Below-grade wallcC-1.140eC-1.140eC-1.140eC-1.140eC-1.140eC-1.140eC-0.119C-0.119C-0.119C-0.119C-0.119C-0.119C-0.092C-0.092C-0.092C-0.092
Floors
MassdU-0.322eU-0.322eU-0.107U-0.087U-0.076U-0.076U-0.076U-0.074U-0.074U-0.064U-0.064U-0.064U-0.055U-0.051U-0.055U-0.051
Joist/framingU-0.066eU-0.066eU-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033U-0.033
Slab-on-grade floors
Unheated slabsF-0.73eF-0.73eF-0.73eF-0.73eF-0.73eF-0.73eF-0.54F-0.54F-0.54F-0.54F-0.54F-0.52F-0.40F-0.40F-0.40F-0.40
Heated slabsfF-1.02
0.74
F-1.02
0.74
F-1.02
0.74
F-1.02
0.74
F-0.90
0.74
F-0.90
0.74
F-0.86
0.64
F-0.86
0.64
F-0.79
0.64
F-0.79
0.64
F-0.79
0.55
F-0.69
0.55
F-0.69
0.55
F-0.69
0.55
F-0.69
0.55
F-0.69
0.55
Opaque doors
Swinging doorU-0.61U-0.61U-0.61U-0.61U-0.61U-0.61U-0.61U-0.61U-0.37U-0.37U-0.37U-0.37U-0.37U-0.37U-0.37U-0.37
Garage door <14%
glazing
U-0.31U-0.31U-0.31U-0.31U-0.31U-0.31U-0.31U-0.31U-0.31U-0.31U-0.31U-0.31U-0.31U-0.31U-0.31U-0.31

For SI: 1 pound per square foot = 4.88 kg/m2, 1 pound per cubic foot = 16 kg/m3.

ci = Continuous insulation, NR = No Requirement, LS = Liner System.

  1. Where assembly U-factors, C-factors, and F-factors are established in ANSI/ASHRAE/IESNA 90.1 Appendix A, such opaque assemblies shall be a compliance alternative where those values meet the criteria of this table, and provided that the construction, excluding the cladding system on walls, complies with the appropriate construction details from ANSI/ASHRAE/ISNEA 90.1 Appendix A.
  2. Where U-factors have been established by testing in accordance with ASTM C1363, such opaque assemblies shall be a compliance alternative where those values meet the criteria of this table. The R-value of continuous insulation shall be permitted to be added to or subtracted from the original tested design.
  3. Where heated slabs are below grade, below-grade walls shall comply with the U-factor requirements for above-grade mass walls.
  4. “Mass floors” shall be in accordance with Section C402.2.3.
  5. These C-, F- and U-factors are based on assemblies that are not required to contain insulation.
  6. The first value is for perimeter insulation and the second value is for full slab insulation.
  7. “Mass walls” shall be in accordance with Section C402.2.2.

U-factors of walls with cold-formed steel studs shall be permitted to be determined in accordance with Equation 4-1

(Equation 4-1)

where:

Rs = The cumulative R-value of the wall components along the path of heat transfer, excluding the cavity insulation and steel studs.

ER = The effective R-value of the cavity insulation with steel studs as specified in Table C402.1.4.1.

TABLE C402.1.4.1

EFFECTIVE R-VALUES FOR STEEL STUD WALL ASSEMBLIES

NOMINAL STUD DEPTH
(inches)
SPACING OF FRAMING
(inches)
CAVITY R-VALUE
(insulation)
CORRECTION FACTOR
(Fc)
EFFECTIVE R-VALUE (ER)
(Cavity R-Value × Fc)
31/216130.465.98
150.436.45
31/224130.557.15
150.527.80
616190.377.03
210.357.35
624190.458.55
210.439.03
816250.317.75
24250.389.50

Building envelope values and fenestration areas determined in accordance with Equation 4-2 shall be an alternative to compliance with the U-, F- and C-factors in Tables C402.1.4 and C402.4 and the maximum allowable fenestration areas in Section C402.4.1. Fenestration shall meet the applicable SHGC requirements of Section C402.4.3.

(Equation 4-2)

where:

A = Sum of the (UA Dif) values for each distinct assembly type of the building thermal envelope, other than slabs on grade and below-grade walls.

UA Dif = UA Proposed - UA Table.

UA Proposed = Proposed U-value x Area.

UA Table = (U-factor from Table C402.1.3, C402.1.4 or C402.4 x Area.

B = Sum of the (FL Dif) values for each distinct slab-on-grade perimeter condition of the building thermal envelope.

FL Dif = FL Proposed - FL Table.

FL Proposed = Proposed F-value x Perimeter length.

FL Table = (F-factor specified in Table C402.1.4) x Perimeter length.

C = Sum of the (CA Dif) values for each distinct below-grade wall assembly type of the building thermal envelope.

CA Dif = CA Proposed - CA Table.

CA Proposed = Proposed C-value x Area.

CA Table = (Maximum allowable C-factor specified in Table C402.1.4) x Area.

Where the proposed vertical glazing area is less than or equal to the maximum vertical glazing area allowed by Section C402.4.1, the value of D (Excess Vertical Glazing Value) shall be zero. Otherwise:

D = (DA x UV) - (DA x U Wall), but not less than zero.

DA = (Proposed Vertical Glazing Area) -(Vertical Glazing Area allowed by Section C402.4.1).

UA Wall = Sum of the (UA Proposed) values for each opaque assembly of the exterior wall.

U Wall = Area-weighted average U-value of all above-grade wall assemblies.

UAV = Sum of the (UA Proposed) values for each vertical glazing assembly.

UV = UAV/total vertical glazing area.

Where the proposed skylight area is less than or equal to the skylight area allowed by Section C402.4.1, the value of E (Excess Skylight Value) shall be zero. Otherwise:

E = (EA x US) - (EA x U Roof), but not less than zero.

EA = (Proposed Skylight Area) - (Allowable Skylight Area as specified in Section C402.4.1).

U Roof = Area-weighted average U-value of all roof assemblies.

UAS = Sum of the (UA Proposed) values for each skylight assembly.

US = UAS/total skylight area.

Insulation in building thermal envelope opaque assemblies shall comply with Sections C402.2.1 through C402.2.7 and Table C402.1.3.

The minimum thermal resistance (R-value) of the insulating material installed either between the roof framing or continuously on the roof assembly shall be as specified in Table C402.1.3, based on construction materials used in the roof assembly. Insulation installed on a suspended ceiling having removable ceiling tiles shall not be considered as part of the minimum thermal resistance of the roof insulation. Continuous insulation board shall be installed in not less than 2 layers and the edge joints between each layer of insulation shall be staggered.

Exceptions:

  1. Continuously insulated roof assemblies where the thickness of insulation varies 1 inch (25 mm) or less and where the area-weighted U-factor is equivalent to the same assembly with the R-value specified in Table C402.1.3.
  2. Where tapered insulation is used with insulation entirely above deck, the R-value where the insulation thickness varies 1 inch (25 mm) or less from the minimum thickness of tapered insulation shall comply with the R-value specified in Table C402.1.3.
  3. Two layers of insulation are not required where insulation tapers to the roof deck, such as at roof drains.

Skylight curbs shall be insulated to the level of roofs with insulation entirely above the deck or R-5, whichever is less.

Exception: Unit skylight curbs included as a component of a skylight listed and labeled in accordance with NFRC 100 shall not be required to be insulated.

The minimum thermal resistance (R-value) of materials installed in the wall cavity between framing members and continuously on the walls shall be as specified in Table C402.1.3, based on framing type and construction materials used in the wall assembly. The R-value of integral insulation installed in concrete masonry units shall not be used in determining compliance with Table C402.1.3 except as otherwise noted in the table. In determining compliance with Table C402.1.4, the use of the U-factor of concrete masonry units with integral insulation shall be permitted.

“Mass walls” where used as a component in the thermal envelope of a building shall comply with one of the following:

  1. Weigh not less than 35 pounds per square foot (171 kg/m2) of wall surface area.
  2. Weigh not less than 25 pounds per square foot (122 kg/m2) of wall surface area where the material weight is not more than 120 pcf (1900 kg/m3).
  3. Have a heat capacity exceeding 7 Btu/ft2 • °F (144 kJ/m2 • K).
  4. Have a heat capacity exceeding 5 Btu/ft2 • °F (103 kJ/m2 • K), where the material weight is not more than 120 pcf (1900 kg/m3).

The thermal properties (component R-values or assembly U-, C- or F-factors) of floor assemblies over outdoor air or unconditioned space shall be as specified in Table C402.1.3 or C402.1.4 based on the construction materials used in the floor assembly. Floor framing cavity insulation or structural slab insulation shall be installed to maintain permanent contact with the underside of the subfloor decking or structural slabs.

“Mass floors” where used as a component of the thermal envelope of a building shall provide one of the following weights:

  1. 35 pounds per square foot (171 kg/m2) of floor surface area.
  2. 25 pounds per square foot (122 kg/m2) of floor surface area where the material weight is not more than 120 pounds per cubic foot. (1923 kg/m3)

Exceptions:

  1. The floor framing cavity insulation or structural slab insulation shall be permitted to be in contact with the top side of sheathing or continuous insulation installed on the bottom side of floor assemblies where combined with insulation that meets or exceeds the minimum R-value in Table C402.1.3 for “Metal framed” or “Wood framed and other” values for “Walls, Above Grade” and extends from the bottom to the top of all perimeter floor framing or floor assembly members.
  2. Insulation applied to the underside of concrete floor slabs shall be permitted an airspace of not more than 1 inch (25 mm) where it turns up and is in contact with the underside of the floor under walls associated with the building thermal envelope.

Where the slab on grade is in contact with the ground, the minimum thermal resistance (R-value) of the insulation around the perimeter of unheated or heated slab-on-grade floors designed in accordance with the R-value method of Section C402.1.3 shall be as specified in Table C402.1.3. The perimeter insulation shall be placed on the outside of the foundation or on the inside of the foundation wall. The perimeter insulation shall extend downward from the top of the slab for the minimum distance shown in the table or to the top of the footing, whichever is less, or downward to not less than the bottom of the slab and then horizontally to the interior or exterior for the total distance shown in the table. Insulation extending away from the building shall be protected by pavement or by not less than of 10 inches (254 mm) of soil.

Exception: Where the slab-on-grade floor is greater than 24 inches (61 mm) below the finished exterior grade, perimeter insulation is not required.

The C-factor for the below-grade exterior walls shall be in accordance with Table C402.1.4. The R-value of the insulating material installed continuously within or on the below-grade exterior walls of the building envelope shall be in accordance with Table C402.1.3. The C-factor or R-value required shall extend to a depth of not less than 10 feet (3048 mm) below the outside finished ground level, or to the level of the lowest floor of the conditioned space enclosed by the below-grade wall, whichever is less.

Radiant heating system panels, and their associated components that are installed in interior or exterior assemblies shall be insulated to an R-value of not less than R-3.5 on all surfaces not facing the space being heated. Radiant heating system panels that are installed in the building thermal envelope shall be separated from the exterior of the building or unconditioned or exempt spaces by not less than the R-value of insulation installed in the opaque assembly in which they are installed or the assembly shall comply with Section C402.1.4.

Exception: Heated slabs on grade insulated in accordance with Section C402.2.4.

Where the thermal properties of airspaces are used to comply with this code in accordance with Section C401.2, such airspaces shall be enclosed in an unventilated cavity constructed to minimize airflow into and out of the enclosed airspace. Airflow shall be deemed minimized where the enclosed airspace is located on the interior side of the continuous air barrier and is bounded on all sides by building components.

Exception: The thermal resistance of airspaces located on the exterior side of the continuous air barrier and adjacent to and behind the exterior wall-covering material shall be determined in accordance with ASTM C1363 modified with an airflow entering the bottom and exiting the top of the airspace at an air movement rate of not less than 70 mm/second.

Low-sloped roofs directly above cooled conditioned spaces in Climate Zones 1, 2 and 3 shall comply with one or more of the options in Table C402.3.

Exceptions: The following roofs and portions of roofs are exempt from the requirements of Table C402.3:

  1. Portions of the roof that include or are covered by the following:

    1. 1.1. Photovoltaic systems or components.
    2. 1.2. Solar air or water-heating systems or components.
    3. 1.3. Roof gardens or landscaped roofs.
    4. 1.4. Above-roof decks or walkways.
    5. 1.5. Skylights.
    6. 1.6. HVAC systems and components, and other opaque objects mounted above the roof.
  2. Portions of the roof shaded during the peak sun angle on the summer solstice by permanent features of the building or by permanent features of adjacent buildings.
  3. Portions of roofs that are ballasted with a minimum stone ballast of 17 pounds per square foot [74 kg/m2] or 23 psf [117 kg/m2] pavers.
  4. Roofs where not less than 75 percent of the roof area complies with one or more of the exceptions to this section.

TABLE C402.3

MINIMUM ROOF REFLECTANCE AND EMITTANCE OPTIONSa

Three-year-aged solar reflectance indexb of 55 and 3-year aged thermal emittancec of 0.75
Three-year-aged solar reflectance indexd of 64
  1. The use of area-weighted averages to comply with these requirements shall be permitted. Materials lacking 3-year-aged tested values for either solar reflectance or thermal emittance shall be assigned both a 3-year-aged solar reflectance in accordance with Section C402.3.1 and a 3-year-aged thermal emittance of 0.90.
  2. Aged solar reflectance tested in accordance with ASTM C1549, ASTM E903 or ASTM E1918 or CRRC-S100.
  3. Aged thermal emittance tested in accordance with ASTM C1371 or ASTM E408 or CRRC-S100.
  4. Solar reflectance index (SRI) shall be determined in accordance with ASTM E1980 using a convection coefficient of 2.1 Btu/h • ft2 • °F (12W/m2 • K). Calculation of aged SRI shall be based on aged tested values of solar reflectance and thermal emittance.

Where an aged solar reflectance required by Section C402.3 is not available, it shall be determined in accordance with Equation 4-3.

(Equation 4-3)

where:

Raged = The aged solar reflectance.

Rinitial = The initial solar reflectance determined in accordance with CRRC-S100.

Fenestration shall comply with Sections C402.4.1 through C402.4.5 and Table C402.4. Daylight responsive controls shall comply with this section and Section C405.2.3.1.

TABLE C402.4

BUILDING ENVELOPE FENESTRATION MAXIMUM U-FACTOR AND SHGC REQUIREMENTS

CLIMATE ZONE1234 EXCEPT
MARINE
5 AND
MARINE 4
678
Vertical fenestration
U-factor
Fixed fenestration0.500.500.460.380.380.360.290.29
Operable fenestration0.650.650.600.450.450.430.370.37
Entrance doors1.100.830.770.770.770.770.770.77
SHGC
OrientationaSEWNSEWNSEWNSEWNSEWNSEWNSEWNSEWN
PF < 0.20.250.330.250.330.250.330.360.480.380.510.400.530.45NR0.45N
0.2 ≤ PF < 0.50.300.370.300.370.300.370.430.530.460.560.480.58NRNRNRNR
PF ≥ 0.50.400.400.400.400.400.400.580.580.610.610.640.64NRNRNRNR
Skylights
U-factor0.750.650.550.500.500.500.500.50
SHGC0.350.350.350.400.400.40NRNR

NR = No Requirement, PF = Projection Factor.

  1. “N” indicates vertical fenestration oriented within 45 degrees of true north. “SEW” indicates orientations other than “N.” For buildings in the southern hemisphere, reverse south and north. Buildings located at less than 23.5 degrees latitude shall use SEW for all orientations.
The vertical fenestration area, not including opaque doors and opaque spandrel panels, shall be not greater than 30 percent of the gross above-grade wall area. The skylight area shall be not greater than 3 percent of the gross roof area.

In Climate Zones 1 through 6, not more than 40 percent of the gross above-grade wall area shall be vertical fenestration, provided that all of the following requirements are met:

  1. In buildings not greater than two stories above grade, not less than 50 percent of the net floor area is within a daylight zone.
  2. In buildings three or more stories above grade, not less than 25 percent of the net floor area is within a daylight zone.
  3. Daylight responsive controls complying with Section C405.2.3.1 are installed in daylight zones.
  4. Visible transmittance (VT) of vertical fenestration is not less than 1.1 times solar heat gain coefficient (SHGC).

    Exception: Fenestration that is outside the scope of NFRC 200 is not required to comply with Item 4.

The skylight area shall be not more than 6 percent of the roof area provided that daylight responsive controls complying with Section C405.2.3.1 are installed in toplit zones.

In an enclosed space greater than 2,500 square feet (232 m2) in floor area, directly under a roof with not less than 75 percent of the ceiling area with a ceiling height greater than 15 feet (4572 mm), and used as an office, lobby, atrium, concourse, corridor, storage space, gymnasium/exercise center, convention center, automotive service area, space where manufacturing occurs, nonrefrigerated warehouse, retail store, distribution/sorting area, transportation depot or workshop, the total toplit daylight zone shall be not less than half the floor area and shall provide one of the following:

  1. A minimum skylight area to toplit daylight zone of not less than 3 percent where all skylights have a VT of not less than 0.40 as determined in accordance with Section C303.1.3.
  2. A minimum skylight effective aperture of not less than 1 percent, determined in accordance with Equation 4-4.

    (Equation 4-4)

    where:

    Skylight area = Total fenestration area of skylights.

    Skylight VT = Area weighted average visible transmittance of skylights.

    WF = Area weighted average well factor, where well factor is 0.9 if light well depth is less than 2 feet (610 mm), or 0.7 if light well depth is 2 feet (610 mm) or greater.

    Light well depth = Measure vertically from the underside of the lowest point of the skylight glazing to the ceiling plane under the skylight.

Exception: Skylights above daylight zones of enclosed spaces are not required in:

  1. Buildings in Climate Zones 6 through 8.
  2. Spaces where the designed general lighting power densities are less than 0.5 W/ft2 (5.4 W/m2).
  3. Areas where it is documented that existing structures or natural objects block direct beam sunlight on not less than half of the roof over the enclosed area for more than 1,500 daytime hours per year between 8 a.m. and 4 p.m.
  4. Spaces where the daylight zone under rooftop monitors is greater than 50 percent of the enclosed space floor area.
  5. Spaces where the total area minus the area of sidelight daylight zones is less than 2,500 square feet (232 m2), and where the lighting is controlled in accordance with Section C405.2.3.
Daylight responsive controls complying with Section C405.2.3.1 shall be provided to control all electric lights within toplit zones.

Skylights in office, storage, automotive service, manufacturing, nonrefrigerated warehouse, retail store and distribution/sorting area spaces shall have a glazing material or diffuser with a haze factor greater than 90 percent when tested in accordance with ASTM D1003.

Exception: Skylights designed and installed to exclude direct sunlight entering the occupied space by the use of fixed or automated baffles or the geometry of skylight and light well.

The maximum U-factor and solar heat gain coefficient (SHGC) for fenestration shall be as specified in Table C402.4.

The window projection factor shall be determined in accordance with Equation 4-5.

(Equation 4-5)

where:

PF = Projection factor (decimal).

A = Distance measured horizontally from the farthest continuous extremity of any overhang, eave or permanently attached shading device to the vertical surface of the glazing.

B = Distance measured vertically from the bottom of the glazing to the underside of the overhang, eave or permanently attached shading device.

Where different windows or glass doors have different PF values, they shall each be evaluated separately.

In Climate Zones 1 through 6, skylights shall be permitted a maximum SHGC of 0.60 where located above daylight zones provided with daylight responsive controls.
Where skylights are installed above daylight zones provided with daylight responsive controls, a maximum U-factor of 0.9 shall be permitted in Climate Zones 1 through 3 and a maximum U-factor of 0.75 shall be permitted in Climate Zones 4 through 8.

Where dynamic glazing is intended to satisfy the SHGC and VT requirements of Table C402.4, the ratio of the higher to lower labeled SHGC shall be greater than or equal to 2.4, and the dynamic glazing shall be automatically controlled to modulate the amount of solar gain into the space in multiple steps. Dynamic glazing shall be considered separately from other fenestration, and area-weighted averaging with other fenestration that is not dynamic glazing shall not be permitted.

Exception: Dynamic glazing is not required to comply with this section where both the lower and higher labeled SHGC already comply with the requirements of Table C402.4.

An area-weighted average shall be permitted to satisfy the U-factor requirements for each fenestration product category listed in Table C402.4. Individual fenestration products from different fenestration product categories listed in Table C402.4 shall not be combined in calculating area-weighted average U-factor.
Daylight zones referenced in Sections C402.4.1.1 through C402.4.3.2 shall comply with Sections C405.2.3.2 and C405.2.3.3, as applicable. Daylight zones shall include toplit zones and sidelit zones.
Opaque swinging doors shall comply with Table C402.1.4. Opaque nonswinging doors shall comply with Table C402.1.3. Opaque doors shall be considered as part of the gross area of above-grade walls that are part of the building thermal envelope. Other doors shall comply with the provisions of Section C402.4.3 for vertical fenestration.
The thermal envelope of buildings shall comply with Sections C402.5.1 through C402.5.8, or the building thermal envelope shall be tested in accordance with ASTM E 779 at a pressure differential of 0.3 inch water gauge (75 Pa) or an equivalent method approved by the code official and deemed to comply with the provisions of this section when the tested air leakage rate of the building thermal envelope is not greater than 0.40 cfm/ft2 (2.0 L/s • m2). Where compliance is based on such testing, the building shall also comply with Sections C402.5.5, C402.5.6 and C402.5.7.

A continuous air barrier shall be provided throughout the building thermal envelope. The air barriers shall be permitted to be located on the inside or outside of the building envelope, located within the assemblies composing the envelope, or any combination thereof. The air barrier shall comply with Sections C402.5.1.1 and C402.5.1.2.

Exception: Air barriers are not required in buildings located in Climate Zone 2B.

The continuous air barrier shall be constructed to comply with the following:

  1. The air barrier shall be continuous for all assemblies that are the thermal envelope of the building and across the joints and assemblies.
  2. Air barrier joints and seams shall be sealed, including sealing transitions in places and changes in materials. The joints and seals shall be securely installed in or on the joint for its entire length so as not to dislodge, loosen or otherwise impair its ability to resist positive and negative pressure from wind, stack effect and mechanical ventilation.
  3. Penetrations of the air barrier shall be caulked, gasketed or otherwise sealed in a manner compatible with the construction materials and location. Sealing shall allow for expansion, contraction and mechanical vibration. Joints and seams associated with penetrations shall be sealed in the same manner or taped. Sealing materials shall be securely installed around the penetration so as not to dislodge, loosen or otherwise impair the penetrations’ ability to resist positive and negative pressure from wind, stack effect and mechanical ventilation. Sealing of concealed fire sprinklers, where required, shall be in a manner that is recommended by the manufacturer. Caulking or other adhesive sealants shall not be used to fill voids between fire sprinkler cover plates and walls or ceilings.
  4. Recessed lighting fixtures shall comply with Section C402.5.8. Where similar objects are installed that penetrate the air barrier, provisions shall be made to maintain the integrity of the air barrier.
A continuous air barrier for the opaque building envelope shall comply with Section C402.5.1.2.1 or C402.5.1.2.2.

Materials with an air permeability not greater than 0.004 cfm/ft2 (0.02 L/s • m2) under a pressure differential of 0.3 inch water gauge (75 Pa) when tested in accordance with ASTM E2178 shall comply with this section. Materials in Items 1 through 16 shall be deemed to comply with this section, provided that joints are sealed and materials are installed as air barriers in accordance with the manufacturer’s instructions.

  1. Plywood with a thickness of not less than 3/8 inch (10 mm).
  2. Oriented strand board having a thickness of not less than 3/8 inch (10 mm).
  3. Extruded polystyrene insulation board having a thickness of not less than 1/2 inch (12.7 mm).
  4. Foil-back polyisocyanurate insulation board having a thickness of not less than 1/2 inch (12.7 mm).
  5. Closed-cell spray foam having a minimum density of 1.5 pcf (2.4 kg/m3) and having a thickness of not less than 11/2 inches (38 mm).
  6. Open-cell spray foam with a density between 0.4 and 1.5 pcf (0.6 and 2.4 kg/m3) and having a thickness of not less than 4.5 inches (113 mm).
  7. Exterior or interior gypsum board having a thickness of not less than 1/2 inch (12.7 mm).
  8. Cement board having a thickness of not less than 1/2 inch (12.7 mm).
  9. Built-up roofing membrane.
  10. Modified bituminous roof membrane.
  11. Fully adhered single-ply roof membrane.
  12. A Portland cement/sand parge, or gypsum plaster having a thickness of not less than 5/8 inch (15.9 mm).
  13. Cast-in-place and precast concrete.
  14. Fully grouted concrete block masonry.
  15. Sheet steel or aluminum.
  16. Solid or hollow masonry constructed of clay or shale masonry units.

Assemblies of materials and components with an average air leakage not greater than 0.04 cfm/ft2 (0.2 L/s • m2) under a pressure differential of 0.3 inch of water gauge (w.g.)(75 Pa) when tested in accordance with ASTM E2357, ASTM E1677 or ASTM E283 shall comply with this section. Assemblies listed in Items 1 through 3 shall be deemed to comply, provided that joints are sealed and the requirements of Section C402.5.1.1 are met.

  1. Concrete masonry walls coated with either one application of block filler or two applications of a paint or sealer coating.
  2. Masonry walls constructed of clay or shale masonry units with a nominal width of 4 inches (102 mm) or more.
  3. A Portland cement/sand parge, stucco or plaster not less than 1/2 inch (12.7 mm) in thickness.

The air leakage of fenestration assemblies shall meet the provisions of Table C402.5.2. Testing shall be in accordance with the applicable reference test standard in Table C402.5.2 by an accredited, independent testing laboratory and labeled by the manufacturer.

Exceptions:

  1. Field-fabricated fenestration assemblies that are sealed in accordance with Section C402.5.1.
  2. Fenestration in buildings that comply with the testing alternative of Section C402.5 are not required to meet the air leakage requirements in Table C402.5.2.

TABLE C402.5.2

MAXIMUM AIR LEAKAGE RATE FOR FENESTRATION ASSEMBLIES

FENESTRATION ASSEMBLYMAXIMUM
RATE (CFM/FT2)
TEST PROCEDURE
Windows0.20 aAAMA/WDMA/CSA101/I.S.2/A440
or
NFRC 400
Sliding doors0.20 a
Swinging doors0.20 a
Skylights – with condensation
weepage openings
0.30
Skylights – all other0.20 a
Curtain walls0.06NFRC 400
or
ASTM E283 at 1.57 psf
(75 Pa)
Storefront glazing0.06
Commercial glazed
swinging entrance doors
1.00
Power-operated sliding
doors and power
operated folding doors
1.00
Revolving doors1.00
Garage doors0.40ANSI/DASMA 105,
NFRC 400, or
ASTM E283 at 1.57 psf
(75 Pa)
Rolling doors1.00
High-speed doors1.30

For SI: 1 cubic foot per minute = 0.47 L/s, 1 square foot = 0.093 m2.

  1. The maximum rate for windows, sliding and swinging doors, and skylights is permitted to be 0.3 cfm per square foot of fenestration or door area when tested in accordance with AAMA/WDMA/CSA101/I.S.2/A440 at 6.24 psf (300 Pa).

In Climate Zones 3 through 8, where combustion air is supplied through openings in an exterior wall to a room or space containing a space-conditioning fuel-burning appliance, one of the following shall apply:

  1. The room or space containing the appliance shall be located outside of the building thermal envelope.
  2. The room or space containing the appliance shall be enclosed and isolated from conditioned spaces in-side the building thermal envelope. Such rooms shall comply with all of the following:

    1. 2.1. The walls, floors and ceilings that separate the enclosed room or space from conditioned spaces shall be insulated to be not less than equivalent to the insulation requirement of below-grade walls as specified in Table C402.1.3 or C402.1.4.
    2. 2.2. The walls, floors and ceilings that separate the enclosed room or space from conditioned spaces shall be sealed in accordance with Section C402.5.1.1.
    3. 2.3. The doors into the enclosed room or space shall be shall be fully gasketed.
    4. 2.4. Water lines and ducts in the enclosed room or space shall be insulated in accordance with Section C403.
    5. 2.5. Where an air duct supplying combustion air to the enclosed room or space passes through conditioned space, the duct shall be insulated to an R-value of not less than R-8.

Exception: Fireplaces and stoves complying with Sections 901 through 905 of the International Mechanical Code, and Section 2111.14 of the International Building Code.

Doors and access openings from conditioned space to shafts, chutes stairways and elevator lobbies not within the scope of the fenestration assemblies covered by Section C402.5.2 shall be gasketed, weatherstripped or sealed.

Exceptions:

  1. Door openings required to comply with Section 716 of the International Building Code.
  2. Doors and door openings required to comply with UL 1784 by the International Building Code.
Stairway enclosures, elevator shaft vents and other outdoor air intakes and exhaust openings integral to the building envelope shall be provided with dampers in accordance with Section C403.7.7.
Cargo door openings and loading door openings shall be equipped with weatherseals that restrict infiltration and provide direct contact along the top and sides of vehicles that are parked in the doorway.

Building entrances shall be protected with an enclosed vestibule, with all doors opening into and out of the vestibule equipped with self-closing devices. Vestibules shall be designed so that in passing through the vestibule it is not necessary for the interior and exterior doors to open at the same time. The installation of one or more revolving doors in the building entrance shall not eliminate the requirement that a vestibule be provided on any doors adjacent to revolving doors.

Exceptions: Vestibules are not required for the following:

  1. Buildings in Climate Zones 1 and 2.
  2. Doors not intended to be used by the public, such as doors to mechanical or electrical equipment rooms, or intended solely for employee use.
  3. Doors opening directly from a sleeping unit or dwelling unit.
  4. Doors that open directly from a space less than 3,000 square feet (298 m2) in area.
  5. Revolving doors.
  6. Doors used primarily to facilitate vehicular movement or material handling and adjacent personnel doors.
  7. Doors that have an air curtain with a velocity of not less than 6.56 feet per second (2 m/s) at the floor that have been tested in accordance with ANSI/AMCA 220 and installed in accordance with the manufacturer’s instructions. Manual or automatic controls shall be provided that will operate the air curtain with the opening and closing of the door. Air curtains and their controls shall comply with Section C408.2.3.

Recessed luminaires installed in the building thermal envelope shall be all of the following:

  1. IC-rated.
  2. Labeled as having an air leakage rate of not more 2.0 cfm (0.944 L/s) when tested in accordance with ASTM E283 at a 1.57 psf (75 Pa) pressure differential.
  3. Sealed with a gasket or caulk between the housing and interior wall or ceiling covering.
Mechanical systems and equipment serving the building heating, cooling, ventilating or refrigerating needs shall comply with this section.
Design loads associated with heating, ventilating and air conditioning of the building shall be determined in accordance with ANSI/ASHRAE/ACCA Standard 183 or by an approved equivalent computational procedure using the design parameters specified in Chapter 3. Heating and cooling loads shall be adjusted to account for load reductions that are achieved where energy recovery systems are utilized in the HVAC system in accordance with the ASHRAE HVAC Systems and Equipment Handbook by an approved equivalent computational procedure.
Mechanical systems shall be designed to comply with Sections C403.2.1 and C403.2.2. Where elements of a building’s mechanical systems are addressed in Sections C403.3 through C403.12, such elements shall comply with the applicable provisions of those sections.

HVAC systems serving zones that are over 25,000 square feet (2323 m2) in floor area or that span more than one floor and are designed to operate or be occupied nonsimultaneously shall be divided into isolation areas. Each isolation area shall be equipped with isolation devices and controls configured to automatically shut off the supply of conditioned air and outdoor air to and exhaust air from the isolation area. Each isolation area shall be controlled independently by a device meeting the requirements of Section C403.4.2.2. Central systems and plants shall be provided with controls and devices that will allow system and equipment operation for any length of time while serving only the smallest isolation area served by the system or plant.

Exceptions:

  1. Exhaust air and outdoor air connections to isolation areas where the fan system to which they connect is not greater than 5,000 cfm (2360 L/s).
  2. Exhaust airflow from a single isolation area of less than 10 percent of the design airflow of the exhaust system to which it connects.
  3. Isolation areas intended to operate continuously or intended to be inoperative only when all other isolation areas in a zone are inoperative.
Ventilation, either natural or mechanical, shall be provided in accordance with Chapter 4 of the International Mechanical Code. Where mechanical ventilation is provided, the system shall provide the capability to reduce the outdoor air supply to the minimum required by Chapter 4 of the International Mechanical Code.
Heating and cooling equipment installed in mechanical systems shall be sized in accordance with Section C403.3.1 and shall be not less efficient in the use of energy than as specified in Section C403.3.2.

The output capacity of heating and cooling equipment shall be not greater than that of the smallest available equipment size that exceeds the loads calculated in accordance with Section C403.1.1. A single piece of equipment providing both heating and cooling shall satisfy this provision for one function with the capacity for the other function as small as possible, within available equipment options.

Exceptions:

  1. Required standby equipment and systems provided with controls and devices that allow such systems or equipment to operate automatically only when the primary equipment is not operating.
  2. Multiple units of the same equipment type with combined capacities exceeding the design load and provided with controls that are configured to sequence the operation of each unit based on load.

Equipment shall meet the minimum efficiency requirements of Tables C403.3.2(1) through C403.3.2(9) when tested and rated in accordance with the applicable test procedure. Plate-type liquid-to-liquid heat exchangers shall meet the minimum requirements of Table C403.3.2(10). The efficiency shall be verified through certification under an approved certification program or, where a certification program does not exist, the equipment efficiency ratings shall be supported by data furnished by the manufacturer. Where multiple rating conditions or performance requirements are provided, the equipment shall satisfy all stated requirements. Where components, such as indoor or outdoor coils, from different manufacturers are used, calculations and supporting data shall be furnished by the designer that demonstrates that the combined efficiency of the specified components meets the requirements herein.

TABLE C403.3.2(1)

MINIMUM EFFICIENCY REQUIREMENTS: ELECTRICALLY OPERATED UNITARY AIR CONDITIONERS AND CONDENSING UNITS

EQUIPMENT TYPESIZE CATEGORYHEATING
SECTION TYPE
SUBCATEGORY OR
RATING CONDITION
MINIMUM EFFICIENCYTEST
PROCEDUREa
Air conditioners, air cooled< 65,000 Btu/hbAllSplit System13.0 SEERAHRI 210/240
Single Package14.0 SEER
Through-the-wall (air cooled)≤ 30,000 Btu/hbAllSplit system12.0 SEER
Single Package12.0 SEER
Small-duct high-velocity
(air cooled)
< 65,000 Btu/hbAllSplit System11.0 SEER
Air conditioners, air cooled≥ 65,000 Btu/h
and
< 135,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
11.2 EER
12.8 IEER
AHRI 340/360
All otherSplit System and
Single Package
11.0 EER
12.6 IEER
≥ 135,000 Btu/h
and
< 240,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
11.0 EER
12.4 IEER
All otherSplit System and
Single Package
10.8 EER
12.2 IEER
≥ 240,000 Btu/h
and
< 760,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
10.0 EER
11.6 IEER
All otherSplit System and
Single Package
9.8 EER
11.4 IEER
≥ 760,000 Btu/hElectric Resistance
(or None)
Split System and
Single Package
9.7 EER
11.2 IEER
All otherSplit System and
Single Package
9.5 EER
11.0 IEER
Air conditioners, water cooled< 65,000 Btu/hbAllSplit System and
Single Package
12.1 EER
12.3 IEER
AHRI 210/240
≥ 65,000 Btu/h
and
< 135,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
12.1 EER
13.9 IEER
AHRI 340/360
All otherSplit System and
Single Package
11.9 EER
13.7 IEER
≥ 135,000 Btu/h
and
< 240,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
12.5 EER
13.9 IEER
All otherSplit System and
Single Package
12.3 EER
13.7 IEER
≥ 240,000 Btu/h
and
< 760,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
12.4 EER
13.6 IEER
All otherSplit System and
Single Package
12.2 EER
13.4 IEER
≥ 760,000 Btu/hElectric Resistance
(or None)
Split System and
Single Package
12.2 EER
13.5 IEER
All otherSplit System and
Single Package
12.0 EER
13.3 IEER
Air conditioners,
evaporatively cooled
< 65,000 Btu/hbAllSplit System and
Single Package
12.1 EER
12.3 IEER
AHRI 210/240
≥ 65,000 Btu/h
and
< 135,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
12.1 EER
12.3 IEER
AHRI 340/360
All otherSplit System and
Single Package
11.9 EER
12.1 IEER
≥ 135,000 Btu/h
and
< 240,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
12.0 EER
12.2 IEER
All otherSplit System and
Single Package
11.8 EER
12.0 IEER
≥ 240,000 Btu/h
and
< 760,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
11.9 EER
12.1 IEER
All otherSplit System and
Single Package
11.7 EER
11.9 IEER
≥ 760,000 Btu/hElectric Resistance
(or None)
Split System and
Single Package
11.7 EER
11.9 IEER
All otherSplit System and
Single Package
11.5 EER
11.7 IEER
Condensing units, air cooled≥ 135,000 Btu/h10.5 EER
11.8 IEER
AHRI 365
Condensing units, water cooled≥ 135,000 Btu/h13.5 EER
14.0 IEER
Condensing units, evaporatively cooled≥ 135,000 Btu/h13.5 EER
14.0 IEER

For SI: 1 British thermal unit per hour = 0.2931 W.

  1. Chapter 6 contains a complete specification of the referenced test procedure, including the reference year version of the test procedure.
  2. Single-phase, air-cooled air conditioners less than 65,000 Btu/h are regulated by NAECA. SEER values are those set by NAECA.

TABLE C403.3.2(2)

MINIMUM EFFICIENCY REQUIREMENTS: ELECTRICALLY OPERATED UNITARY AND APPLIED HEAT PUMPS

EQUIPMENT TYPESIZE CATEGORYHEATING
SECTION TYPE
SUBCATEGORY OR
RATING CONDITION
MINIMUM
EFFICIENCY
TEST
PROCEDUREa
Air cooled (cooling mode)< 65,000 Btu/hbAllSplit System14.0 SEERAHRI 210/240
Single Package14.0 SEER
Through-the-wall, air cooled≤ 30,000 Btu/hbAllSplit System12.0 SEER
Single Package12.0 SEER
Single-duct high-velocity air cooled< 65,000 Btu/hbAllSplit System11.0 SEER
Air cooled (cooling mode)≥ 65,000 Btu/h and
< 135,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
11.0 EER
12.0 IEER
AHRI 340/360
All otherSplit System and
Single Package
10.8 EER
11.8 IEER
≥ 135,000 Btu/h and
< 240,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
10.6 EER
11.6 IEER
All otherSplit System and
Single Package
10.4 EER
11.4 IEER
≥ 240,000 Btu/hElectric Resistance
(or None)
Split System and
Single Package
9.5 EER
10.6 IEER
All otherSplit System and
Single Package
9.3 EER
9.4 IEER
Water to Air: Water Loop
(cooling mode)
< 17,000 Btu/hAll86°F entering water12.2 EERISO 13256-1
≥ 17,000 Btu/h and
< 65,000 Btu/h
All86°F entering water13.0 EER
≥ 65,000 Btu/h and
< 135,000 Btu/h
All86°F entering water13.0 EER
Water to Air: Ground Water
(cooling mode)
< 135,000 Btu/hAll59°F entering water18.0 EERISO 13256-1
Brine to Air: Ground Loop
(cooling mode)
< 135,000 Btu/hAll77°F entering water14.1 EERISO 13256-1
Water to Water: Water Loop
(cooling mode)
< 135,000 Btu/hAll86°F entering water10.6 EERISO 13256-2
Water to Water: Ground Water
(cooling mode)
< 135,000 Btu/hAll59°F entering water16.3 EER
Brine to Water: Ground Loop
(cooling mode)
< 135,000 Btu/hAll77°F entering fluid12.1 EER
Air cooled (heating mode)< 65,000 Btu/hbSplit System8.2 HSPFAHRI 210/240
Single Package8.0 HSPF
Through-the-wall,
(air cooled, heating mode)
≤ 30,000 Btu/hb (cooling capacity)Split System7.4 HSPF
Single Package7.4 HSPF
Small-duct high velocity
(air cooled, heating mode)
< 65,000 Btu/hbSplit System6.8 HSPF
Air cooled (heating mode)≥ 65,000 Btu/h and
< 135,000 Btu/h
(cooling capacity)
47°F db/43°F wb
outdoor air
3.3 COPAHRI 340/360
17°Fdb/15°F wb
outdoor air
2.25 COP
≥ 135,000 Btu/h
(cooling capacity)
47°F db/43°F wb
outdoor air
3.2 COP
17°Fdb/15°F wb
outdoor air
2.05 COP
Water to Air: Water Loop
(heating mode)
< 135,000 Btu/h
(cooling capacity)
68°F entering water4.3 COPISO 13256-1
Water to Air: Ground Water
(heating mode)
< 135,000 Btu/h
(cooling capacity)
50°F entering water3.7 COP
Brine to Air: Ground Loop
(heating mode)
< 135,000 Btu/h
(cooling capacity)
32°F entering fluid3.2 COP
Water to Water: Water Loop
(heating mode)
< 135,000 Btu/h
(cooling capacity)
68°F entering water3.7 COPISO 13256-2
Water to Water: Ground Water
(heating mode)
< 135,000 Btu/h
(cooling capacity)
50°F entering water3.1 COP
Brine to Water: Ground Loop
(heating mode)
< 135,000 Btu/h
(cooling capacity)
32°F entering fluid2.5 COP

For SI: 1 British thermal unit per hour = 0.2931 W, °C = [(°F) - 32]/1.8.

  1. Chapter 6 contains a complete specification of the referenced test procedure, including the reference year version of the test procedure.
  2. Single-phase, air-cooled heat pumps less than 65,000 Btu/h are regulated by NAECA. SEER and HSPF values are those set by NAECA.

TABLE C403.3.2(3)

MINIMUM EFFICIENCY REQUIREMENTS: ELECTRICALLY OPERATED PACKAGED TERMINAL AIR CONDITIONERS, PACKAGED TERMINAL HEAT PUMPS, SINGLE-PACKAGE VERTICAL AIR CONDITIONERS, SINGLE VERTICAL HEAT PUMPS, ROOM AIR CONDITIONERS AND ROOM AIR-CONDITIONER HEAT PUMPS

EQUIPMENT TYPESIZE CATEGORY (INPUT)SUBCATEGORY OR
RATING CONDITION
MINIMUM EFFICIENCYTEST
PROCEDUREa
PTAC (cooling mode)
new construction
All Capacities95°F db outdoor air14.0 - (0.300 × Cap/1000) EERAHRI 310/380
PTAC (cooling mode)
replacementsb
All Capacities95°F db outdoor air10.9 - (0.213 × Cap/1000) EER
PTHP (cooling mode)
new construction
All Capacities95°F db outdoor air14.0 - (0.300 × Cap/1000) EER
PTHP (cooling mode)
replacementsb
All Capacities95°F db outdoor air10.8 - (0.213 × Cap/1000) EER
PTHP (heating mode)
new construction
All Capacities3.2 - (0.026 × Cap/1000) COP
PTHP (heating mode)
replacementsb
All Capacities2.9 - (0.026 × Cap/1000) COP
SPVAC (cooling mode)< 65,000 Btu/h95°F db/ 75°F wb outdoor air9.0 EERAHRI 390
≥ 65,000 Btu/h and
< 135,000 Btu/h
95°F db/ 75°F wb outdoor air8.9 EER
≥ 135,000 Btu/h and
< 240,000 Btu/h
95°F db/ 75°F wb outdoor air8.6 EER
SPVHP (cooling mode)< 65,000 Btu/h95°F db/ 75°F wb outdoor air9.0 EER
≥ 65,000 Btu/h and
< 135,000 Btu/h
95°F db/ 75°F wb outdoor air8.9 EER
≥ 135,000 Btu/h and
< 240,000 Btu/h
95°F db/ 75°F wb outdoor air8.6 EER
SPVHP (heating mode)< 65,000 Btu/h47°F db/ 43°F wb outdoor air3.0 COPAHRI 390
≥ 65,000 Btu/h and
< 135,000 Btu/h
47°F db/ 43°F wb outdoor air3.0 COP
≥ 135,000 Btu/h and
< 240,000 Btu/h
47°F db/ 75°F wb outdoor air2.9 COP
Room air conditioners,
with louvered sides
< 6,000 Btu/h11.0 CEERANSI/AHAM RAC-1
≥ 6,000 Btu/h and
< 8,000 Btu/h
11.0 CEER
≥ 8,000 Btu/h and
< 14,000 Btu/h
10.9 CEER
≥ 14,000 Btu/h and
< 20,000 Btu/h
10.7 CEER
≥ 20,000 Btu/h and
≤ 25,000 Btu/h
9.4 CEER
> 25,000 Btu/h9.0 CEER
Room air conditioners,
without louvered sides
< 6,000 Btu/h10.0 CEER
≥ 6,000 Btu/h and
< 8,000 Btu/h
10.0 CEER
≥ 8,000 Btu/h and
< 11,000 Btu/h
9.6 CEER
≥ 11,000 Btu/h and
< 14,000 Btu/h
9.5 CEER
≥ 14,000 Btu/h and
< 20,000 Btu/h
9.3 CEER
≥ 20,000 Btu/h 9.4 CEER
Room air-conditioner
heat pumps with
louvered sides
< 20,000 Btu/h9.8 CEER
≥ 20,000 Btu/h9.3 CEER
Room air-conditioner
heat pumps without
louvered sides
< 14,000 Btu/h9.3 CEER
≥ 14,000 Btu/h8.7 CEER
Room air conditioner casement onlyAll capacities9.5 CEERANSI/AHAM RAC-1
Room air conditioner casement-sliderAll capacities10.4 CEER

For SI: 1 British thermal unit per hour = 0.2931 W, °C = [(°F) - 32]/1.8, wb = wet bulb, db = dry bulb.

“Cap” = The rated cooling capacity of the project in Btu/h. Where the unit’s capacity is less than 7000 Btu/h, use 7000 Btu/h in the calculation. Where the unit’s capacity is greater than 15,000 Btu/h, use 15,000 Btu/h in the calculations.

  1. Chapter 6 contains a complete specification of the referenced test procedure, including the referenced year version of the test procedure.
  2. Replacement unit shall be factory labeled as follows: “MANUFACTURED FOR REPLACEMENT APPLICATIONS ONLY: NOT TO BE INSTALLED IN NEW CONSTRUCTION PROJECTS.” Replacement efficiencies apply only to units with existing sleeves less than 16 inches (406 mm) in height and less than 42 inches (1067 mm) in width.

TABLE C403.3.2(4)

WARM-AIR FURNACES AND COMBINATION WARM-AIR FURNACES/AIR-CONDITIONING UNITS, WARM-AIR DUCT FURNACES AND UNIT HEATERS, MINIMUM EFFICIENCY REQUIREMENTS

EQUIPMENT TYPESIZE CATEGORY
(INPUT)
SUBCATEGORY OR
RATING CONDITION
MINIMUM
EFFICIENCYd, e
TEST PROCEDUREa
Warm-air furnaces,
gas fired
< 225,000 Btu/h80% AFUE or
80%Ect
DOE 10 CFR Part 430 or
ANSI Z21.47
≥ 225,000 Btu/hMaximum capacityc80%EtfANSI Z21.47
Warm-air furnaces, oil fired< 225,000 Btu/h83% AFUE or
80%Ect
DOE 10 CFR Part 430
or UL 727
≥ 225,000 Btu/hMaximum capacityb81%EtgUL 727
Warm-air duct furnaces,
gas fired
All capacitiesMaximum capacityb80%EcANSI Z83.8
Warm-air unit heaters,
gas fired
All capacitiesMaximum capacityb80%EcANSI Z83.8
Warm-air unit heaters,
oil fired
All capacitiesMaximum capacityb80%EcUL 731

For SI: 1 British thermal unit per hour = 0.2931 W.

  1. Chapter 6 contains a complete specification of the referenced test procedure, including the referenced year version of the test procedure.
  2. Minimum and maximum ratings as provided for and allowed by the unit’s controls.
  3. Combination units not covered by the National Appliance Energy Conservation Act of 1987 (NAECA) (3-phase power or cooling capacity greater than or equal to 65,000 Btu/h [19 kW]) shall comply with either rating.
  4. Et = Thermal efficiency. See test procedure for detailed discussion.
  5. Ec = Combustion efficiency (100% less flue losses). See test procedure for detailed discussion.
  6. Ec = Combustion efficiency. Units shall also include an IID, have jackets not exceeding 0.75 percent of the input rating, and have either power venting or a flue damper. A vent damper is an acceptable alternative to a flue damper for those furnaces where combustion air is drawn from the conditioned space.
  7. Et = Thermal efficiency. Units shall also include an IID, have jacket losses not exceeding 0.75 percent of the input rating, and have either power venting or a flue damper. A vent damper is an acceptable alternative to a flue damper for those furnaces where combustion air is drawn from the conditioned space.

TABLE C403.3.2(5)

MINIMUM EFFICIENCY REQUIREMENTS: GAS- AND OIL-FIRED BOILERS

EQUIPMENT TYPEaSUBCATEGORY OR
RATING CONDITION
SIZE CATEGORY (INPUT)MINIMUM EFFICIENCYd, eTEST PROCEDURE
Boilers, hot waterGas-fired< 300,000 Btu/hf, g82% AFUE10 CFR Part 430
≥ 300,000 Btu/h and
≤ 2,500,000 Btu/hb
80% Et10 CFR Part 431
> 2,500,000 Btu/ha82% Ec
Oil-firedc< 300,000 Btu/hg84% AFUE10 CFR Part 430
≥ 300,000 Btu/h and
≤ 2,500,000 Btu/hb
82% Et10 CFR Part 431
> 2,500,000 Btu/ha84% Ec
Boilers, steamGas-fired< 300,000 Btu/hf80% AFUE10 CFR Part 430
Gas-fired- all, except natural draft≥ 300,000 Btu/h and
≤ 2,500,000 Btu/hb
79% Et10 CFR Part 431
> 2,500,000 Btu/ha79% Et
Gas-fired-natural draft≥ 300,000 Btu/h and
≤ 2,500,000 Btu/hb
77% Et
> 2,500,000 Btu/ha77% Et
Oil-firedc< 300,000 Btu/h82% AFUE10 CFR Part 430
≥ 300,000 Btu/h and
≤ 2,500,000 Btu/hb
81% Et10 CFR Part 431
> 2,500,000 Btu/ha81% Et

For SI: 1 British thermal unit per hour = 0.2931 W.

  1. These requirements apply to boilers with rated input of 8,000,000 Btu/h or less that are not packaged boilers and to all packaged boilers. Minimum efficiency requirements for boilers cover all capacities of packaged boilers.
  2. Maximum capacity – minimum and maximum ratings as provided for and allowed by the unit’s controls.
  3. Includes oil-fired (residual).
  4. Ec = Combustion efficiency (100 percent less flue losses).
  5. Et = Thermal efficiency. See referenced standard for detailed information.
  6. Boilers shall not be equipped with a constant-burning ignition pilot.
  7. A boiler not equipped with a tankless domestic water heating coil shall be equipped with an automatic means for adjusting the temperature of the water such that an incremental change in inferred heat load produces a corresponding incremental change in the temperature of the water supplied.

TABLE C403.3.2(6)

MINIMUM EFFICIENCY REQUIREMENTS: CONDENSING UNITS, ELECTRICALLY OPERATED

EQUIPMENT TYPESIZE CATEGORYMINIMUM EFFICIENCYbTEST PROCEDUREa
Condensing units, air cooled≥ 135,000 Btu/h10.1 EER
11.2 IPLV
AHRI 365
Condensing units, water or evaporatively cooled≥ 135,000 Btu/h13.1 EER
13.1 IPLV

For SI: 1 British thermal unit per hour = 0.2931 W.

  1. Chapter 6 contains a complete specification of the referenced test procedure, including the referenced year version of the test procedure.
  2. IPLVs are only applicable to equipment with capacity modulation.

TABLE C403.3.2(7)

WATER CHILLING PACKAGES — EFFICIENCY REQUIREMENTSa, b, d

EQUIPMENT TYPESIZE CATEGORYUNITSBEFORE 1/1/2015AS OF 1/1/2015TEST
PROCEDUREc
Path APath BPath APath B
Air-cooled chillers< 150 TonsEER
(Btu/W)
≥ 9.562 FLNAc≥ 10.100 FL≥ 9.700 FLAHRI 550/590
≥ 12.500 IPLV≥ 13.700 IPLV≥ 15,800 IPLV
≥ 150 Tons≥ 9.562 FLNAc≥ 10.100 FL≥ 9.700 FL
≥ 12.500 IPLV≥ 14.000 IPLV≥ 16.100 IPLV
Air cooled
without condenser,
electrically operated
All capacitiesEER
(Btu/W)
Air-cooled chillers without condenser shall be rated with
matching condensers and complying with air-cooled chiller
efficiency requirements.
Water cooled, electrically
operated positive
displacement
< 75 TonskW/ton≤ 0.780 FL≤ 0.800 FL≤ 0.750 FL≤ 0.780 FL
≤ 0.630 IPLV≤ 0.600 IPLV≤ 0.600 IPLV≤ 0.500 IPLV
≥ 75 tons and < 150 tons≤ 0.775 FL≤ 0.790 FL≤ 0.720 FL≤ 0.750 FL
≤ 0.615 IPLV≤ 0.586 IPLV≤ 0.560 IPLV≤ 0.490 IPLV
≥ 150 tons and < 300 tons≥ 0.680 FL≥ 0.718 FL≥ 0.660 FL≥ 0.680 FL
≥ 0.580 IPLV≥ 0.540 IPLV≥ 0.540 IPLV≥ 0.440 IPLV
≥ 300 tons and < 600 tons≤ 0.620 FL≤ 0.639 FL≤ 0.610 FL≤ 0.625 FL
≤ 0.540 IPLV≤ 0.490 IPLV≤ 0.520 IPLV≤ 0.410 IPLV
≥ 600 tons≤ 0.620 FL≤ 0.639 FL≤ 0.560 FL≤ 0.585 FL
≤ 0.540 IPLV≤ 0.490 IPLV≤ 0.500 IPLV≤ 0.380 IPLV
Water cooled, electrically
operated centrifugal
< 150 TonskW/ton≤ 0.634 FL≤ 0.639 FL≤ 0.610 FL≤ 0.695 FL
≤ 0.596 IPLV≤ 0.450 IPLV≤ 0.550 IPLV≤ 0.440 IPLV
≥ 150 tons and < 300 tons≤ 0.634 FL≤ 0.639 FL≤ 0.610 FL≤ 0.635 FL
≤ 0.596 IPLV≤ 0.450 IPLV≤ 0.550 IPLV≤ 0.400 IPLV
≥ 300 tons and < 400 tons≤ 0.576 FL≤ 0.600 FL≤ 0.560 FL≤ 0.595 FL
≤ 0.549 IPLV≤ 0.400 IPLV≤ 0.520 IPLV≤ 0.390 IPLV
≥ 400 tons and < 600 tons≤ 0.576 FL≤ 0.600 FL≤ 0.560 FL≤ 0.585 FL
≤ 0.549 IPLV≤ 0.400 IPLV≤ 0.500 IPLV≤ 0.380 IPLV
≥ 600 Tons≤ 0.570 FL≤ 0.590 FL≤ 0.560 FL≤ 0.585 FL
≤ 0.539 IPLV≤ 0.400 IPLV≤ 0.500 IPLV≤ 0.380 IPLV
Air cooled, absorption,
single effect
All capacitiesCOP≥ 0.600 FLNAc≥ 0.600 FLNAcAHRI 560
Water cooled absorption,
single effect
All capacitiesCOP≥ 0.700 FLNAc≥ 0.700 FLNAc
Absorption, double
effect, indirect fired
All capacitiesCOP≥ 1.000 FLNAc≥ 1.000 FLNAc
≥ 1.050 IPLV≥ 1.050 IPLV
Absorption double effect
direct fired
All capacitiesCOP≥ 1.000 FLNAc≥ 1.000 FLNAc
≥ 1.000 IPLV≥ 1.050 IPLV
  1. The requirements for centrifugal chiller shall be adjusted for nonstandard rating conditions in accordance with Section C403.3.2.1 and are only applicable for the range of conditions listed in Section C403.3.2.1. The requirements for air-cooled, water-cooled positive displacement and absorption chillers are at standard rating conditions defined in the reference test procedure.
  2. Both the full-load and IPLV requirements shall be met or exceeded to comply with this standard. Where there is a Path B, compliance can be with either Path A or Path B for any application.
  3. NA means the requirements are not applicable for Path B and only Path A can be used for compliance.
  4. FL represents the full-load performance requirements and IPLV the part-load performance requirements.

TABLE C403.3.2(8)

MINIMUM EFFICIENCY REQUIREMENTS: HEAT REJECTION EQUIPMENT

EQUIPMENT TYPEaTOTAL SYSTEM
HEAT REJECTION
CAPACITY AT RATED
CONDITIONS
SUBCATEGORY OR RATING CONDITIONiPERFORMANCE
REQUIREDb, c, d, g, h
TEST PROCEDUREe, f
Propeller or axial fan
open-circuit cooling towers
All95°F entering water
85°F leaving water
75°F entering wb
≥ 40.2 gpm/hpCTI ATC-105 and
CTI STD-201 RS
Centrifugal fan
open-circuit cooling towers
All95°F entering water
85°F leaving water
75°F entering wb
≥ 20.0 gpm/hpCTI ATC-105 and
CTI STD-201 RS
Propeller or axial fan
closed-circuit cooling
towers
All102°F entering water
90°F leaving water
75°F entering wb
≥ 16.1 gpm/hpCTI ATC-105S and
CTI STD-201 RS
Centrifugal fan closed-
circuit cooling towers
All102°F entering water
90°F leaving water
75°F entering wb
≥ 7.0 gpm/hpCTI ATC-105S and
CTI STD-201 RS
Propeller or axial fan
evaporative condensers
AllAmmonia Test Fluid
140°F entering gas temperature
96.3°F condensing temperature
75°F entering wb
≥ 134,000 Btu/h × hpCTI ATC-106
Centrifugal fan
evaporative condensers
AllAmmonia Test Fluid
140°F entering gas temperature
96.3°F condensing temperature
75°F entering wb
≥ 110,000 Btu/h × hpCTI ATC-106
Propeller or axial fan
evaporative condensers
AllR-507A Test Fluid
165°F entering gas temperature
105°F condensing temperature
75°F entering wb
≥ 157,000 Btu/h × hpCTI ATC-106
Centrifugal fan
evaporative condensers
AllR-507A Test Fluid
165°F entering gas temperature
105°F condensing temperature
75°F entering wb
≥ 135,000 Btu/h × hpCTI ATC-106
Air-cooled condensersAll125°F Condensing Temperature
190°F Entering Gas Temperature
15°F subcooling 95°F entering db
≥ 176,000 Btu/h × hpAHRI 460

For SI: °C = [(°F)-32]/1.8, L/s • kW = (gpm/hp)/(11.83), COP = (Btu/h • hp)/(2550.7),

db = dry bulb temperature, °F, wb = wet bulb temperature, °F.

  1. The efficiencies and test procedures for both open- and closed-circuit cooling towers are not applicable to hybrid cooling towers that contain a combination of wet and dry heat exchange sections.
  2. For purposes of this table, open circuit cooling tower performance is defined as the water flow rating of the tower at the thermal rating condition, divided by the fan nameplate-rated motor power.
  3. For purposes of this table, closed-circuit cooling tower performance is defined as the water flow rating of the tower at the thermal rating condition, divided by the sum of the fan nameplate-rated motor power and the spray pump nameplate-rated motor power.
  4. For purposes of this table, air-cooled condenser performance is defined as the heat rejected from the refrigerant divided by the fan nameplate-rated motor power.
  5. Chapter 6 contains a complete specification of the referenced test procedure, including the referenced year version of the test procedure. The certification requirements do not apply to field-erected cooling towers.
  6. Where a certification program exists for a covered product and it includes provisions for verification and challenge of equipment efficiency ratings, then the product shall be listed in the certification program; or, where a certification program exists for a covered product, and it includes provisions for verification and challenge of equipment efficiency ratings, but the product is not listed in the existing certification program, the ratings shall be verified by an independent laboratory test report.
  7. Cooling towers shall comply with the minimum efficiency listed in the table for that specific type of tower with the capacity effect of any project-specific accessories or options included in the capacity of the cooling tower
  8. For purposes of this table, evaporative condenser performance is defined as the heat rejected at the specified rating condition in the table divided by the sum of the fan motor nameplate power and the integral spray pump nameplate power
  9. Requirements for evaporative condensers are listed with ammonia (R-717) and R-507A as test fluids in the table. Evaporative condensers intended for use with halocarbon refrigerants other than R-507A shall meet the minimum efficiency requirements listed in this table with R-507A as the test fluid.

TABLE C403.3.2(9)

MINIMUM EFFICIENCY AIR CONDITIONERS AND CONDENSING UNITS SERVING COMPUTER ROOMS

EQUIPMENT TYPENET SENSIBLE COOLING CAPACITYaMINIMUM SCOP-127b EFFICIENCY
DOWNFLOW UNITS / UPFLOW UNITS
TEST PROCEDURE
Air conditioners, air cooled< 65,000 Btu/h2.20 / 2.09ANSI/ASHRAE 127
≥ 65,000 Btu/h and < 240,000 Btu/h2.10 / 1.99
≥ 240,000 Btu/h1.90 / 1.79
Air conditioners, water cooled< 65,000 Btu/h2.60 / 2.49
≥ 65,000 Btu/h and < 240,000 Btu/h2.50 / 2.39
≥ 240,000 Btu/h2.40 / 2.29
Air conditioners, water cooled with
fluid economizer
< 65,000 Btu/h2.55 / 2.44
≥ 65,000 Btu/h and < 240,000 Btu/h2.45 / 2.34
≥ 240,000 Btu/h2.35 / 2.24
Air conditioners, glycol cooled
(rated at 40% propylene glycol)
< 65,000 Btu/h2.50 / 2.39
≥ 65,000 Btu/h and < 240,000 Btu/h2.15 / 2.04
≥ 240,000 Btu/h2.10 / 1.99
Air conditioners, glycol cooled
(rated at 40% propylene glycol)
with fluid economizer
< 65,000 Btu/h2.45 / 2.34
≥ 65,000 Btu/h and < 240,000 Btu/h2.10 / 1.99
≥ 240,000 Btu/h2.05 / 1.94

For SI: 1 British thermal unit per hour = 0.2931 W.

  1. Net sensible cooling capacity: the total gross cooling capacity less the latent cooling less the energy to the air movement system. (Total Gross – latent – Fan Power).
  2. Sensible coefficient of performance (SCOP-127): a ratio calculated by dividing the net sensible cooling capacity in watts by the total power input in watts (excluding reheaters and humidifiers) at conditions defined in ASHRAE Standard 127. The net sensible cooling capacity is the gross sensible capacity minus the energy dissipated into the cooled space by the fan system.

TABLE C403.3.2(10)

HEAT TRANSFER EQUIPMENT

EQUIPMENT TYPESUBCATEGORYMINIMUM EFFICIENCYTEST PROCEDUREa
Liquid-to-liquid heat exchangersPlate typeNRAHRI 400

NR = No Requirement.

  1. Chapter 6 contains a complete specification of the referenced test procedure, including the referenced year version of the test procedure.

Equipment not designed for operation at AHRI Standard 550/590 test conditions of 44°F (7°C) leaving chilled-water temperature and 2.4 gpm/ton evaporator fluid flow and 85°F (29°C) entering condenser water temperature with 3 gpm/ton (0.054 I/s • kW) condenser water flow shall have maximum full-load kW/ton (FL) and part-load ratings requirements adjusted using Equations 4-6 and 4-7.

(Equation 4-6)

(Equation 4-7)

where:

Kadj = A x B

FL = Full-load kW/ton value as specified in Table C403.3.2(7).

FLadj = Maximum full-load kW/ton rating, adjusted for nonstandard conditions.

IPLV = Value as specified in Table C403.3.2(7).

PLVadj = Maximum NPLV rating, adjusted for nonstandard conditions.

A = 0.00000014592 × (LIFT)4 - 0.0000346496 × (LIFT)3 + 0.00314196 × (LIFT)2 - 0.147199 × (LIFT) + 3.9302

B = 0.0015 × LvgEvap + 0.934

LIFT = LvgCond - LvgEvap

LvgCond = Full-load condenser leaving fluid temperature (°F).

LvgEvap = Full-load evaporator leaving temperature (°F).

The FLadj and PLVadj values are only applicable for centrifugal chillers meeting all of the following full-load design ranges:

  1. Minimum evaporator leaving temperature: 36°F.
  2. Maximum condenser leaving temperature: 115°F.
  3. 20°F ≤ LIFT ≤ 80°F.
Equipment with a leaving fluid temperature higher than 32°F (0°C) and water-cooled positive displacement chilling packages with a condenser leaving fluid temperature below 115°F (46°C) shall meet the requirements of Table C403.3.2(7) when tested or certified with water at standard rating conditions, in accordance with the referenced test procedure.

Cooling systems shall not use hot gas bypass or other evaporator pressure control systems unless the system is designed with multiple steps of unloading or continuous capacity modulation. The capacity of the hot gas bypass shall be limited as indicated in Table C403.3.3, as limited by Section C403.5.1.

TABLE C403.3.3

MAXIMUM HOT GAS BYPASS CAPACITY

RATED CAPACITYMAXIMUM HOT GAS BYPASS CAPACITY
(% of total capacity)
≤ 240,000 Btu/h50
> 240,000 Btu/h25

For SI: 1 British thermal unit per hour = 0.2931 W.

Boiler systems with design input of greater than 1,000,000 Btu/h (293 kW) shall comply with the turndown ratio specified in Table C403.3.4.

The system turndown requirement shall be met through the use of multiple single-input boilers, one or more modulating boilers or a combination of single-input and modulating boilers.

TABLE C403.3.4

BOILER TURNDOWN

BOILER SYSTEM DESIGN INPUT (Btu/h)MINIMUM
TURNDOWN
RATIO
≥ 1,000,000 and less than or equal to 5,000,0003 to 1
> 5,000,000 and less than or equal to 10,000,0004 to 1
> 10,000,0005 to 1

For SI: 1 British thermal unit per hour = 0.2931 W.

Each heating and cooling system shall be provided with controls in accordance with Sections C403.4.1 through C403.4.5.

The supply of heating and cooling energy to each zone shall be controlled by individual thermostatic controls capable of responding to temperature within the zone. Where humidification or dehumidification or both is provided, not fewer than one humidity control device shall be provided for each humidity control system.

Exception: Independent perimeter systems that are designed to offset only building envelope heat losses, gains or both serving one or more perimeter zones also served by an interior system provided that both of the following conditions are met:

  1. The perimeter system includes not fewer than one thermostatic control zone for each building exposure having exterior walls facing only one orientation (within ± 45 degrees) (0.8 rad) for more than 50 contiguous feet (15 240 mm).
  2. The perimeter system heating and cooling supply is controlled by thermostats located within the zones served by the system.
Heat pumps having supplementary electric resistance heat shall have controls that, except during defrost, prevent supplementary heat operation where the heat pump can provide the heating load.

Where used to control both heating and cooling, zone thermostatic controls shall be configured to provide a temperature range or deadband of not less than 5°F (2.8°C) within which the supply of heating and cooling energy to the zone is shut off or reduced to a minimum.

Exceptions:

  1. Thermostats requiring manual changeover between heating and cooling modes.
  2. Occupancies or applications requiring precision in indoor temperature control as approved by the code official.
Where a zone has a separate heating and a separate cooling thermostatic control located within the zone, a limit switch, mechanical stop or direct digital control system with software programming shall be configured to prevent the heating setpoint from exceeding the cooling setpoint and to maintain a deadband in accordance with Section C403.4.1.2.

The heating system for heated vestibules and air curtains with integral heating shall be provided with controls configured to shut off the source of heating when the outdoor air temperature is greater than 45°F (7°C). Vestibule heating and cooling systems shall be controlled by a thermostat located in the vestibule configured to limit heating to a temperature not greater than 60°F (16°C) and cooling to a temperature not less than 85°F (29°C).

Exception: Control of heating or cooling provided by site-recovered energy or transfer air that would otherwise be exhausted.

Hot water boilers that supply heat to the building through one- or two-pipe heating systems shall have an outdoor setback control that lowers the boiler water temperature based on the outdoor temperature.

Each zone shall be provided with thermostatic setback controls that are controlled by either an automatic time clock or programmable control system.

Exceptions:

  1. Zones that will be operated continuously.
  2. Zones with a full HVAC load demand not exceeding 6,800 Btu/h (2 kW) and having a manual shutoff switch located with ready access.
Thermostatic setback controls shall be configured to set back or temporarily operate the system to maintain zone temperatures down to 55°F (13°C) or up to 85°F (29°C).
Automatic time clock or programmable controls shall be capable of starting and stopping the system for seven different daily schedules per week and retaining their programming and time setting during a loss of power for not fewer than 10 hours. Additionally, the controls shall have a manual override that allows temporary operation of the system for up to 2 hours; a manually operated timer configured to operate the system for up to 2 hours; or an occupancy sensor.
Automatic start controls shall be provided for each HVAC system. The controls shall be configured to automatically adjust the daily start time of the HVAC system in order to bring each space to the desired occupied temperature immediately prior to scheduled occupancy.
The heating of fluids that have been previously mechanically cooled and the cooling of fluids that have been previously mechanically heated shall be limited in accordance with Sections C403.4.3.1 through C403.4.3.3. Hydronic heating systems comprised of multiple-packaged boilers and designed to deliver conditioned water or steam into a common distribution system shall include automatic controls configured to sequence operation of the boilers. Hydronic heating systems composed of a single boiler and greater than 500,000 Btu/h (146.5 kW) input design capacity shall include either a multistaged or modulating burner.
Hydronic systems that use a common return system for both hot water and chilled water are prohibited.
Systems that use a common distribution system to supply both heated and chilled water shall be designed to allow a deadband between changeover from one mode to the other of not less than 15°F (8.3°C) outside air temperatures; be designed to and provided with controls that will allow operation in one mode for not less than 4 hours before changing over to the other mode; and be provided with controls that allow heating and cooling supply temperatures at the changeover point to be not more than 30°F (16.7°C) apart.
Hydronic heat pump systems shall comply with Sections C403.4.3.3.1 through C403.4.3.3.3.

Hydronic heat pumps connected to a common heat pump water loop with central devices for heat rejection and heat addition shall have controls that are configured to provide a heat pump water supply temperature deadband of not less than 20°F (11°C) between initiation of heat rejection and heat addition by the central devices.

Exception: Where a system loop temperature optimization controller is installed and can determine the most efficient operating temperature based on real-time conditions of demand and capacity, deadbands of less than 20°F (11°C) shall be permitted.

The following shall apply to hydronic water loop heat pump systems in Climate Zones 3 through 8:

  1. Where a closed-circuit cooling tower is used directly in the heat pump loop, either an automatic valve shall be installed to bypass the flow of water around the closed-circuit cooling tower, except for any flow necessary for freeze protection, or low-leakage positive-closure dampers shall be provided.
  2. Where an open-circuit cooling tower is used directly in the heat pump loop, an automatic valve shall be installed to bypass all heat pump water flow around the open-circuit cooling tower.
  3. Where an open-circuit cooling tower is used in conjunction with a separate heat exchanger to isolate the open-circuit cooling tower from the heat pump loop, heat loss shall be controlled by shutting down the circulation pump on the cooling tower loop.

Exception: Where it can be demonstrated that a heat pump system will be required to reject heat throughout the year.

Each hydronic heat pump on the hydronic system having a total pump system power exceeding 10 hp (7.5 kW) shall have a two-position valve.

Hydronic systems greater than or equal to 300,000 Btu/h (146.5 kW) in design output capacity supplying heated or chilled water to comfort conditioning systems shall include controls that are configured to do all of the following:

  1. Automatically reset the supply-water temperatures in response to varying building heating and cooling demand using coil valve position, zone-return water temperature, building-return water temperature or outside air temperature. The temperature shall be reset by not less than 25 percent of the design supply-to-return water temperature difference.
  2. Automatically vary fluid flow for hydronic systems with a combined pump motor capacity of 2 hp (1.5 kW) or larger with three or more control valves or other devices by reducing the system design flow rate by not less than 50 percent or the maximum reduction allowed by the equipment manufacturer for proper operation of equipment by valves that modulate or step open and close, or pumps that modulate or turn on and off as a function of load.
  3. Automatically vary pump flow on heating-water systems, chilled-water systems and heat rejection loops serving water-cooled unitary air conditioners as follows:

    1. 3.1. Where pumps operate continuously or operate based on a time schedule, pumps with nominal output motor power of 2 hp or more shall have a variable speed drive.
    2. 3.2. Where pumps have automatic direct digital control configured to operate pumps only when zone heating or cooling is required, a variable speed drive shall be provided for pumps with motors having the same or greater nominal output power indicated in Table C403.4.4 based on the climate zone and system served.
  4. Where a variable speed drive is required by Item 3 of this Section, pump motor power input shall be not more than 30 percent of design wattage at 50 percent of the design water flow. Pump flow shall be controlled to maintain one control valve nearly wide open or to satisfy the minimum differential pressure.

Exceptions:

  1. Supply-water temperature reset is not required for chilled-water systems supplied by off-site district chilled water or chilled water from ice storage systems.
  2. Variable pump flow is not required on dedicated coil circulation pumps where needed for freeze protection.
  3. Variable pump flow is not required on dedicated equipment circulation pumps where configured in primary/secondary design to provide the minimum flow requirements of the equipment manufacturer for proper operation of equipment.
  4. Variable speed drives are not required on heating water pumps where more than 50 percent of annual heat is generated by an electric boiler.

TABLE C403.4.4

VARIABLE SPEED DRIVE (VSD) REQUIREMENTS FOR DEMAND-CONTROLLED PUMPS

CHILLED WATER AND HEAT REJECTION LOOP
PUMPS IN THESE CLIMATE ZONES
HEATING WATER PUMPS IN THESE CLIMATE ZONESVSD REQUIRED FOR MOTORS WITH
RATED OUTPUT OF:
1A, 1B, 2B≥ 2 hp
2A, 3B≥ 3 hp
3A, 3C, 4A, 4B7, 8≥ 5 hp
4C, 5A, 5B, 5C, 6A, 6B3C, 5A, 5C, 6A, 6B≥ 7.5 hp
4A, 4C, 5B≥ 10 hp
7, 84B≥ 15 hp
2A, 2B, 3A, 3B≥ 25 hp
1B≥ 100 hp
1A≥ 200 hp

Chilled water plants including more than one chiller shall be capable of and configured to reduce flow automatically through the chiller plant when a chiller is shut down. Chillers piped in series for the purpose of increased temperature differential shall be considered as one chiller.

Boiler systems including more than one boiler shall be capable of and configured to reduce flow automatically through the boiler system when a boiler is shut down.

Economizers shall comply with Sections C403.5.1 through C403.5.5.

An air or water economizer shall be provided for the following cooling systems:

  1. Chilled water systems with a total cooling capacity, less cooling capacity provided with air economizers, as specified in Table C403.5(1).
  2. Individual fan systems with cooling capacity greater than or equal to 54,000 Btu/h (15.8 kW) in buildings having other than a Group R occupancy,

    The total supply capacity of all fan cooling units not provided with economizers shall not exceed 20 percent of the total supply capacity of all fan cooling units in the building or 300,000 Btu/h (88 kW), whichever is greater.

  3. Individual fan systems with cooling capacity greater than or equal to 270,000 Btu/h (79.1 kW) in buildings having a Group R occupancy.

    The total supply capacity of all fan cooling units not provided with economizers shall not exceed 20 percent of the total supply capacity of all fan cooling units in the building or 1,500,000 Btu/h (440 kW), whichever is greater.

Exceptions: Economizers are not required for the following systems.

  1. Individual fan systems not served by chilled water for buildings located in Climate Zones 1A and 1B.
  2. Where more than 25 percent of the air designed to be supplied by the system is to spaces that are designed to be humidified above 35°F (1.7°C) dew-point temperature to satisfy process needs.
  3. Systems expected to operate less than 20 hours per week.
  4. Systems serving supermarket areas with open refrigerated casework.
  5. Where the cooling efficiency is greater than or equal to the efficiency requirements in Table C403.5(2).
  6. Systems that include a heat recovery system in accordance with Section C403.9.5.

TABLE C403.5(1)

MINIMUM CHILLED-WATER SYSTEM COOLING CAPACITY FOR DETERMINING ECONOMIZER COOLING REQUIREMENTS

CLIMATE ZONES
(COOLING)
TOTAL CHILLED-WATER SYSTEM CAPACITY LESS CAPACITY OF COOLING UNITS WITH AIR ECONOMIZERS
Local Water-cooled Chilled-water SystemsAir-cooled Chilled-water Systems or District Chilled-Water Systems
1AEconomizer not requiredEconomizer not required
1B, 2A, 2B960,000 Btu/h1,250,000 Btu/h
3A, 3B, 3C, 4A, 4B, 4C720,000 Btu/h940,000 Btu/h
5A, 5B, 5C, 6A, 6B, 7, 81,320,000 Btu/h1,720,000 Btu/h

For SI: 1 British thermal unit per hour = 0.2931 W.

TABLE C403.5(2)

EQUIPMENT EFFICIENCY PERFORMANCE EXCEPTION FOR ECONOMIZERS

CLIMATE
ZONES
COOLING EQUIPMENT PERFORMANCE
IMPROVEMENT (EER OR IPLV)
2A, 2B10% efficiency improvement
3A, 3B15% efficiency improvement
4A, 4B20% efficiency improvement

Economizer systems shall be integrated with the mechanical cooling system and be configured to provide partial cooling even where additional mechanical cooling is required to provide the remainder of the cooling load. Controls shall not be capable of creating a false load in the mechanical cooling systems by limiting or disabling the economizer or any other means, such as hot gas bypass, except at the lowest stage of mechanical cooling.

Units that include an air economizer shall comply with the following:

  1. Unit controls shall have the mechanical cooling capacity control interlocked with the air economizer controls such that the outdoor air damper is at the 100-percent open position when mechanical cooling is on and the outdoor air damper does not begin to close to prevent coil freezing due to minimum compressor run time until the leaving air temperature is less than 45°F (7°C).
  2. Direct expansion (DX) units that control 75,000 Btu/h (22 kW) or greater of rated capacity of the capacity of the mechanical cooling directly based on occupied space temperature shall have not fewer than two stages of mechanical cooling capacity.
  3. Other DX units, including those that control space temperature by modulating the airflow to the space, shall be in accordance with Table C403.5.1.

TABLE C403.5.1

DX COOLING STAGE REQUIREMENTS FOR MODULATING AIRFLOW UNITS

RATING CAPACITYMINIMUM NUMBER
OF MECHANICAL COOLING STAGES
MINIMUM
COMPRESSOR DISPLACEMENTa
≥ 65,000 Btu/h and < 240,000 Btu/h3 stages≤ 35% of full load
≥ 240,000 Btu/h4 stages≤ 25% full load

For SI: 1 British thermal unit per hour = 0.2931 W.

  1. For mechanical cooling stage control that does not use variable compressor displacement, the percent displacement shall be equivalent to the mechanical cooling capacity reduction evaluated at the full load rating conditions for the compressor.

HVAC system design and economizer controls shall be such that economizer operation does not increase building heating energy use during normal operation.

Exception: Economizers on variable air volume (VAV) systems that cause zone level heating to increase because of a reduction in supply air temperature.

Where economizers are required by Section C403.5, air economizers shall comply with Sections C403.5.3.1 through C403.5.3.5.
Air economizer systems shall be configured to modulate outdoor air and return air dampers to provide up to 100 percent of the design supply air quantity as outdoor air for cooling.

Economizer controls and dampers shall be configured to sequence the dampers with the mechanical cooling equipment and shall not be controlled by only mixed-air temperature.

Exception: The use of mixed-air temperature limit control shall be permitted for systems controlled from space temperature (such as single-zone systems).

Air economizers shall be configured to automatically reduce outdoor air intake to the design minimum outdoor air quantity when outdoor air intake will not reduce cooling energy usage. High-limit shutoff control types for specific climates shall be chosen from Table C403.5.3.3. High-limit shutoff control settings for these control types shall be those specified in Table C403.5.3.3.

TABLE C403.5.3.3

HIGH-LIMIT SHUTOFF CONTROL SETTING FOR AIR ECONOMIZERSb

DEVICE TYPECLIMATE ZONEREQUIRED HIGH LIMIT
(ECONOMIZER OFF WHEN):
EquationDescription
Fixed dry bulb1B, 2B, 3B, 3C, 4B, 4C,
5B, 5C, 6B, 7, 8
TOA > 75°FOutdoor air temperature exceeds 75°F
5A, 6ATOA > 70°FOutdoor air temperature exceeds 70°F
1A, 2A, 3A, 4ATOA > 65°FOutdoor air temperature exceeds 65°F
Differential dry bulb1B, 2B, 3B, 3C, 4B, 4C, 5A,
5B, 5C, 6A, 6B, 7, 8
TOA > TRAOutdoor air temperature exceeds
return air temperature
Fixed enthalpy with fixed
dry-bulb temperatures
AllhOA > 28 Btu/lba or
TOA > 75°F
Outdoor air enthalpy exceeds
28 Btu/lb of dry aira or
Outdoor air temperature exceeds 75°F
Differential enthalpy with
fixed dry-bulb temperature
AllhOA > hRA or
TOA > 75°F
Outdoor air enthalpy exceeds
return air enthalpy or
Outdoor air temperature exceeds 75°F

For SI: 1 foot = 305 mm, °C = (°F - 32)/1.8, 1 Btu/lb = 2.33 kJ/kg.

  1. At altitudes substantially different than sea level, the fixed enthalpy limit shall be set to the enthalpy value at 75°F and 50-percent relative humidity. As an example, at approximately 6,000 feet elevation, the fixed enthalpy limit is approximately 30.7 Btu/lb.
  2. Devices with selectable setpoints shall be capable of being set to within 2°F and 2 Btu/lb of the setpoint listed.
Systems shall be capable of relieving excess outdoor air during air economizer operation to prevent overpressurizing the building. The relief air outlet shall be located to avoid recirculation into the building.
Return, exhaust/relief and outdoor air dampers used in economizers shall comply with Section C403.7.7.
Where economizers are required by Section C403.5, water-side economizers shall comply with Sections C403.5.4.1 and C403.5.4.2.

Water economizer systems shall be configured to cool supply air by indirect evaporation and providing up to 100 percent of the expected system cooling load at outdoor air temperatures of not greater than 50°F (10°C) dry bulb/45°F (7°C) wet bulb.

Exceptions:

  1. Systems primarily serving computer rooms in which 100 percent of the expected system cooling load at 40°F (4°C) dry bulb/35°F (1.7°C) wet bulb is met with evaporative water economizers.
  2. Systems primarily serving computer rooms with dry cooler water economizers that satisfy 100 percent of the expected system cooling load at 35°F (1.7°C) dry bulb.
  3. Systems where dehumidification requirements cannot be met using outdoor air temperatures of 50°F (10°C) dry bulb/45°F (7°C) wet bulb and where 100 percent of the expected system cooling load at 45°F (7°C) dry bulb/40°F (4°C) wet bulb is met with evaporative water economizers.
Precooling coils and water-to-water heat exchangers used as part of a water economizer system shall either have a water-side pressure drop of less than 15 feet (45 kPa) of water or a secondary loop shall be created so that the coil or heat exchanger pressure drop is not seen by the circulating pumps when the system is in the normal cooling (noneconomizer) mode.

Air-cooled unitary direct-expansion units listed in Tables C403.3.2(1) through C403.3.2(3) and variable refrigerant flow (VRF) units that are equipped with an economizer in accordance with Sections C403.5 through C403.5.4 shall include a fault detection and diagnostics system complying with the following:

  1. The following temperature sensors shall be permanently installed to monitor system operation:

    1. 1.1. Outside air.
    2. 1.2. Supply air.
    3. 1.3. Return air.
  2. Temperature sensors shall have an accuracy of ±2°F (1.1°C) over the range of 40°F to 80°F (4°C to 26.7°C).
  3. Refrigerant pressure sensors, where used, shall have an accuracy of ±3 percent of full scale.
  4. The unit controller shall be configured to provide system status by indicating the following:

    1. 4.1. Free cooling available.
    2. 4.2. Economizer enabled.
    3. 4.3. Compressor enabled.
    4. 4.4. Heating enabled.
    5. 4.5. Mixed air low limit cycle active.
    6. 4.6. The current value of each sensor.
  5. The unit controller shall be capable of manually initiating each operating mode so that the operation of compressors, economizers, fans and the heating system can be independently tested and verified.
  6. The unit shall be configured to report faults to a fault management application available for access by day-to-day operating or service personnel, or annunciated locally on zone thermostats.
  7. The fault detection and diagnostics system shall be configured to detect the following faults:

    1. 7.1. Air temperature sensor failure/fault.
    2. 7.2. Not economizing when the unit should be economizing.
    3. 7.3. Economizing when the unit should not be economizing.
    4. 7.4. Damper not modulating.
    5. 7.5. Excess outdoor air.
Sections C403.6.1 through C403.6.9 shall apply to mechanical systems serving multiple zones.

Supply air systems serving multiple zones shall be variable air volume (VAV) systems that have zone controls configured to reduce the volume of air that is reheated, recooled or mixed in each zone to one of the following:

  1. Twenty percent of the zone design peak supply for systems with DDC and 30 percent for other systems.
  2. Systems with DDC where all of the following apply:

    1. 2.1. The airflow rate in the deadband between heating and cooling does not exceed 20 percent of the zone design peak supply rate or higher allowed rates under Items 3, 4 and 5 of this section.
    2. 2.2. The first stage of heating modulates the zone supply air temperature setpoint up to a maximum setpoint while the airflow is maintained at the deadband flow rate.
    3. 2.3. The second stage of heating modulates the airflow rate from the deadband flow rate up to the heating maximum flow rate that is less than 50 percent of the zone design peak supply rate.
  3. The outdoor airflow rate required to meet the minimum ventilation requirements of Chapter 4 of the International Mechanical Code.
  4. Any higher rate that can be demonstrated to reduce overall system annual energy use by offsetting re-heat/recool energy losses through a reduction in outdoor air intake for the system as approved by the code official.
  5. The airflow rate required to comply with applicable codes or accreditation standards such as pressure relationships or minimum air change rates.

Exception: The following individual zones or entire air distribution systems are exempted from the requirement for VAV control:

  1. Zones or supply air systems where not less than 75 percent of the energy for reheating or for providing warm air in mixing systems is provided from a site-recovered, including condenser heat, or site-solar energy source.
  2. Systems that prevent reheating, recooling, mixing or simultaneous supply of air that has been previously cooled, either mechanically or through the use of economizer systems, and air that has been previously mechanically heated.
Single-duct VAV systems shall use terminal devices capable of and configured to reduce the supply of primary supply air before reheating or recooling takes place.
Systems that have one warm air duct and one cool air duct shall use terminal devices that are configured to reduce the flow from one duct to a minimum before mixing of air from the other duct takes place.
Individual dual-duct or mixing heat-ing and cooling systems with a single fan and with total capacities greater than 90,000 Btu/h [(26.4 kW) 7.5 tons] shall not be equipped with air economizers.

Multiple-zone HVAC systems shall include controls that automatically reset the supply-air temperature in response to representative building loads, or to outdoor air temperature. The controls shall be configured to reset the supply air temperature not less than 25 percent of the difference between the design supply-air temperature and the design room air temperature.

Exceptions:

  1. Systems that prevent reheating, recooling or mixing of heated and cooled supply air.
  2. Seventy-five percent of the energy for reheating is from site-recovered or site-solar energy sources.
  3. Zones with peak supply air quantities of 300 cfm (142 L/s) or less.

Multiple-zone VAV systems with direct digital control of individual zone boxes reporting to a central control panel shall have automatic controls configured to reduce outdoor air intake flow below design rates in response to changes in system ventilation efficiency (Ev) as defined by the International Mechanical Code.

Exceptions:

  1. VAV systems with zonal transfer fans that recirculate air from other zones without directly mixing it with outdoor air, dual-duct dual-fan VAV systems, and VAV systems with fan-powered terminal units.
  2. Systems where total design exhaust airflow is more than 70 percent of total design outdoor air intake flow requirements.

Parallel-flow fan-powered VAV air terminals shall have automatic controls configured to:

  1. Turn off the terminal fan except when space heating is required or where required for ventilation.
  2. Turn on the terminal fan as the first stage of heating before the heating coil is activated.
  3. During heating for warmup or setback temperature control, either:

    1. 3.1. Operate the terminal fan and heating coil without primary air.
    2. 3.2. Reverse the terminal damper logic and provide heating from the central air handler by primary air.

For systems with direct digital control of individual zones reporting to the central control panel, the static pressure setpoint shall be reset based on the zone requiring the most pressure. In such case, the setpoint is reset lower until one zone damper is nearly wide open. The direct digital controls shall be capable of monitoring zone damper positions or shall have an alternative method of indicating the need for static pressure that is configured to provide all of the following:

  1. Automatic detection of any zone that excessively drives the reset logic.
  2. Generation of an alarm to the system operational location.
  3. Allowance for an operator to readily remove one or more zones from the reset algorithm.
Static pressure sensors used to control VAV fans shall be located such that the controller setpoint is not greater than 1.2 inches w.c. (299 Pa). Where this results in one or more sensors being located downstream of major duct splits, not less than one sensor shall be located on each major branch to ensure that static pressure can be maintained in each branch.
In addition to other requirements of Section C403 applicable to the provision of ventilation air or the exhaust of air, ventilation and exhaust systems shall be in accordance with Sections C403.7.1 through C403.7.7.

Demand control ventilation (DCV) shall be provided for spaces larger than 500 square feet (46.5 m2) and with an average occupant load of 25 people or greater per 1,000 square feet (93 m2) of floor area, as established in Table 403.3.1.1 of the International Mechanical Code, and served by systems with one or more of the following:

  1. An air-side economizer.
  2. Automatic modulating control of the outdoor air damper.
  3. A design outdoor airflow greater than 3,000 cfm (1416 L/s).

Exceptions:

  1. Systems with energy recovery complying with Section C403.7.4.
  2. Multiple-zone systems without direct digital control of individual zones communicating with a central control panel.
  3. Systems with a design outdoor airflow less than 1,200 cfm (566 L/s).
  4. Spaces where the supply airflow rate minus any makeup or outgoing transfer air requirement is less than 1,200 cfm (566 L/s).
  5. Ventilation provided only for process loads.

Enclosed parking garages used for storing or handling automobiles operating under their own power shall employ contamination-sensing devices and automatic controls configured to stage fans or modulate fan average airflow rates to 50 percent or less of design capacity, or intermittently operate fans less than 20 percent of the occupied time or as required to maintain acceptable contaminant levels in accordance with International Mechanical Code provisions. Failure of contamination-sensing devices shall cause the exhaust fans to operate continuously at design airflow.

Exceptions:

  1. Garages with a total exhaust capacity less than 22,500 cfm (10 620 L/s) with ventilation systems that do not utilize heating or mechanical cooling.
  2. Garages that have a garage area to ventilation system motor nameplate power ratio that exceeds 1125 cfm/hp (710 L/s/kW) and do not utilize heating or mechanical cooling.
Units that provide ventilation air to multiple zones and operate in conjunction with zone heating and cooling systems shall not use heating or heat recovery to warm supply air to a temperature greater than 60°F (16°C) when representative building loads or outdoor air temperatures indicate that the majority of zones require cooling.

Where the supply airflow rate of a fan system exceeds the values specified in Tables C403.7.4(1) and C403.7.4(2), the system shall include an energy recovery system. The energy recovery system shall be configured to provide a change in the enthalpy of the outdoor air supply of not less than 50 percent of the difference between the outdoor air and return air enthalpies, at design conditions. Where an air economizer is required, the energy recovery system shall include a bypass or controls that permit operation of the economizer as required by Section C403.5.

Exception: An energy recovery ventilation system shall not be required in any of the following conditions:

  1. Where energy recovery systems are prohibited by the International Mechanical Code.
  2. Laboratory fume hood systems that include not fewer than one of the following features:

    1. 2.1. Variable-air-volume hood exhaust and room supply systems configured to reduce exhaust and makeup air volume to 50 percent or less of design values.
    2. 2.2. Direct makeup (auxiliary) air supply equal to or greater than 75 percent of the exhaust rate, heated not warmer than 2°F (1.1°C) above room setpoint, cooled to not cooler than 3°F (1.7°C) below room setpoint, with no humidification added, and no simultaneous heating and cooling used for dehumidification control.
  3. Systems serving spaces that are heated to less than 60°F (15.5°C) and that are not cooled.
  4. Where more than 60 percent of the outdoor heating energy is provided from site-recovered or site-solar energy.
  5. Heating energy recovery in Climate Zones 1 and 2.
  6. Cooling energy recovery in Climate Zones 3C, 4C, 5B, 5C, 6B, 7 and 8.
  7. Systems requiring dehumidification that employ energy recovery in series with the cooling coil.
  8. Where the largest source of air exhausted at a single location at the building exterior is less than 75 percent of the design outdoor air flow rate.
  9. Systems expected to operate less than 20 hours per week at the outdoor air percentage covered by Table C403.7.4(1).
  10. Systems exhausting toxic, flammable, paint or corrosive fumes or dust.
  11. Commercial kitchen hoods used for collecting and removing grease vapors and smoke.

TABLE C403.7.4(1)

ENERGY RECOVERY REQUIREMENT (Ventilation systems operating less than 8,000 hours per year)

CLIMATE ZONEPERCENT (%) OUTDOOR AIR AT FULL DESIGN AIRFLOW RATE
≥ 10% and < 20%≥ 20% and < 30%≥ 30% and < 40%≥ 40% and <
50%
≥ 50% and <
60%
≥ 60% and <
70%
≥ 70% and <
80%
≥ 80%
DESIGN SUPPLY FAN AIRFLOW RATE (cfm)
3B, 3C, 4B, 4C, 5BNRNRNRNRNRNRNRNR
1B, 2B, 5CNRNRNRNR≥ 26,000≥ 12,000≥ 5,000≥ 4,000
6B≥ 28,000≥ 26,5000≥ 11,000≥ 5,500≥ 4,500≥ 3,500≥ 2,500≥ 1,500
1A, 2A, 3A, 4A,
5A, 6A
≥ 26,000≥ 16,000≥ 5,500≥ 4,500≥ 3,500≥ 2,000≥ 1,000> 120
7,8≥ 4,500≥ 4,000≥ 2,500≥ 1,000> 140> 120> 100> 80

For SI: 1 cfm = 0.4719 L/s.

NR = Not Required.

TABLE C403.7.4(2)

ENERGY RECOVERY REQUIREMENT (Ventilation systems operating not less than 8,000 hours per year)

CLIMATE ZONEPERCENT (%) OUTDOOR AIR AT FULL DESIGN AIRFLOW RATE
≥ 10% and
< 20%
≥ 20% and
< 30%
≥ 30% and
< 40%
≥ 40% and
< 50%
≥ 50% and
< 60%
≥ 60% and
< 70%
≥ 70% and
< 80%
≥ 80%
Design Supply Fan Airflow Rate (cfm)
3CNRNRNRNRNRNRNRNR
1B, 2B, 3B, 4C, 5CNR≥ 19,500≥ 9,000≥ 5,000≥ 4,000≥ 3,000≥ 1,500≥ 120
1A, 2A, 3A, 4B, 5B≥ 2,500≥ 2,000≥ 1,000≥ 500≥ 140≥ 120≥ 100≥ 80
4A, 5A, 6A, 6B, 7, 8≥ 200≥ 130≥ 100≥ 80≥ 70≥ 60≥ 50≥ 40

For SI: 1 cfm = 0.4719 L/s.

NR = Not Required.

Replacement air introduced directly into the exhaust hood cavity shall not be greater than 10 percent of the hood exhaust airflow rate. Conditioned supply air delivered to any space shall not exceed the greater of the following:

  1. The ventilation rate required to meet the space heating or cooling load.
  2. The hood exhaust flow minus the available transfer air from adjacent space where available transfer air is considered to be that portion of outdoor ventilation air not required to satisfy other exhaust needs, such as restrooms, and not required to maintain pressurization of adjacent spaces.

Where total kitchen hood exhaust airflow rate is greater than 5,000 cfm (2360 L/s), each hood shall be a factory-built commercial exhaust hood listed by a nationally recognized testing laboratory in compliance with UL 710. Each hood shall have a maximum exhaust rate as specified in Table C403.7.5 and shall comply with one of the following:

  1. Not less than 50 percent of all replacement air shall be transfer air that would otherwise be exhausted.
  2. Demand ventilation systems on not less than 75 percent of the exhaust air that are configured to provide not less than a 50-percent reduction in exhaust and replacement air system airflow rates, including controls necessary to modulate airflow in response to appliance operation and to maintain full capture and containment of smoke, effluent and combustion products during cooking and idle.
  3. Listed energy recovery devices with a sensible heat recovery effectiveness of not less than 40 percent on not less than 50 percent of the total exhaust airflow.

Where a single hood, or hood section, is installed over appliances with different duty ratings, the maximum allowable flow rate for the hood or hood section shall be based on the requirements for the highest appliance duty rating under the hood or hood section.

Exception: Where not less than 75 percent of all the replacement air is transfer air that would otherwise be exhausted.

TABLE C403.7.5

MAXIMUM NET EXHAUST FLOW RATE, CFM PER LINEAR FOOT OF HOOD LENGTH

TYPE OF HOODLIGHT-DUTY
EQUIPMENT
MEDIUM-DUTY
EQUIPMENT
HEAVY-DUTY
EQUIPMENT
EXTRA-HEAVY-DUTY
EQUIPMENT
Wall-mounted canopy140210280385
Single island280350420490
Double island (per side)175210280385
Eyebrow175175NANA
Backshelf/Pass-over210210280NA

For SI: 1 cfm = 0.4719 L/s; 1 foot = 305 mm.

NA = Not Allowed.

In Group R-1 buildings containing more than 50 guestrooms, each guestroom shall be provided with controls complying with the provisions of Sections C403.7.6.1 and C403.7.6.2. Card key controls comply with these requirements.
Controls shall be provided on each HVAC system that are capable of and configured to automatically raise the cooling setpoint and lower the heating setpoint by not less than 4°F (2°C) from the occupant setpoint within 30 minutes after the occupants have left the guestroom. The controls shall be capable of and configured to automatically raise the cooling setpoint to not lower than 80°F (27°C) and lower the heating setpoint to not higher than 60°F (16°C) when the guestroom is unrented or has not been continuously occupied for more than 16 hours or a networked guestroom control system indicates that the guestroom is unrented and the guestroom is unoccupied for more than 30 minutes. A networked guestroom control system that is capable of returning the thermostat setpoints to default occupied setpoints 60 minutes prior to the time a guestroom is scheduled to be occupied is not precluded by this section. Cooling that is capable of limiting relative humidity with a setpoint not lower than 65-percent relative humidity during unoccupied periods is not precluded by this section.

Controls shall be provided on each HVAC system that are capable of and configured to automatically turn off the ventilation and exhaust fans within 30 minutes of the occupants leaving the guestroom, or isolation devices shall be provided to each guestroom that are capable of automatically shutting off the supply of outdoor air to and exhaust air from the guestroom.

Exception: Guestroom ventilation systems are not precluded from having an automatic daily pre-occupancy purge cycle that provides daily outdoor air ventilation during unrented periods at the design ventilation rate for 60 minutes, or at a rate and duration equivalent to one air change.

Outdoor air intake and exhaust openings and stairway and shaft vents shall be provided with Class I motorized dampers. The dampers shall have an air leakage rate not greater than 4 cfm/ft2 (20.3 L/s • m2) of damper surface area at 1.0 inch water gauge (249 Pa) and shall be labeled by an approved agency when tested in accordance with AMCA 500D for such purpose.

Outdoor air intake and exhaust dampers shall be installed with automatic controls configured to close when the systems or spaces served are not in use or during unoccupied period warm-up and setback operation, unless the systems served require outdoor or exhaust air in accordance with the International Mechanical Code or the dampers are opened to provide intentional economizer cooling.

Stairway and shaft vent dampers shall be installed with automatic controls configured to open upon the activation of any fire alarm initiating device of the building’s fire alarm system or the interruption of power to the damper.

Exception: Nonmotorized gravity dampers shall be an alternative to motorized dampers for exhaust and relief openings as follows:

  1. In buildings less than three stories in height above grade plane.
  2. In buildings of any height located in Climate Zones 1, 2 or 3.
  3. Where the design exhaust capacity is not greater than 300 cfm (142 L/s).

Nonmotorized gravity dampers shall have an air leakage rate not greater than 20 cfm/ft2 (101.6 L/s • m2) where not less than 24 inches (610 mm) in either dimension and 40 cfm/ft2 (203.2 L/s • m2) where less than 24 inches (610 mm) in either dimension. The rate of air leakage shall be determined at 1.0 inch water gauge (249 Pa) when tested in accordance with AMCA 500D for such purpose. The dampers shall be labeled by an approved agency.

Fans in HVAC systems shall comply with Sections C403.8.1 through C403.8.5.1.

Each HVAC system having a total fan system motor nameplate horsepower exceeding 5 hp (3.7 kW) at fan system design conditions shall not exceed the allowable fan system motor nameplate hp (Option 1) or fan system bhp (Option 2) shown in Table C403.8.1(1). This includes supply fans, exhaust fans, return/relief fans, and fan-powered terminal units associated with systems providing heating or cooling capability. Single-zone variable air volume systems shall comply with the constant volume fan power limitation.

Exceptions:

  1. Hospital, vivarium and laboratory systems that utilize flow control devices on exhaust or return to maintain space pressure relationships necessary for occupant health and safety or environmental control shall be permitted to use variable volume fan power limitation.
  2. Individual exhaust fans with motor nameplate horsepower of 1 hp (0.746 kW) or less are exempt from the allowable fan horsepower requirement.

TABLE C403.8.1(1)

FAN POWER LIMITATION

LIMITCONSTANT VOLUMEVARIABLE VOLUME
Option 1: Fan system motor nameplate hpAllowable nameplate motor hphp ≤ CFMS × 0.0011hp ≤ CFMS × 0.0015
Option 2: Fan system bhpAllowable fan system bhpbhp ≤ CFMS × 0.00094 + Abhp ≤ CFMS × 0.0013 + A

For SI: 1 bhp = 735.5 W, 1 hp = 745.5 W, 1 cfm = 0.4719 L/s.

where:

CFMS = The maximum design supply airflow rate to conditioned spaces served by the system in cubic feet per minute.

hp = The maximum combined motor nameplate horsepower.

bhp = The maximum combined fan brake horsepower.

A = Sum of [PD × CFMD / 4131].

where:

PD = Each applicable pressure drop adjustment from Table C403.8.1(2) in. w.c.

CFMD = The design airflow through each applicable device from Table C403.8.1(2) in cubic feet per minute.

TABLE C403.8.1(2)

FAN POWER LIMITATION PRESSURE DROP ADJUSTMENT

DEVICEADJUSTMENT
Credits
Return air or exhaust systems required by code or accreditation
standards to be fully ducted, or systems required to maintain
air pressure differentials between adjacent rooms
0.5 inch w.c. (2.15 inches w.c. for laboratory and vivarium systems)
Return and exhaust airflow control devices0.5 inch w.c.
Exhaust filters, scrubbers or other exhaust treatmentThe pressure drop of device calculated at fan system design condition
Particulate filtration credit: MERV 9 thru 120.5 inch w.c.
Particulate filtration credit: MERV 13 thru 150.9 inch w.c.
Particulate filtration credit: MERV 16 and greater and
electronically enhanced filters
Pressure drop calculated at 2x clean filter pressure drop at
fan system design condition.
Carbon and other gas-phase air cleanersClean filter pressure drop at fan system design condition.
Biosafety cabinetPressure drop of device at fan system design condition.
Energy recovery device, other than coil runaround loopFor each airstream, (2.2 x energy recovery effectiveness - 0.5) inch w.c.
Coil runaround loop0.6 inch w.c. for each airstream.
Evaporative humidifier/cooler in series with another
cooling coil
Pressure drop of device at fan system design conditions.
Sound attenuation section (fans serving spaces with design
background noise goals below NC35)
0.15 inch w.c.
Exhaust system serving fume hoods0.35 inch w.c.
Laboratory and vivarium exhaust systems in high-rise buildings0.25 inch w.c./100 feet of vertical duct exceeding 75 feet.
Deductions
Systems without central cooling device- 0.6 inch w.c.
Systems without central heating device- 0.3 inch w.c.
Systems with central electric resistance heat- 0.2 inch w.c.

For SI: 1 inch w.c. = 249 Pa, 1 inch = 25.4 mm.

w.c. = water column, NC = Noise criterion.

For each fan, the fan brake horsepower shall be indicated on the construction documents and the selected motor shall be not larger than the first available motor size greater than the following:

  1. For fans less than 6 bhp (4413 W), 1.5 times the fan brake horsepower.
  2. For fans 6 bhp (4413 W) and larger, 1.3 times the fan brake horsepower.
  3. Systems complying with Section C403.8.1 fan system motor nameplate hp (Option 1).

Exception: Fans with motor nameplate horsepower less than 1 hp (746 W) are exempt from this section.

Fans shall have a fan efficiency grade (FEG) of not less than 67, as determined in accordance with AMCA 205 by an approved, independent testing laboratory and labeled by the manufacturer. The total efficiency of the fan at the design point of operation shall be within 15 percentage points of the maximum total efficiency of the fan.

Exception: The following fans are not required to have a fan efficiency grade:

  1. Fans of 5 hp (3.7 kW) or less as follows:

    1. 1.1. Individual fans with a motor nameplate horsepower of 5 hp (3.7 kW) or less, unless Exception 1.2 applies.
    2. 1.2. Multiple fans in series or parallel that have a combined motor nameplate horsepower of 5 hp (3.7 kW) or less and are operated as the functional equivalent of a single fan.
  2. Fans that are part of equipment covered in Section C403.3.2.
  3. Fans included in an equipment package certified by an approved agency for air or energy performance.
  4. Powered wall/roof ventilators.
  5. Fans outside the scope of AMCA 205.
  6. Fans that are intended to operate only during emergency conditions.

Motors for fans that are not less than 1/12 hp (0.062 kW) and less than 1 hp (0.746 kW) shall be electronically commutated motors or shall have a minimum motor efficiency of 70 percent, rated in accordance with DOE 10 CFR 431. These motors shall have the means to adjust motor speed for either balancing or remote control. The use of belt-driven fans to sheave adjustments for airflow balancing instead of a varying motor speed shall be permitted.


Exceptions: The following motors are not required to comply with this section

  1. Motors in the airstream within fan coils and terminal units that only provide heating to the space served.
  2. Motors in space-conditioning equipment that comply with Section C403.3.2 or Sections C403.8.1. through C403.8.3.
  3. Motors that comply with Section C405.7.
Controls shall be provided for fans in accordance with Section C403.8.5.1 and as required for specific systems provided in Section C403.

Each cooling system listed in Table C403.8.5.1 shall be designed to vary the indoor fan airflow as a function of load and shall comply with the following requirements:

  1. Direct expansion (DX) and chilled water cooling units that control the capacity of the mechanical cooling directly based on space temperature shall have not fewer than two stages of fan control. Low or minimum speed shall not be greater than 66 percent of full speed. At low or minimum speed, the fan system shall draw not more than 40 percent of the fan power at full fan speed. Low or minimum speed shall be used during periods of low cooling load and ventilation-only operation.
  2. Other units including DX cooling units and chilled water units that control the space temperature by modulating the airflow to the space shall have modulating fan control. Minimum speed shall be not greater than 50 percent of full speed. At minimum speed the fan system shall draw not more than 30 percent of the power at full fan speed. Low or minimum speed shall be used during periods of low cooling load and ventilation-only operation.
  3. Units that include an air-side economizer in accordance with Section C403.5 shall have not fewer than two speeds of fan control during economizer operation.

Exceptions:

  1. Modulating fan control is not required for chilled water and evaporative cooling units with fan motors of less than 1 hp (0.746 kW) where the units are not used to provide ventilation air and the indoor fan cycles with the load.
  2. Where the volume of outdoor air required to comply with the ventilation requirements of the International Mechanical Code at low speed exceeds the air that would be delivered at the speed defined in Section C403.8.5, the minimum speed shall be selected to provide the required ventilation air.

TABLE C403.8.5.1

COOLING SYSTEMS

COOLING
SYSTEM TYPE
FAN
MOTOR SIZE
MECHANICAL
COOLING CAPACITY
DX coolingAny≥ 65,000 Btu/h
Chilled water and
evaporative cooling
1/4 hpAny

For SI: 1 British thermal unit per hour = 0.2931 W; 1 hp = 0.746 kW.

Heat rejection equipment, including air-cooled condensers, dry coolers, open-circuit cooling towers, closed-circuit cooling towers and evaporative condensers, shall comply with this section.

Exception: Heat rejection devices where energy usage is included in the equipment efficiency ratings listed in Tables C403.3.2(6) and C403.3.2(7).

Each fan system powered by an individual motor or array of motors with connected power, including the motor service factor, totaling 5 hp (3.7 kW) or more shall have controls and devices configured to automatically modulate the fan speed to control the leaving fluid temperature or condensing temperature and pressure of the heat rejection device. Fan motor power input shall be not more than 30 percent of design wattage at 50 percent of the design airflow.


Exceptions:

  1. Fans serving multiple refrigerant or fluid cooling circuits.
  2. Condenser fans serving flooded condensers.
Multiple-cell heat rejection equipment with variable speed fan drives shall be controlled to operate the maximum number of fans allowed that comply with the manufacturer’s requirements for all system components and so that all fans operate at the same fan speed required for the instantaneous cooling duty, as opposed to staged on and off operation. The minimum fan speed shall be the minimum allowable speed of the fan drive system in accordance with the manufacturer’s recommendations.

Centrifugal fan open-circuit cooling towers with a combined rated capacity of 1,100 gpm (4164 L/m) or greater at 95°F (35°C) condenser water return, 85°F (29°C) condenser water supply, and 75°F (24°C) outdoor air wet-bulb temperature shall meet the energy efficiency requirement for axial fan open-circuit cooling towers listed in Table C403.3.2(8).

Exception: Centrifugal open-circuit cooling towers that are designed with inlet or discharge ducts or require external sound attenuation.

Open-circuit cooling towers used on water-cooled chiller systems that are configured with multiple- or variable-speed condenser water pumps shall be designed so that all open- circuit cooling tower cells can be run in parallel with the larger of the flow that is produced by the smallest pump at its minimum expected flow rate or at 50 percent of the design flow for the cell.

Condenser heat recovery shall be installed for heating or reheating of service hot water provided that the facility operates 24 hours a day, the total installed heat capacity of water-cooled systems exceeds 6,000,000 Btu/hr (1 758 kW) of heat rejection, and the design service water heating load exceeds 1,000,000 Btu/h (293 kW).

The required heat recovery system shall have the capacity to provide the smaller of the following:

  1. Sixty percent of the peak heat rejection load at design conditions.
  2. The preheating required to raise the peak service hot water draw to 85°F (29°C).

Exceptions:

  1. Facilities that employ condenser heat recovery for space heating or reheat purposes with a heat recovery design exceeding 30 percent of the peak water-cooled condenser load at design conditions.
  2. Facilities that provide 60 percent of their service water heating from site solar or site recovered energy or from other sources.
Refrigeration equipment shall have an energy use in kWh/day not greater than the values of Tables C403.10.1(1) and C403.10.1(2) when tested and rated in accordance with AHRI Standard 1200. The energy use shall be verified through certification under an approved certification program or, where a certification program does not exist, the energy use shall be supported by data furnished by the equipment manufacturer.

Refrigerated warehouse coolers and refrigerated warehouse freezers shall comply with this section. Walk-in coolers and walk-in freezers that are neither site assembled nor site constructed shall comply with the following:

  1. Be equipped with automatic door-closers that firmly close walk-in doors that have been closed to within 1 inch (25 mm) of full closure.

    Exception: Automatic closers are not required for doors more than 45 inches (1143 mm) in width or more than 7 feet (2134 mm) in height.

  2. Doorways shall have strip doors, curtains, spring-hinged doors or other method of minimizing infiltration when doors are open.
  3. Walk-in coolers and refrigerated warehouse coolers shall contain wall, ceiling, and door insulation of not less than R-25 and walk-in freezers and refrigerated warehouse freezers shall contain wall, ceiling and door insulation of not less than R-32.

    Exception: Glazed portions of doors or structural members need not be insulated.

  4. Walk-in freezers shall contain floor insulation of not less than R-28.
  5. Transparent reach-in doors for walk-in freezers and windows in walk-in freezer doors shall be of triple-pane glass, either filled with inert gas or with heat-reflective treated glass.
  6. Windows and transparent reach-in doors for walk-in coolers shall be of double-pane or triple-pane, inert gas-filled, heat-reflective treated glass.
  7. Evaporator fan motors that are less than 1 hp (0.746 kW) and less than 460 volts shall use electronically commutated motors, brushless direct- current motors, or 3-phase motors.
  8. Condenser fan motors that are less than 1 hp (0.746 kW) shall use electronically commutated motors, permanent split capacitor-type motors or 3-phase motors.
  9. Where antisweat heaters without antisweat heater controls are provided, they shall have a total door rail, glass and frame heater power draw of not more than 7.1 W/ft2 (76 W/m2) of door opening for walk-in freezers and 3.0 W/ft2 (32 W/m2) of door opening for walk-in coolers.
  10. Where antisweat heater controls are provided, they shall reduce the energy use of the antisweat heater as a function of the relative humidity in the air outside the door or to the condensation on the inner glass pane.
  11. Lights in walk-in coolers, walk-in freezers, refrigerated warehouse coolers and refrigerated warehouse freezers shall either use light sources with an efficacy of not less than 40 lumens per watt, including ballast losses, or shall use light sources with an efficacy of not less than 40 lumens per watt, including ballast losses, in conjunction with a device that turns off the lights within 15 minutes when the space is not occupied.

TABLE C403.10.1(1)

MINIMUM EFFICIENCY REQUIREMENTS: COMMERCIAL REFRIGERATION

EQUIPMENT TYPEAPPLICATIONENERGY USE LIMITS
(kWh per day)a
TEST PROCEDURE
Refrigerator with solid doorsHolding Temperature0.10 • V + 2.04AHRI 1200
Refrigerator with transparent doors0.12 × V + 3.34
Freezers with solid doors0.40 × V + 1.38
Freezers with transparent doors0.75 × V + 4.10
Refrigerators/freezers with solid doorsthe greater of 0.12 × V + 3.34 or 0.70
Commercial refrigeratorsPulldown0.126 × V + 3.51
  1. V = volume of the chiller or frozen compartment as defined in AHAM-HRF-1.

TABLE C403.10.1(2)

MINIMUM EFFICIENCY REQUIREMENTS: COMMERCIAL REFRIGERATORS AND FREEZERS

EQUIPMENT TYPEENERGY USE LIMITS
(kWh/day)a, b
TEST
PROCEDURE
Equipment ClasscFamily CodeOperating ModeRating Temperature
VOP.RC.MVertical openRemote condensingMedium0.82 × TDA + 4.07AHRI 1200
SVO.RC.MSemivertical openRemote condensingMedium0.83 × TDA + 3.18
HZO.RC.MHorizontal openRemote condensingMedium0.35 × TDA + 2.88
VOP.RC.LVertical openRemote condensingLow2.27 × TDA + 6.85
HZO.RC.LHorizontal openRemote condensingLow0.57 × TDA + 6.88
VCT.RC.MVertical
transparent door
Remote condensingMedium0.22 TDA + 1.95
VCT.RC.LVertical
transparent door
Remote condensingLow0.56 × TDA + 2.61
SOC.RC.MService over counterRemote condensingMedium0.51 × TDA + 0.11
VOP.SC.MVertical openSelf-containedMedium1.74 × TDA + 4.71
SVO.SC.MSemivertical openSelf-containedMedium1.73 × TDA + 4.59
HZO.SC.MHorizontal openSelf-containedMedium0.77 × TDA + 5.55
HZO.SC.LHorizontal openSelf-containedLow1.92 × TDA + 7.08
VCT.SC.IVertical
transparent door
Self-containedIce cream0.67 × TDA + 3.29
VCS.SC.IVertical solid doorSelf-containedIce cream0.38 × V + 0.88
HCT.SC.IHorizontal
transparent door
Self-containedIce cream0.56 × TDA + 0.43
SVO.RC.LSemivertical openRemote condensingLow2.27 × TDA + 6.85
VOP.RC.IVertical openRemote condensingIce cream2.89 × TDA + 8.7
SVO.RC.ISemivertical openRemote condensingIce cream2.89 × TDA + 8.7
HZO.RC.IHorizontal openRemote condensingIce cream0.72 × TDA + 8.74
VCT.RC.IVertical
transparent door
Remote condensingIce cream0.66 × TDA + 3.05
HCT.RC.MHorizontal
transparent door
Remote condensingMedium0.16 × TDA + 0.13
HCT.RC.LHorizontal
transparent door
Remote condensingLow0.34 × TDA + 0.26
HCT.RC.IHorizontal
transparent door
Remote condensingIce cream0.4 × TDA + 0.31
VCS.RC.MVertical solid doorRemote condensingMedium0.11 × V + 0.26
VCS.RC.LVertical solid doorRemote condensingLow0.23 × V + 0.54
VCS.RC.IVertical solid doorRemote condensingIce cream0.27 × V + 0.63
HCS.RC.MHorizontal solid doorRemote condensingMedium0.11 × V + 0.26
HCS.RC.LHorizontal solid doorRemote condensingLow0.23 × V + 0.54
HCS.RC.IHorizontal solid doorRemote condensingIce cream0.27 × V + 0.63
HCS.RC.IHorizontal solid doorRemote condensingIce cream0.27 × V + 0.63
SOC.RC.LService over counterRemote condensingLow1.08 × TDA + 0.22
SOC.RC.IService over counterRemote condensingIce cream1.26 × TDA + 0.26
VOP.SC.LVertical openSelf-containedLow4.37 × TDA + 11.82
VOP.SC.IVertical openSelf-containedIce cream5.55 × TDA + 15.02
SVO.SC.LSemivertical openSelf-containedLow4.34 × TDA + 11.51
SVO.SC.ISemivertical openSelf-containedIce cream5.52 × TDA + 14.63
HZO.SC.IHorizontal openSelf-containedIce cream2.44 × TDA + 9.0
SOC.SC.IService over counterSelf-containedIce cream1.76 × TDA + 0.36
HCS.SC.IHorizontal solid doorSelf-containedIce cream0.38 × V + 0.88
  1. V = Volume of the case, as measured in accordance with Appendix C of AHRI 1200.
  2. TDA = Total display area of the case, as measured in accordance with Appendix D of AHRI 1200.
  3. Equipment class designations consist of a combination [in sequential order separated by periods (AAA).(BB).(C)] of:

    (AAA)An equipment family code where:
    VOP=vertical open
    SVO=semivertical open
    HZO=horizontal open
    HCT=horizontal transparent doors
    HCS=horizontal solid doors
    SOC=service over counter
    (BB)An operating mode code:
    RC=remote condensing
    SC=self-contained
    (C)A rating temperature code:
    M=medium temperature (38°F)
    L=low temperature (0°F)
    I=ice-cream temperature (15°F)

    For example, “VOP.RC.M” refers to the “vertical-open, remote-condensing, medium-temperature” equipment class.

Site-assembled or site-constructed walk-in coolers and walk-in freezers shall comply with the following:

  1. Automatic door closers shall be provided that fully close walk-in doors that have been closed to within 1 inch (25 mm) of full closure.

    Exception: Closers are not required for doors more than 45 inches (1143 mm) in width or more than 7 feet (2134 mm) in height.

  2. Doorways shall be provided with strip doors, curtains, spring-hinged doors or other method of minimizing infiltration when the doors are open.
  3. Walls shall be provided with insulation having a thermal resistance of not less than R-25, ceilings shall be provided with insulation having a thermal resistance of not less than R-25 and doors of walk-in coolers and walk-in freezers shall be provided with insulation having a thermal resistance of not less than R-32.

    Exception: Insulation is not required for glazed portions of doors or at structural members associated with the walls, ceiling or door frame.

  4. The floor of walk-in freezers shall be provided with insulation having a thermal resistance of not less than R-28.
  5. Transparent reach-in doors for and windows in opaque walk-in freezer doors shall be provided with triple-pane glass having the interstitial spaces filled with inert gas or provided with heat-reflective treated glass.
  6. Transparent reach-in doors for and windows in opaque walk-in cooler doors shall be double-pane heat-reflective treated glass having the interstitial space gas filled.
  7. Evaporator fan motors that are less than 1 hp (0.746 kW) and less than 460 volts shall be electronically commutated motors or 3-phase motors.
  8. Condenser fan motors that are less than 1 hp (0.746 kW) in capacity shall be of the electronically commutated or permanent split capacitor-type or shall be 3-phase motors.

    Exception: Fan motors in walk-in coolers and walk-in freezers combined in a single enclosure greater than 3,000 square feet (279 m2) in floor area are exempt.

  9. Antisweat heaters that are not provided with anti-sweat heater controls shall have a total door rail, glass and frame heater power draw not greater than 7.1 W/ft2 (76 W/m2) of door opening for walk-in freezers, and not greater than 3.0 W/ft2 (32 W/m2) of door opening for walk-in coolers.
  10. Antisweat heater controls shall be configured to reduce the energy use of the antisweat heater as a function of the relative humidity in the air outside the door or to the condensation on the inner glass pane.
  11. Light sources shall have an efficacy of not less than 40 lumens per Watt, including any ballast losses, or shall be provided with a device that automatically turns off the lights within 15 minutes of when the walk-in cooler or walk-in freezer was last occupied.

Effective January 1, 2020, walk-in coolers and walk-in freezers shall meet the requirements of Tables C403.10.2.1(1), C403.10.2.1(2) and C403.10.2.1(3).

TABLE C403.10.2.1(1)

WALK-IN COOLER AND FREEZER DISPLAY DOOR EFFICIENCY REQUIREMENTSa

CLASS DESCRIPTORCLASSMAXIMUM ENERGY CONSUMPTION (kWh/day)a
Display door, medium temperatureDD, M0.04 x Add + 0.41
Display door, low temperatureDD, L0.15 x Add + 0.29
  1. Add is the surface area of the display door.

TABLE C403.10.2.1(2)

WALK-IN COOLER AND FREEZER NONDISPLAY DOOR EFFICIENCY REQUIREMENTSa

CLASS DESCRIPTORCLASSMAXIMUM ENERGY CONSUMPTION (kWh/day)a
Passage door, medium temperaturePD, M0.05 x And + 1.7
Passage door, low temperaturePD, L0.14 x And + 4.8
Freight door, medium temperatureFD, M0.04 x And + 1.9
Freight door, low temperatureFD, L0.12 x And + 5.6
  1. And is the surface area of the nondisplay door.

TABLE C403.10.2.1(3)

WALK-IN COOLER AND FREEZER REFRIGERATION SYSTEM EFFICIENCY REQUIREMENTS

CLASS DESCRIPTORCLASSMINIMUM ANNUAL WALK-IN ENERGY FACTOR AWEF
(Btu/W-h)
Dedicated condensing, medium temperature, indoor systemDC.M.I5.61
Dedicated condensing, medium temperature, indoor system,
> 9,000 Btu/h capacity
DC.M.I,
> 9,000
5.61
Dedicated condensing, medium temperature, outdoor systemDC.M.I7.60
Dedicated condensing, medium temperature, outdoor system,
> 9,000 Btu/h capacity
DC.M.I,
> 9,000
7.60

Site-assembled or site-constructed refrigerated display cases shall comply with the following:

  1. Lighting and glass doors in refrigerated display cases shall be controlled by one of the following:

    1. 1.1. Time-switch controls to turn off lights during nonbusiness hours. Timed overrides for display cases shall turn the lights on for up to 1 hour and shall automatically time out to turn the lights off.
    2. 1.2. Motion sensor controls on each display case section that reduce lighting power by not less than 50 percent within 3 minutes after the area within the sensor range is vacated.
  2. Low-temperature display cases shall incorporate temperature-based defrost termination control with a time-limit default. The defrost cycle shall terminate first on an upper temperature limit breach and second upon a time limit breach.
  3. Antisweat heater controls shall reduce the energy use of the antisweat heater as a function of the relative humidity in the air outside the door or to the condensation on the inner glass pane.

Refrigerated display cases, walk-in coolers or walk-in freezers that are served by remote compressors and remote condensers not located in a condensing unit, shall comply with Sections C403.10.4.1 and C403.10.4.2.

Exception: Systems where the working fluid in the refrigeration cycle goes through both subcritical and super-critical states (transcritical) or that use ammonia refrigerant are exempt.

Fan-powered condensers shall comply with the following:

  1. The design saturated condensing temperatures for air-cooled condensers shall not exceed the design dry-bulb temperature plus 10°F (5.6°C) for low-temperature refrigeration systems, and the design dry- bulb temperature plus 15°F (8°C) for medium temperature refrigeration systems where the saturated condensing temperature for blend refrigerants shall be determined using the average of liquid and vapor temperatures as converted from the condenser drain pressure.
  2. Condenser fan motors that are less than 1 hp (0.75 kW) shall use electronically commutated motors, permanent split-capacitor-type motors or 3-phase motors.
  3. Condenser fans for air-cooled condensers, evaporatively cooled condensers, air- or water-cooled fluid coolers or cooling towers shall reduce fan motor demand to not more than 30 percent of design wattage at 50 percent of design air volume, and incorporate one of the following continuous variable speed fan control approaches:

    1. 3.1. Refrigeration system condenser control for air-cooled condensers shall use variable setpoint control logic to reset the condensing temperature setpoint in response to ambient dry-bulb temperature.
    2. 3.2. Refrigeration system condenser control for evaporatively cooled condensers shall use variable setpoint control logic to reset the condensing temperature setpoint in response to ambient wet-bulb temperature.
  4. Multiple fan condensers shall be controlled in unison.
  5. The minimum condensing temperature setpoint shall be not greater than 70°F (21°C).

Refrigeration compressor systems shall comply with the following:

  1. Compressors and multiple-compressor system suction groups shall include control systems that use floating suction pressure control logic to reset the target suction pressure temperature based on the temperature requirements of the attached refrigeration display cases or walk-ins.

    Exception: Controls are not required for the following:

    1. Single-compressor systems that do not have variable capacity capability.
    2. Suction groups that have a design saturated suction temperature of 30°F (-1.1°C) or higher, suction groups that comprise the high stage of a two-stage or cascade system, or suction groups that primarily serve chillers for secondary cooling fluids.
  2. Liquid subcooling shall be provided for all low-temperature compressor systems with a design cooling capacity equal to or greater than 100,000 Btu/hr (29.3 kW) with a design-saturated suction temperature of -10°F (-23°C) or lower. The sub-cooled liquid temperature shall be controlled at a maximum temperature setpoint of 50°F (10°C) at the exit of the subcooler using either compressor economizer (interstage) ports or a separate compressor suction group operating at a saturated suction temperature of 18°F (-7.8°C) or higher.

    1. 2.1. Insulation for liquid lines with a fluid operating temperature less than 60°F (15.6°C) shall comply with Table C403.11.3.
    2. 3. Compressors that incorporate internal or external crankcase heaters shall provide a means to cycle the heaters off during compressor operation.
Ducts, plenums, piping and other elements that are part of an HVAC system shall be constructed and insulated in accordance with Sections C403.11.1 through C403.11.3.1.

Supply and return air ducts and plenums shall be insulated with not less than R-6 insulation where located in unconditioned spaces and where located outside the building with not less than R-8 insulation in Climate Zones 1 through 4 and not less than R-12 insulation in Climate Zones 5 through 8. Where located within a building envelope assembly, the duct or plenum shall be separated from the building exterior or unconditioned or exempt spaces by not less than R-8 insulation in Climate Zones 1 through 4 and not less than R-12 insulation in Climate Zones 5 through 8.

Exceptions:

  1. Where located within equipment.
  2. Where the design temperature difference between the interior and exterior of the duct or plenum is not greater than 15°F (8°C).

Ducts, air handlers and filter boxes shall be sealed. Joints and seams shall comply with Section 603.9 of the International Mechanical Code.

Ductwork shall be constructed and erected in accordance with the International Mechanical Code.

Longitudinal and transverse joints, seams and connections of supply and return ducts operating at a static pressure less than or equal to 2 inches water gauge (w.g.) (498 Pa) shall be securely fastened and sealed with welds, gaskets, mastics (adhesives), mas-tic-plus-embedded-fabric systems or tapes installed in accordance with the manufacturer’s instructions. Pressure classifications specific to the duct system shall be clearly indicated on the construction documents in accordance with the International Mechanical Code.

Exception: Locking-type longitudinal joints and seams, other than the snap-lock and button-lock types, need not be sealed as specified in this section.

Ducts and plenums designed to operate at a static pressure greater than 2 inches water gauge (w.g.) (498 Pa) but less than 3 inches w.g. (747 Pa) shall be insulated and sealed in accordance with Section C403.11.1. Pressure classifications specific to the duct system shall be clearly indicated on the construction documents in accordance with the International Mechanical Code.

C403.11.2.3 High-pressure duct systems (Mandatory)

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.

Ducts and plenums designed to operate at static pressures equal to or greater than 3 inches water gauge (747 Pa) shall be insulated and sealed in accordance with Section C403.11.1. In addition, ducts and plenums shall be leak tested in accordance with the SMACNA HVAC Air Duct Leakage Test Manual and shown to have a rate of air leakage (CL) less than or equal to 4.0 as determined in accordance with Equation 4-8.

(Equation 4-8)

where:

F = The measured leakage rate in cfm per 100 square feet of duct surface.

P = The static pressure of the test.

Documentation shall be furnished by the designer demonstrating that representative sections totaling not less than 25 percent of the duct area have been tested and that all tested sections comply with the requirements of this section.

Piping serving as part of a heating or cooling system shall be thermally insulated in accordance with Table C403.11.3.

Exceptions:

  1. Factory-installed piping within HVAC equipment tested and rated in accordance with a test procedure referenced by this code.
  2. Factory-installed piping within room fan-coils and unit ventilators tested and rated according to AHRI 440 (except that the sampling and variation provisions of Section 6.5 shall not apply) and AHRI 840, respectively.
  3. Piping that conveys fluids that have a design operating temperature range between 60°F (15°C) and 105°F (41°C).
  4. Piping that conveys fluids that have not been heated or cooled through the use of fossil fuels or electric power.
  5. Strainers, control valves, and balancing valves associated with piping 1 inch (25 mm) or less in diameter.
  6. Direct buried piping that conveys fluids at or below 60°F (15°C).

TABLE C403.11.3

MINIMUM PIPE INSULATION THICKNESS (in inches)a, c

FLUID OPERATING
TEMPERATURE RANGE
AND USAGE (°F)
INSULATION CONDUCTIVITYNOMINAL PIPE OR TUBE SIZE (inches)
Conductivity
Btu • in./(h • ft2• °F)b
Mean Rating Temperature, °F< 11 to < 1 1/21 1/2 to < 44 to < 8≥ 8
> 3500.32 – 0.342504.55.05.05.05.0
251 – 3500.29 – 0.322003.04.04.54.54.5
201 – 2500.27 – 0.301502.52.52.53.03.0
141 – 2000.25 – 0.291251.51.52.02.02.0
105 – 1400.21 – 0.281001.01.01.51.51.5
40 – 600.21 – 0.27750.50.51.01.01.0
< 400.20 – 0.26500.51.01.01.01.5

For SI: 1 inch = 25.4 mm, °C = [(°F) - 32]/1.8.

  1. For piping smaller than 11/2 inches and located in partitions within conditioned spaces, reduction of these thicknesses by 1 inch shall be permitted (before thickness adjustment required in footnote b) but not to a thickness less than 1 inch.
  2. For insulation outside the stated conductivity range, the minimum thickness (T) shall be determined as follows:

    where:

    T = minimum insulation thickness,

    r = actual outside radius of pipe,

    t = insulation thickness listed in the table for applicable fluid temperature and pipe size,

    K = conductivity of alternate material at mean rating temperature indicated for the applicable fluid temperature (Btu • in/h • ft2 • °F) and

    k = the upper value of the conductivity range listed in the table for the applicable fluid temperature.

  3. For direct-buried heating and hot water system piping, reduction of these thicknesses by 11/2 inches (38 mm) shall be permitted (before thickness adjustment required in footnote b but not to thicknesses less than 1 inch.
Piping insulation exposed to the weather shall be protected from damage, including that caused by sunlight, moisture, equipment maintenance and wind, and shall provide shielding from solar radiation that can cause degradation of the material. Adhesive tape shall not be permitted.
Mechanical systems providing heat outside of the thermal envelope of a building shall comply with Sections C403.12.1 through C403.12.3.

Systems installed to provide heat outside a building shall be radiant systems.

Such heating systems shall be controlled by an occupancy sensing device or a timer switch, so that the system is automatically de-energized when occupants are not present.

Snow- and ice-melting systems shall include automatic controls configured to shut off the system when the pavement temperature is above 50°F (10°C) and precipitation is not falling, and an automatic or manual control that is configured to shut off when the outdoor temperature is above 40°F (4°C).
Freeze protection systems, such as heat tracing of outdoor piping and heat exchangers, including self-regulating heat tracing, shall include automatic controls configured to shut off the systems when outdoor air temperatures are above 40°F (4°C) or when the conditions of the protected fluid will prevent freezing.
This section covers the minimum efficiency of, and controls for, service water-heating equipment and insulation of service hot water piping.

Water-heating equipment and hot water storage tanks shall meet the requirements of Table C404.2. The efficiency shall be verified through data furnished by the manufacturer of the equipment or through certification under an approved certification program. Water-heating equipment intended to be used to provide space heating shall meet the applicable provisions of Table C404.2.

TABLE C404.2

MINIMUM PERFORMANCE OF WATER-HEATING EQUIPMENT

EQUIPMENT TYPESIZE CATEGORY
(input)
SUBCATEGORY OR
RATING CONDITION
PERFORMANCE
REQUIREDa, b
TEST
PROCEDURE
Water heaters,
electric
≤ 12 kWd
Tabletope, ≥ 20 gallons and
≤ 120 gallons
0.93 - 0.00132V, EFDOE 10 CFR Part 430
Resistance ≥ 20 gallons
and ≤ 55 gallons
0.960 - 0.0003V, EF
Grid-enabledf > 75 gallons
and ≤ 120 gallons
1.061 - 0.00168V, EF
> 12 kWResistance(0.3 + 27/Vm), %/hANSI Z21.10.3
≤ 24 amps and
≤ 250 volts
Heat pump > 55 gallons
and ≤ 120 gallons
2.057 - 0.00113V, EFDOE 10 CFR Part 430
Storage water heaters,
gas
≤ 75,000 Btu/h≥ 20 gallons and
> 55 gallons
0.675 - 0.0015V, EFDOE 10 CFR Part 430
> 55 gallons and
≤ 100 gallons
0.8012 - 0.00078V, EF
> 75,000 Btu/h and
≤ 155,000 Btu/h
< 4,000 Btu/h/gal80% Et
ANSI Z21.10.3
> 155,000 Btu/h< 4,000 Btu/h/gal80% Et
Instantaneous
water heaters, gas
> 50,000 Btu/h and
< 200,000 Btu/hc
≥ 4,000 (Btu/h)/gal
and < 2 gal
0.82 - 0.00 19V, EFDOE 10 CFR Part 430
≥ 200,000 Btu/h≥ 4,000 Btu/h/gal
and < 10 gal
80% EtANSI Z21.10.3
≥ 200,000 Btu/h≥ 4,000 Btu/h/gal
and ≥ 10 gal
80% Et
Storage water heaters,
oil
≤ 105,000 Btu/h≥ 20 gal and
≤ 50 gallons
0.68 - 0.0019V, EFDOE 10 CFR Part 430
≥ 105,000 Btu/h< 4,000 Btu/h/gal80% Et
ANSI Z21.10.3
Instantaneous
water heaters, oil
≤ 210,000 Btu/h≥ 4,000 Btu/h/gal and
< 2 gal
0.59 - 0.0019V, EFDOE 10 CFR Part 430
> 210,000 Btu/h≥ 4,000 Btu/h/gal and
< 10 gal
80% EtANSI Z21.10.3
> 210,000 Btu/h≥ 4,000 Btu/h/gal and
≥ 10 gal
78% Et
Hot water supply boilers,
gas and oil
≥ 300,000 Btu/h and
< 12,500,000 Btu/h
≥ 4,000 Btu/h/gal and
< 10 gal
80% EtANSI Z21.10.3
Hot water supply boilers,
gas
≥ 300,000 Btu/h and
< 12,500,000 Btu/h
≥ 4,000 Btu/h/gal and
≥ 10 gal
80% Et
Hot water supply boilers,
oil
> 300,000 Btu/h and
< 12,500,000 Btu/h
> 4,000 Btu/h/gal and
> 10 gal
78% Et
Pool heaters, gas and oilAll82% EtASHRAE 146
Heat pump pool heatersAll4.0 COPAHRI 1160
Unfired storage tanksAllMinimum insulation
requirement R-12.5
(h • ft2 • °F)/Btu
(none)

For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, °C = [(°F) - 32]/1.8, 1 British thermal unit per hour = 0.2931 W, 1 gallon = 3.785 L, 1 British thermal unit per hour per gallon = 0.078 W/L.

  1. Energy factor (EF) and thermal efficiency (Et) are minimum requirements. In the EF equation, V is the rated volume in gallons.
  2. Standby loss (SL) is the maximum Btu/h based on a nominal 70°F temperature difference between stored water and ambient requirements. In the SL equation, Q is the nameplate input rate in Btu/h. In the equations for electric water heaters, V is the rated volume in gallons and Vm is the measured volume in gallons. In the SL equation for oil and gas water heaters and boilers, V is the rated volume in gallons.
  3. Instantaneous water heaters with input rates below 200,000 Btu/h shall comply with these requirements where the water heater is designed to heat water to temperatures 180°F or higher.
  4. Electric water heaters with an input rating of 12 kW (40,950 Btu/hr) or less that are designed to heat water to temperatures of 180°F or greater shall comply with the requirements for electric water heaters that have an input rating greater than 12 kW (40,950 Btu/h).
  5. A tabletop water heater is a water heater that is enclosed in a rectangular cabinet with a flat top surface not more than 3 feet in height.
  6. A grid-enabled water heater is an electric resistance water heater that meets all of the following:

    1. Has a rated storage tank volume of more than 75 gallons.
    2. Was manufactured on or after April 16, 2015.
    3. Is equipped at the point of manufacture with an activation lock.
    4. Bears a permanent label applied by the manufacturer that complies with all of the following:

      1. 4.1. Is made of material not adversely affected by water.
      2. 4.2. Is attached by means of nonwater-soluble adhesive.
      3. 4.3. Advises purchasers and end users of the intended and appropriate use of the product with the following notice printed in 16.5 point Arial Narrow Bold font: “IMPORTANT INFORMATION: This water heater is intended only for use as part of an electric thermal storage or demand response program. It will not provide adequate hot water unless enrolled in such a program and activated by your utility company or another program operator. Confirm the availability of a program in your local area before purchasing or installing this product.”

Gas-fired water-heating equipment installed in new buildings shall be in compliance with this section. Where a singular piece of water-heating equipment serves the entire building and the input rating of the equipment is 1,000,000 Btu/h (293 kW) or greater, such equipment shall have a thermal efficiency, Et, of not less than 90 percent. Where multiple pieces of water-heating equipment serve the building and the combined input rating of the water-heating equipment is 1,000,000 Btu/h (293 kW) or greater, the combined input-capacity-weighted-average thermal efficiency, Et, shall be not less than 90 percent.

Exceptions:

  1. Where not less than 25 percent of the annual service water-heating requirement is provided by on-site renewable energy or site-recovered energy, the minimum thermal efficiency requirements of this section shall not apply.
  2. The input rating of water heaters installed in individual dwelling units shall not be required to be included in the total input rating of service water-heating equipment for a building.
  3. The input rating of water heaters with an input rating of not greater than 100,000 Btu/h (29.3 kW) shall not be required to be included in the total input rating of service water-heating equipment for a building.
Storage tank-type water heaters and hot water storage tanks that have vertical water pipes connecting to the inlet and outlet of the tank shall be provided with integral heat traps at those inlets and outlets or shall have pipe-configured heat traps in the piping connected to those inlets and outlets. Tank inlets and outlets associated with solar water heating system circulation loops shall not be required to have heat traps.

Piping from a water heater to the termination of the heated water fixture supply pipe shall be insulated in accordance with Table C403.11.3. On both the inlet and outlet piping of a storage water heater or heated water storage tank, the piping to a heat trap or the first 8 feet (2438 mm) of piping, whichever is less, shall be insulated. Piping that is heat traced shall be insulated in accordance with Table C403.11.3 or the heat trace manufacturer’s instructions. Tubular pipe insulation shall be installed in accordance with the insulation manufacturer’s instructions. Pipe insulation shall be continuous except where the piping passes through a framing member. The minimum insulation thickness requirements of this section shall not supersede any greater insulation thickness requirements necessary for the protection of piping from freezing temperatures or the protection of personnel against external surface temperatures on the insulation.

Exception: Tubular pipe insulation shall not be required on the following:

  1. The tubing from the connection at the termination of the fixture supply piping to a plumbing fixture or plumbing appliance.
  2. Valves, pumps, strainers and threaded unions in piping that is 1 inch (25 mm) or less in nominal diameter.
  3. Piping from user-controlled shower and bath mixing valves to the water outlets.
  4. Cold-water piping of a demand recirculation water system.
  5. Tubing from a hot drinking-water heating unit to the water outlet.
  6. Piping at locations where a vertical support of the piping is installed.
  7. Piping surrounded by building insulation with a thermal resistance (R-value) of not less than R-3.
Heated water supply piping shall be in accordance with Section C404.5.1 or C404.5.2. The flow rate through 1/4-inch (6.4 mm) piping shall be not greater than 0.5 gpm (1.9 L/m). The flow rate through 5/16-inch (7.9 mm) piping shall be not greater than 1 gpm (3.8 L/m). The flow rate through 3/8-inch (9.5 mm) piping shall be not greater than 1.5 gpm (5.7 L/m).

The maximum allowable piping length from the nearest source of heated water to the termination of the fixture supply pipe shall be in accordance with the following. Where the piping contains more than one size of pipe, the largest size of pipe within the piping shall be used for determining the maximum allowable length of the piping in Table C404.5.1.

  1. For a public lavatory faucet, use the “Public lavatory faucets” column in Table C404.5.1.
  2. For all other plumbing fixtures and plumbing appliances, use the “Other fixtures and appliances” column in Table C404.5.1.

TABLE C404.5.1

PIPING VOLUME AND MAXIMUM PIPING LENGTHS

NOMINAL PIPE SIZE
(inches)
VOLUME
(liquid ounces per foot length)
MAXIMUM PIPING LENGTH
(feet)
Public lavatory faucetsOther fixtures and appliances
1/40.33650
5/160.5450
3/80.75350
1/21.5243
5/82132
3/430.521
7/840.516
150.513
11/480.58
11/2110.56
2 or larger180.54

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 liquid ounce = 0.030 L, 1 gallon = 128 ounces.

The water volume in the piping shall be calculated in accordance with Section C404.5.2.1. Water heaters, circulating water systems and heat trace temperature maintenance systems shall be considered to be sources of heated water.

The volume from the nearest source of heated water to the termination of the fixture supply pipe shall be as follows:

  1. For a public lavatory faucet: not more than 2 ounces (0.06 L).
  2. For other plumbing fixtures or plumbing appliances; not more than 0.5 gallon (1.89 L).
The volume shall be the sum of the internal volumes of pipe, fittings, valves, meters and manifolds between the nearest source of heated water and the termination of the fixture supply pipe. The volume in the piping shall be determined from the “Volume” column in Table C404.5.1. The volume contained within fixture shutoff valves, within flexible water supply connectors to a fixture fitting and within a fixture fitting shall not be included in the water volume determination. Where heated water is supplied by a recirculating system or heat-traced piping, the volume shall include the portion of the fitting on the branch pipe that supplies water to the fixture.
Heated-water circulation systems shall be in accordance with Section C404.6.1. Heat trace temperature maintenance systems shall be in accordance with Section C404.6.2. Controls for hot water storage shall be in accordance with Section C404.6.3. Automatic controls, temperature sensors and pumps shall be in a location with access. Manual controls shall be in a location with ready access.
Heated-water circulation systems shall be provided with a circulation pump. The system return pipe shall be a dedicated return pipe or a cold water supply pipe. Gravity and thermo-syphon circulation systems shall be prohibited. Controls for circulating hot water system pumps shall start the pump based on the identification of a demand for hot water within the occupancy. The controls shall automatically turn off the pump when the water in the circulation loop is at the desired temperature and when there is not a demand for hot water.
Electric heat trace systems shall comply with IEEE 515.1. Controls for such systems shall be able to automatically adjust the energy input to the heat tracing to maintain the desired water temperature in the piping in accordance with the times when heated water is used in the occupancy. Heat trace shall be arranged to be turned off automatically when there is not a demand for hot water.
The controls on pumps that circulate water between a water heater and a heated-water storage tank shall limit operation of the pump from heating cycle startup to not greater than 5 minutes after the end of the cycle.

Demand recirculation water systems shall have controls that comply with both of the following:

  1. The controls shall start the pump upon receiving a signal from the action of a user of a fixture or appliance, sensing the presence of a user of a fixture or sensing the flow of hot or tempered water to a fixture fitting or appliance.
  2. The controls shall limit the temperature of the water entering the cold-water piping to not greater than 104°F (40°C).
Drain water heat recovery units shall comply with CSA B55.2. Potable water-side pressure loss shall be less than 10 psi (69 kPa) at maximum design flow. For Group R occupancies, the efficiency of drain water heat recovery unit efficiency shall be in accordance with CSA B55.1.
The energy consumption of pools and permanent spas shall be controlled by the requirements in Sections C404.9.1 through C404.9.3.
The electric power to all heaters shall be controlled by an on-off switch that is an integral part of the heater, mounted on the exterior of the heater, or external to and within 3 feet (914 mm) of the heater in a location with ready access. Operation of such switch shall not change the setting of the heater thermostat. Such switches shall be in addition to a circuit breaker for the power to the heater. Gas-fired heaters shall not be equipped with continuously burning ignition pilots.

Time switches or other control methods that can automatically turn off and on heaters and pump motors according to a preset schedule shall be installed for heaters and pump motors. Heaters and pump motors that have built-in time switches shall be in compliance with this section.

Exceptions:

  1. Where public health standards require 24-hour pump operation.
  2. Pumps that operate solar- and waste-heat-recovery pool heating systems.

Outdoor heated pools and outdoor permanent spas shall be provided with a vapor-retardant cover or other approved vapor-retardant means.

Exception: Where more than 75 percent of the energy for heating, computed over an operating season of not fewer than 3 calendar months, is from site-recovered energy such as from a heat pump or on-site renewable energy system, covers or other vapor-retardant means shall not be required.

The energy consumption of electric-powered portable spas shall be controlled by the requirements of APSP 14.

This section covers lighting system controls, the maximum lighting power for interior and exterior applications and electrical energy consumption.

Dwelling units within multifamily buildings shall comply with Section R404.1. All other dwelling units shall comply with Section R404.1, or with Sections C405.2.4 and C405.3. Sleeping units shall comply with Section C405.2.4, and with Section R404.1 or C405.3. Lighting installed in walk-in coolers, walk-in freezers, refrigerated warehouse coolers and refrigerated warehouse freezers shall comply with the lighting requirements of Section C403.10.1 or C403.10.2.

Lighting systems shall be provided with controls that comply with one of the following.

  1. Lighting controls as specified in Sections C405.2.1 through C405.2.6.
  2. Luminaire level lighting controls (LLLC) and lighting controls as specified in Sections C405.2.1, C405.2.4 and C405.2.5. The LLLC luminaire shall be independently capable of:

    1. 2.1. Monitoring occupant activity to brighten or dim lighting when occupied or unoccupied, respectively.
    2. 2.2. Monitoring ambient light, both electric light and daylight, and brighten or dim artificial light to maintain desired light level.
    3. 2.3. For each control strategy, configuration and reconfiguration of performance parameters including; bright and dim setpoints, timeouts, dimming fade rates, sensor sensitivity adjustments, and wireless zoning configurations.

Exceptions: Lighting controls are not required for the following:

  1. Areas designated as security or emergency areas that are required to be continuously lighted.
  2. Interior exit stairways, interior exit ramps and exit passageways.
  3. Emergency egress lighting that is normally off.

Occupant sensor controls shall be installed to control lights in the following space types:

  1. Classrooms/lecture/training rooms.
  2. Conference/meeting/multipurpose rooms.
  3. Copy/print rooms.
  4. Lounges/breakrooms.
  5. Enclosed offices.
  6. Open plan office areas.
  7. Restrooms.
  8. Storage rooms.
  9. Locker rooms.
  10. Other spaces 300 square feet (28 m2) or less that are enclosed by floor-to-ceiling height partitions.
  11. Warehouse storage areas.

Occupant sensor controls in warehouses shall comply with Section C405.2.1.2. Occupant sensor controls in open plan office areas shall comply with Section C405.2.1.3. Occupant sensor controls for all other spaces specified in Section C405.2.1 shall comply with the following:

  1. They shall automatically turn off lights within 20 minutes after all occupants have left the space.
  2. They shall be manual on or controlled to automatically turn on the lighting to not more than 50-percent power.

    Exception: Full automatic-on controls shall be permitted to control lighting in public corridors, stairways, restrooms, primary building entrance areas and lobbies, and areas where manual-on operation would endanger the safety or security of the room or building occupants.

  3. They shall incorporate a manual control to allow occupants to turn off lights.
In warehouses, the lighting in aisleways and open areas shall be controlled with occupant sensors that automatically reduce lighting power by not less than 50 percent when the areas are unoccupied. The occupant sensors shall control lighting in each aisleway independently and shall not control lighting beyond the aisleway being controlled by the sensor.

Occupant sensor controls in open plan office spaces less than 300 square feet (28 m2) in area shall comply with Section C405.2.1.1. Occupant sensor controls in all other open plan office spaces shall comply with all of the following:

  1. The controls shall be configured so that general lighting can be controlled separately in control zones with floor areas not greater than 600 square feet (55 m2) within the open plan office space.
  2. The controls shall automatically turn off general lighting in all control zones within 20 minutes after all occupants have left the open plan office space.
  3. The controls shall be configured so that general lighting power in each control zone is reduced by not less than 80 percent of the full zone general lighting power in a reasonably uniform illumination pattern within 20 minutes of all occupants leaving that control zone. Control functions that switch control zone lights completely off when the zone is vacant meet this requirement.
  4. The controls shall be configured such that any daylight responsive control will activate open plan office space general lighting or control zone general lighting only when occupancy for the same area is detected.

Each area of the building that is not provided with occupant sensor controls complying with Section C405.2.1.1 shall be provided with time-switch controls complying with Section C405.2.2.1.

Exception: Where a manual control provides light reduction in accordance with Section C405.2.2.2, time-switch controls shall not be required for the following:

  1. Spaces where patient care is directly provided.
  2. Spaces where an automatic shutoff would endanger occupant safety or security.
  3. Lighting intended for continuous operation.
  4. Shop and laboratory classrooms.

Each space provided with time-switch controls shall be provided with a manual control for light reduction in accordance with Section C405.2.2.2. Time-switch controls shall include an override switching device that complies with the following:

  1. Have a minimum 7-day clock.
  2. Be capable of being set for seven different day types per week.
  3. Incorporate an automatic holiday “shutoff” feature, which turns off all controlled lighting loads for not fewer than 24 hours and then resumes normally scheduled operations.
  4. Have program backup capabilities, which prevent the loss of program and time settings for not fewer than 10 hours, if power is interrupted.
  5. Include an override switch that complies with the following:

    1. 5.1. The override switch shall be a manual control.
    2. 5.2. The override switch, when initiated, shall permit the controlled lighting to remain on for not more than 2 hours.
    3. 5.3. Any individual override switch shall control the lighting for an area not larger than 5,000 square feet (465 m2).

Exceptions:

  1. Within mall concourses, auditoriums, sales areas, manufacturing facilities and sports arenas:

    1. 1.1. The time limit shall be permitted to be greater than 2 hours, provided that the switch is a captive key device.
    2. 1.2. The area controlled by the override switch shall not be limited to 5,000 square feet (465 m2) provided that such area is less than 20,000 square feet (1860 m2).
  2. Where provided with manual control, the following areas are not required to have light reduction control:

    1. 2.1. Spaces that have only one luminaire with a rated power of less than 100 watts.
    2. 2.2. Spaces that use less than 0.6 watts per square foot (6.5 W/m2).
    3. 2.3. Corridors, lobbies, electrical rooms and or mechanical rooms.

Spaces required to have light-reduction controls shall have a manual control that allows the occupant to reduce the connected lighting load in a reasonably uniform illumination pattern by not less than 50 percent. Lighting reduction shall be achieved by one of the following or another approved method:

  1. Controlling all lamps or luminaires.
  2. Dual switching of alternate rows of luminaires, alternate luminaires or alternate lamps.
  3. Switching the middle lamp luminaires independently of the outer lamps.
  4. Switching each luminaire or each lamp.

    Exception: Light reduction controls are not required in daylight zones with daylight responsive controls complying with Section C405.2.3.

Daylight-responsive controls complying with Section C405.2.3.1 shall be provided to control the electric lights within daylight zones in the following spaces:

  1. Spaces with a total of more than 150 watts of general lighting within sidelit zones complying with Section C405.2.3.2 General lighting does not include lighting that is required to have specific application control in accordance with Section C405.2.4.
  2. Spaces with a total of more than 150 watts of general lighting within toplit zones complying with Section C405.2.3.3.

Exceptions: Daylight responsive controls are not required for the following:

  1. Spaces in health care facilities where patient care is directly provided.
  2. Lighting that is required to have specific application control in accordance with Section C405.2.4.
  3. Sidelit zones on the first floor above grade in Group A-2 and Group M occupancies.
  4. New buildings where the total connected lighting power calculated in accordance with Section C405.3.1 is not greater than the adjusted interior lighting power allowance (LPAadj) calculated in accordance with Equation 4-9

(Equation 4-9)

where:

LPAadj = Adjusted building interior lighting power allowance in watts.

LPAnorm = Normal building lighting power allowance in watts calculated in accordance with Section C405.3.2 and reduced in accordance with Section C406.3 where Option 2 of Section C406.1 is used to comply with the requirements of Section C406.

UDZFA = Uncontrolled daylight zone floor area is the sum of all sidelit and toplit zones, calculated in accordance with Sections C405.2.3.2 and C405.2.3.3, that do not have daylight responsive controls.

TBFA = Total building floor area is the sum of all floor areas included in the lighting power allowance calculation in Section C405.3.2.

Where required, daylight-responsive controls shall be provided within each space for control of lights in that space and shall comply with all of the following:

  1. Lights in toplit zones in accordance with Section C405.2.3.3 shall be controlled independently of lights in sidelit zones in accordance with Section C405.2.3.2.
  2. Daylight responsive controls within each space shall be configured so that they can be calibrated from within that space by authorized personnel.
  3. Calibration mechanisms shall be in a location with ready access.
  4. Where located in offices, classrooms, laboratories and library reading rooms, daylight responsive controls shall dim lights continuously from full light output to 15 percent of full light output or lower.
  5. Daylight responsive controls shall be configured to completely shut off all controlled lights.
  6. Lights in sidelit zones in accordance with Section C405.2.3.2 facing different cardinal orientations [within 45 degrees (0.79 rad) of due north, east, south, west] shall be controlled independently of each other.

Exception: Up to 150 watts of lighting in each space is permitted to be controlled together with lighting in a daylight zone facing a different cardinal orientation.

The sidelit zone is the floor area adjacent to vertical fenestration that complies with all of the following:

  1. Where the fenestration is located in a wall, the sidelit zone shall extend laterally to the nearest full-height wall, or up to 1.0 times the height from the floor to the top of the fenestration, and longitudinally from the edge of the fenestration to the nearest full-height wall, or up to 2 feet (610 mm), whichever is less, as indicated in Figure C405.2.3.2.
  2. The area of the fenestration is not less than 24 square feet (2.23 m2).
  3. The distance from the fenestration to any building or geological formation that would block access to daylight is greater than the height from the bottom of the fenestration to the top of the building or geologic formation.
  4. The visible transmittance of the fenestration is not less than 0.20.

FIGURE C405.2.3.2

SIDELIT ZONE

The toplit zone is the floor area underneath a roof fenestration assembly that complies with all of the following:

  1. The toplit zone shall extend laterally and longitudinally beyond the edge of the roof fenestration assembly to the nearest obstruction that is taller than 0.7 times the ceiling height, or up to 0.7 times the ceiling height, whichever is less, as indicated in Figure C405.2.3.3(1).
  2. Where the fenestration is located in a rooftop monitor, the toplit zone shall extend laterally to the nearest obstruction that is taller than 0.7 times the ceiling height, or up to 1.0 times the height from the floor to the bottom of the fenestration, whichever is less, and longitudinally from the edge of the fenestration to the nearest obstruction that is taller than 0.7 times the ceiling height, or up to 0.25 times the height from the floor to the bottom of the fenestration, whichever is less, as indicated in Figures C405.2.3.3(2) and C405.2.3.3(3).
  3. Direct sunlight is not blocked from hitting the roof fenestration assembly at the peak solar angle on the summer solstice by buildings or geological formations.
  4. The product of the visible transmittance of the roof fenestration assembly and the area of the rough opening of the roof fenestration assembly divided by the area of the toplit zone is not less than 0.008.

FIGURE C405.2.3.3(1)

TOPLIT ZONE

FIGURE C405.2.3.3(2)

DAYLIGHT ZONE UNDER A ROOFTOP MONITOR

FIGURE C405.2.3.3(3)

DAYLIGHT ZONE UNDER A SLOPED ROOFTOP MONITOR

Specific application controls shall be provided for the following:

  1. The following lighting shall be controlled by an occupant sensor complying with Section C405.2.1.1 or a time-switch control complying with Section C405.2.2.1. In addition, a manual control shall be provided to control such lighting separately from the general lighting in the space:

    1. 1.1. Display and accent.
    2. 1.2. Lighting in display cases.
    3. 1.3. Supplemental task lighting, including permanently installed under-shelf or under-cabinet lighting.
    4. 1.4. Lighting equipment that is for sale or demonstration in lighting education.
  2. Sleeping units shall have control devices or systems that are configured to automatically switch off all permanently installed luminaires and switched receptacles within 20 minutes after all occupants have left the unit.

    Exceptions:

    1. Lighting and switched receptacles controlled by card key controls.
    2. Spaces where patient care is directly provided.
  3. Permanently installed luminaires within dwelling units shall be provided with controls complying with Section C405.2.1.1 or C405.2.2.2.
  4. Lighting for nonvisual applications, such as plant growth and food warming, shall be controlled by a time switch control complying with Section C405.2.2.1 that is independent of the controls for other lighting within the room or space.

Where required by this code, manual controls for lights shall comply with the following:

  1. They shall be in a location with ready access to occupants.
  2. They shall be located where the controlled lights are visible, or shall identify the area served by the lights and indicate their status.

Exterior lighting systems shall be provided with controls that comply with Sections C405.2.6.1 through C405.2.6.4. Decorative lighting systems shall comply with Sections C405.2.6.1, C405.2.6.2 and C405.2.6.4.

Exceptions:

  1. Lighting for covered vehicle entrances and exits from buildings and parking structures where required for eye adaptation.
  2. Lighting controlled from within dwelling units.
Lights shall be automatically turned off when daylight is present and satifies the lighting needs.
Building facade and landscape lighting shall automatically shut off from not later than 1 hour after business closing to not earlier than 1 hour before business opening.

Lighting that is not controlled in accordance with Section C405.2.6.2 shall be controlled so that the total wattage of such lighting is automatically reduced by not less than 30 percent by selectively switching off or dimming luminaires at one of the following times:

  1. From not later than midnight to not earlier than 6 a.m.
  2. From not later than one hour after business closing to not earlier than one hour before business opening.
  3. During any time where activity has not been detected for 15 minutes or more.

Time-switch controls for exterior lighting shall comply with the following:

  1. They shall have a clock capable of being programmed for not fewer than 7 days.
  2. They shall be capable of being set for seven different day types per week.
  3. They shall incorporate an automatic holiday setback feature.
  4. They shall have program backup capabilities that prevent the loss of program and time settings for a period of not less than 10 hours in the event that power is interrupted.
A building complies with this section where its total connected interior lighting power calculated under Section C405.3.1 is not greater than the interior lighting power allowance calculated under Section C405.3.2.

The total connected interior lighting power shall be determined in accordance with Equation 4-10.

(Equation 4-10)

where:

TCLP = Total connected lighting power (watts).

LVL = For luminaires with lamps connected directly to building power, such as line voltage lamps, the rated wattage of the lamp.

BLL = For luminaires incorporating a ballast or transformer, the rated input wattage of the ballast or transformer when operating that lamp.

LED = For light-emitting diode luminaires with either integral or remote drivers, the rated wattage of the luminaire.

TRK = For lighting track, cable conductor, rail conductor, and plug-in busway systems that allow the addition and relocation of luminaires without rewiring, the wattage shall be one of the following:

  1. The specified wattage of the luminaires, but not less than 8 W per linear foot (25 W/lin m).
  2. The wattage limit of the permanent current-limiting devices protecting the system.
  3. The wattage limit of the transformer supplying the system.

Other = The wattage of all other luminaires and lighting sources not covered previously and associated with interior lighting verified by data supplied by the manufacturer or other approved sources.

The connected power associated with the following lighting equipment and applications is not included in calculating total connected lighting power.

  1. Television broadcast lighting for playing areas in sports arenas.
  2. Emergency lighting automatically off during normal building operation.
  3. Lighting in spaces specifically designed for use by occupants with special lighting needs, including those with visual impairment and other medical and age-related issues.
  4. Casino gaming areas.
  5. Mirror lighting in dressing rooms.
  6. Task lighting for medical and dental purposes that is in addition to general lighting and controlled by an independent control device.
  7. Display lighting for exhibits in galleries, museums and monuments that is in addition to general lighting and controlled by an independent control device.
  8. Lighting for theatrical purposes, including performance, stage, film production and video production.
  9. Lighting for photographic processes.
  10. Lighting integral to equipment or instrumentation and installed by the manufacturer.
  11. Task lighting for plant growth or maintenance.
  12. Advertising signage or directional signage.
  13. Lighting for food warming.
  14. Lighting equipment that is for sale.
  15. Lighting demonstration equipment in lighting education facilities.
  16. Lighting approved because of safety considerations.
  17. Lighting in retail display windows, provided that the display area is enclosed by ceiling-height partitions.
  18. Furniture-mounted supplemental task lighting that is controlled by automatic shutoff.
  19. Exit signs.

The total interior lighting power allowance (watts) is determined according to Table C405.3.2(1) using the Building Area Method, or Table C405.3.2(2) using the Space-by-Space Method, for all areas of the building covered in this permit.

TABLE C405.3.2(1)

INTERIOR LIGHTING POWER ALLOWANCES: BUILDING AREA METHOD

BUILDING AREA TYPELPD (w/ft2)
Automotive facility0.71
Convention center0.76
Courthouse0.90
Dining: bar lounge/leisure0.90
Dining: cafeteria/fast food0.79
Dining: family0.78
Dormitorya, b0.61
Exercise center0.65
Fire stationa0.53
Gymnasium0.68
Health care clinic0.82
Hospitala1.05
Hotel/Motela, b0.75
Library0.78
Manufacturing facility0.90
Motion picture theater0.83
Multifamilyc0.68
Museum1.06
Office0.79
Parking garage0.15
Penitentiary0.75
Performing arts theater1.18
Police station0.80
Post office0.67
Religious building0.94
Retail1.06
School/university0.81
Sports arena0.87
Town hall0.80
Transportation0.61
Warehouse0.48
Workshop0.90
  1. Where sleeping units are excluded from lighting power calculations by application of Section R405.1, neither the area of the sleeping units nor the wattage of lighting in the sleeping units is counted.
  2. Where dwelling units are excluded from lighting power calculations by application of Section R405.1, neither the area of the dwelling units nor the wattage of lighting in the dwelling units is counted.
  3. Dwelling units are excluded. Neither the area of the dwelling units nor the wattage of lighting in the dwelling units is counted.

TABLE C405.3.2(2)

INTERIOR LIGHTING POWER ALLOWANCES: SPACE-BY-SPACE METHOD

COMMON SPACE TYPESaLPD (watts/sq.ft)
Atrium
Less than 40 feet in height0.03 per foot
in total height
Greater than 40 feet in height0.40 + 0.02 per foot
in total height
Audience seating area
In an auditorium0.63
In a convention center0.82
In a gymnasium0.65
In a motion picture theater1.14
In a penitentiary0.28
In a performing arts theater2.03
In a religious building1.53
In a sports arena0.43
Otherwise0.43
Banking activity area0.86
Breakroom (See Lounge/breakroom)
Classroom/lecture hall/training room
In a penitentiary1.34
Otherwise0.96
Computer room1.33
Conference/meeting/multipurpose room1.07
Copy/print room0.56
Corridor
In a facility for the visually impaired (and
not used primarily by the staff)b
0.92
In a hospital0.92
In a manufacturing facility0.29
Otherwise0.66
Courtroom1.39
Dining area
In bar/lounge or leisure dining0.93
In cafeteria or fast food dining0.63
In a facility for the visually impaired (and
not used primarily by the staff)b
2.00
In family dining0.71
In a penitentiary0.96
Otherwise0.63
Electrical/mechanical room0.43
Emergency vehicle garage0.41
Food preparation area1.06
Guestroomc, d0.77
Laboratory
In or as a classroom1.20
Otherwise1.45
Laundry/washing area0.43
Loading dock, interior0.58
Lobby
For an elevator0.68
In a facility for the visually impaired (and
not used primarily by the staff)b
2.03
In a hotel1.06
In a motion picture theater0.45
In a performing arts theater1.70
Otherwise1.0
Locker room0.48
Lounge/breakroom
In a healthcare facility0.78
Otherwise0.62
Office
Enclosed0.93
Open plan0.81
Parking area, interior0.14
Pharmacy area1.34
Restroom
In a facility for the visually impaired (and
not used primarily by the staffb
0.96
Otherwise0.85
Sales area1.22
Seating area, general0.42
Stairway (see Space containing stairway)
Stairwell0.58
Storage room0.46
Vehicular maintenance area0.56
Workshop1.14
BUILDING TYPE SPECIFIC SPACE TYPESaLPD (watts/sq.ft)
Automotive (see Vehicular maintenance area)
Convention Center—exhibit space0.88
Dormitory—living quartersc, d0.54
Facility for the visually impairedb
In a chapel (and not used primarily by the
staff)
1.06
In a recreation room (and not used primarily
by the staff)
1.80
Fire Station—sleeping quartersc0.20
Gymnasium/fitness center
In an exercise area0.50
In a playing area0.82
Healthcare facility
In an exam/treatment room1.68
In an imaging room1.06
In a medical supply room0.54
In a nursery1.00
In a nurse’s station0.81
In an operating room2.17
In a patient roomc0.62
In a physical therapy room0.84
In a recovery room1.03
Library
In a reading area0.82
In the stacks1.20
Manufacturing facility
In a detailed manufacturing area0.93
In an equipment room0.65
In an extra-high-bay area (greater than 50'
floor-to-ceiling height)
1.05
In a high-bay area (25-50’
floor-to-ceiling height)
0.75
In a low-bay area (less than 25’ floor-to-
ceiling height)
0.96
Museum
In a general exhibition area1.05
In a restoration room0.85
Performing arts theater—dressing room0.36
Post office—sorting area0.68
Religious buildings
In a fellowship hall0.55
In a worship/pulpit/choir area1.53
Retail facilities
In a dressing/fitting room0.50
In a mall concourse0.90
Sports arena—playing area
For a Class I facilitye2.47
For a Class II facilityf1.96
For a Class III facilityg1.70
For a Class IV facilityh1.13
Transportation facility
In a baggage/carousel area0.45
In an airport concourse0.31
At a terminal ticket counter0.62
Warehouse—storage area
For medium to bulky, palletized items0.35
For smaller, hand-carried items0.69
  1. In cases where both a common space type and a building area specific space type are listed, the building area specific space type shall apply
  2. A 'Facility for the Visually Impaired’ is a facility that is licensed or will be licensed by local or state authorities for senior long-term care, adult daycare, senior support or people with special visual needs.
  3. Where sleeping units are excluded from lighting power calculations by application of Section R405.1, neither the area of the sleeping units nor the wattage of lighting in the sleeping units is counted.
  4. Where dwelling units are excluded from lighting power calculations by application of Section R405.1, neither the area of the dwelling units nor the wattage of lighting in the dwelling units is counted.
  5. Class I facilities consist of professional facilities; and semiprofessional, collegiate, or club facilities with seating for 5,000 or more spectators.
  6. Class II facilities consist of collegiate and semiprofessional facilities with seating for fewer than 5,000 spectators; club facilities with seating for between 2,000 and 5,000 spectators; and amateur league and high-school facilities with seating for more than 2,000 spectators.
  7. Class III facilities consist of club, amateur league and high-school facilities with seating for 2,000 or fewer spectators.
  8. Class IV facilities consist of elementary school and recreational facilities; and amateur league and high-school facilities without provision for spectators.
For the Building Area Method, the interior lighting power allowance is the floor area for each building area type listed in Table C405.3.2(1) times the value from Table C405.3.2(1) for that area. For the purposes of this method, an “area” shall be defined as all contiguous spaces that accommodate or are associated with a single building area type, as listed in Table C405.3.2(1). Where this method is used to calculate the total interior lighting power for an entire building, each building area type shall be treated as a separate area.
For the Space-by-Space Method, the interior lighting power allowance is determined by multiplying the floor area of each space times the value for the space type in Table C405.3.2(2) that most closely represents the proposed use of the space, and then summing the lighting power allowances for all spaces. Tradeoffs among spaces are permitted.

Where using the Space-by-Space Method, an increase in the interior lighting power allowance is permitted for specific lighting functions. Additional power shall be permitted only where the specified lighting is installed and automatically controlled separately from the general lighting, to be turned off during nonbusiness hours. This additional power shall be used only for the specified luminaires and shall not be used for any other purpose. An increase in the interior lighting power allowance is permitted in the following cases:

  1. For lighting equipment to be installed in sales areas specifically to highlight merchandise, the additional lighting power shall be determined in accordance with Equation 4-11.

    Additional interior lighting power allowance = 1000 W + (Retail Area 1 x 0.45 W/ft2) + (Retail Area 2 x 0.45W/ft2) + (Retail Area 3 x 1.05 W/ft2) + (Retail Area 4 x 1.87 W/ft2)

    For SI units:

    (Equation 4-11)

    where:

    Retail Area 1 = The floor area for all products not listed in Retail Area 2, 3 or 4.

    Retail Area 2 = The floor area used for the sale of vehicles, sporting goods and small electronics.

    Retail Area 3 = The floor area used for the sale of furniture, clothing, cosmetics and artwork.

    Retail Area 4 = The floor area used for the sale of jewelry, crystal and china.

    Exception: Other merchandise categories are permitted to be included in Retail Areas 2 through 4, provided that justification documenting the need for additional lighting power based on visual inspection, contrast, or other critical display is approved by the code official.

  2. For spaces in which lighting is specified to be installed in addition to the general lighting for the purpose of decorative appearance or for highlighting art or exhibits, provided that the additional lighting power shall be not more than 0.9 W/ft2 (9.7 W/m2) in lobbies and not more than 0.75 W/ft2 (8.1 W/m2) in other spaces.
The total connected exterior lighting power calculated in accordance with Section C405.4.1 shall be not greater than the exterior lighting power allowance calculated in accordance with Section C405.4.2.

The total exterior connected lighting power shall be the total maximum rated wattage of all lighting that is powered through the energy service for the building.

Exception: Lighting used for the following applications shall not be included.

  1. Lighting approved because of safety considerations.
  2. Emergency lighting automatically off during normal business operation.
  3. Exit signs.
  4. Specialized signal, directional and marker lighting associated with transportation.
  5. Advertising signage or directional signage.
  6. Integral to equipment or instrumentation and installed by its manufacturer.
  7. Theatrical purposes, including performance, stage, film production and video production.
  8. Athletic playing areas.
  9. Temporary lighting.
  10. Industrial production, material handling, transportation sites and associated storage areas.
  11. Theme elements in theme/amusement parks.
  12. Used to highlight features of art, public monuments, and the national flag.
  13. Lighting for water features and swimming pools.
  14. Lighting controlled from within dwelling units, where the lighting complies with Section R404.1.

The total exterior lighting power allowance is the sum of the base site allowance plus the individual allowances for areas that are to be illuminated by lighting that is powered through the energy service for the building. Lighting power allowances are as specified in Table C405.4.2(2). The lighting zone for the building exterior is determined in accordance with Table C405.4.2(1) unless otherwise specified by the code official.

TABLE C405.4.2(1)

EXTERIOR LIGHTING ZONES

LIGHTING
ZONE
DESCRIPTION
1Developed areas of national parks, state parks, forest
land, and rural areas
2Areas predominantly consisting of residential zoning,
neighborhood business districts, light industrial with
limited nighttime use and residential mixed-use areas
3All other areas not classified as lighting zone 1, 2 or 4
4High-activity commercial districts in major metropolitan
areas as designated by the local land use planning
authority

TABLE C405.4.2(2)

LIGHTING POWER ALLOWANCES FOR BUILDING EXTERIORS

    LIGHTING ZONES
  Zone 1 Zone 2 Zone 3 Zone 4
  Base Site Allowance 350 W 400 W 500 W 900 W
  Uncovered Parking Areas
  Parking areas and drives 0.03W/ft2 0.04 W/ft2 0.06 W/ft2 0.08 W/ft2
  Building Grounds
  Walkways and ramps less
than 10 feet wide
0.5 W/linear foot 0.5 W/linear foot 0.6 W/linear foot 0.7 W/linear foot
  Walkways and ramps 10
feet wide or greater,
plaza areas, special
feature areas
0.10 W/ft2 0.10 W/ft2 0.11 W/ft2 0.14 W/ft2
  Dining areas 0.65 W/ft2 0.65 W/ft2 0.75 W/ft2 0.95 W/ft2
  Stairways 0.6 W/ft2 0.7 W/ft2 0.7 W/ft2 0.7 W/ft2
  Pedestrian tunnels 0.12 W/ft2 0.12 W/ft2 0.14 W/ft2 0.21 W/ft2
  Landscaping 0.03 W/ft2 0.04 W/ft2 0.04 W/ft2 0.04 W/ft2
  Building Entrances and Exits
  Pedestrian and vehicular
entrances and exits
14 W/linear foot
of opening
14 W/linear foot
of opening
21 W/linear foot
of opening
21 W/linear foot
of opening
  Entry canopies 0.20 W/ft2 0.25 W/ft2 0.4 W/ft2 0.4 W/ft2
  Loading docks 0.35 W/ft2 0.35 W/ft2 0.35 W/ft2 0.35 W/ft2
  Sales Canopies
  Free-standing and
attached
0.40 W/ft2 0.40 W/ft2 0.6 W/ft2 0.7 W/ft2
  Outdoor Sales
  Open areas (including
vehicle sales lots)
0.20 W/ft2 0.20 W/ft2 0.35 W/ft2 0.50 W/ft2
  Street frontage for
vehicle sales lots in
addition to “open area”
allowance
No allowance 7 W/linear foot 7 W/linear foot 21 W/linear foot

For SI: 1 foot = 304.8 mm, 1 watt per square foot = W/0.0929 m2.

W = watts.

TABLE C405.4.2(3)

INDIVIDUAL LIGHTING POWER ALLOWANCES FOR BUILDING EXTERIORS

LIGHTING ZONES
Zone 1Zone 2Zone 3Zone 4
Building facadesNo allowance0.075 W/ft2 of gross
above-grade wall area
0.113 W/ft2 of gross
above-grade wall area
0.15 W/ft2 of gross
above-grade wall area
Automated teller machines (ATM) and
night depositories
135 W per location plus 45 W per additional ATM per location
Uncovered entrances and gatehouse
inspection stations at guarded facilities
0.5 W/ft2 of area
Uncovered loading areas for law
enforcement, fire, ambulance and other
emergency service vehicles
0.35 W/ft2 of area
Drive-up windows and doors200 W per drive through
Parking near 24-hour retail entrances.400 W per main entry

For SI: For SI: 1 watt per square foot = W/0.0929 m2.

W = watts.

Any increase in the exterior lighting power allowance is limited to the specific lighting applications indicated in Table C405.4.2(3). The additional power shall be used only for the luminaires that are serving these applications and shall not be used for any other purpose.
Gas-fired lighting appliances shall not be equipped with continuously burning pilot ignition systems.
Each dwelling unit located in a Group R-2 building shall have a separate electrical meter.

Low-voltage dry-type distribution electric transformers shall meet the minimum efficiency requirements of Table C405.6 as tested and rated in accordance with the test procedure listed in DOE 10 CFR 431. The efficiency shall be verified through certification under an approved certification program or, where a certification program does not exist, the equipment efficiency ratings shall be supported by data furnished by the transformer manufacturer.

Exceptions: The following transformers are exempt:

  1. Transformers that meet the Energy Policy Act of 2005 exclusions based on the DOE 10 CFR 431 definition of special purpose applications.
  2. Transformers that meet the Energy Policy Act of 2005 exclusions that are not to be used in general purpose applications based on information provided in DOE 10 CFR 431.
  3. Transformers that meet the Energy Policy Act of 2005 exclusions with multiple voltage taps where the highest tap is not less than 20 percent more than the lowest tap.
  4. Drive transformers.
  5. Rectifier transformers.
  6. Auto-transformers.
  7. Uninterruptible power system transformers.
  8. Impendance transformers.
  9. Regulating transformers.
  10. Sealed and nonventilating transformers.
  11. Machine tool transformers.
  12. Welding transformers.
  13. Grounding transformers.
  14. Testing transformers.

TABLE C405.6

MINIMUM NOMINAL EFFICIENCY LEVELS FOR 10 CFR 431 LOW-VOLTAGE DRY-TYPE DISTRIBUTION TRANSFORMERS

SINGLE-PHASE TRANSFORMERSTHREE-PHASE TRANSFORMERS
kVAaEfficiency (%)bkVAaEfficiency (%)b
1597.701597.89
2598.003098.23
37.598.204598.40
5098.307598.60
7598.50112.598.74
10098.6015098.83
16798.7022598.94
25098.8030099.02
33398.9050099.14
75099.23
100099.28
  1. kiloVolt-Amp rating.
  2. Nominal efficiencies shall be established in accordance with the DOE 10 CFR 431 test procedure for low-voltage dry-type transformers.

Electric motors shall meet the minimum efficiency requirements of Tables C405.7(1) through C405.7(4) when tested and rated in accordance with the DOE 10 CFR 431. The efficiency shall be verified through certification under an approved certification program or, where a certification program does not exist, the equipment efficiency ratings shall be supported by data furnished by the motor manufacturer.

Exception: The standards in this section shall not apply to the following exempt electric motors:

  1. Air-over electric motors.
  2. Component sets of an electric motor.
  3. Liquid-cooled electric motors.
  4. Submersible electric motors.
  5. Inverter-only electric motors.

TABLE C405.7(1)

MINIMUM NOMINAL FULL-LOAD EFFICIENCY FOR NEMA DESIGN A, NEMA DESIGN B, AND IEC DESIGN N MOTORS (EXCLUDING FIRE PUMP) ELECTRIC MOTORS AT 60 HZa, b

MOTOR HORSEPOWER
(STANDARD KILOWATT EQUIVALENT)
NOMINAL FULL-LOAD EFFICIENCY (%) AS OF JUNE 1, 2016
2 Pole4 Pole6 Pole8 Pole
EnclosedOpenEnclosedOpenEnclosedOpenEnclosedOpen
1 (0.75)77.077.085.585.582.582.575.575.5
1.5 (1.1)84.084.086.586.587.586.578.577.0
2 (1.5)85.585.586.586.588.587.584.086.5
3 (2.2)86.585.589.589.589.588.585.587.5
5 (3.7)88.586.589.589.589.589.586.588.5
7.5 (5.5)89.588.591.791.091.090.286.589.5
10 (7.5)90.289.591.791.791.091.789.590.2
15 (11)91.090.292.493.091.791.789.590.2
20 (15)91.091.093.093.091.792.490.291.0
25 (18.5)91.791.793.693.693.093.090.291.0
30 (22)91.791.793.694.193.093.691.791.7
40 (30)92.492.494.194.194.194.191.791.7
50 (37)93.093.094.594.594.194.192.492.4
60 (45)93.693.695.095.094.594.592.493.0
75 (55)93.693.695.495.094.594.593.694.1
100 (75)94.193.695.495.495.095.093.694.1
125 (90)95.094.195.495.495.095.094.194.1
150 (110)95.094.195.895.895.895.494.194.1
200 (150)95.495.096.295.895.895.494.594.1
250 (186)95.895.096.295.895.895.895.095.0
300 (224)95.895.496.295.895.895.8
350 (261)95.895.496.295.895.895.8
400 (298)95.895.896.295.8
450 (336)95.896.296.296.2
500 (373)95.896.296.296.2
  1. Nominal efficiencies shall be established in accordance with DOE 10 CFR 431.
  2. For purposes of determining the required minimum nominal full-load efficiency of an electric motor that has a horsepower or kilowatt rating between two horsepower or two kilowatt ratings listed in this table, each such motor shall be deemed to have a listed horsepower or kilowatt rating, determined as follows:

    1. A horsepower at or above the midpoint between the two consecutive horsepowers shall be rounded up to the higher of the two horsepowers.
    2. A horsepower below the midpoint between the two consecutive horsepowers shall be rounded down to the lower of the two horsepowers.
    3. A kilowatt rating shall be directly converted from kilowatts to horsepower using the formula: 1 kilowatt = (1/0.746) horsepower. The conversion should be calculated to three significant decimal places, and the resulting horsepower shall be rounded in accordance with No. 1 or No. 2 above, as applicable.

TABLE C405.7(2)

MINIMUM NOMINAL FULL-LOAD EFFICIENCY FOR NEMA DESIGN C AND IEC DESIGN H MOTORS AT 60 HZa, b

MOTOR HORSEPOWER
(STANDARD KILOWATT EQUIVALENT)
NOMINAL FULL-LOAD EFFICIENCY (%) AS OF JUNE 1, 2016
4 Pole6 Pole8 Pole
EnclosedOpenEnclosedOpenEnclosedOpen
1 (0.75)85.585.582.582.575.575.5
1.5 (1.1)86.586.587.586.578.577.0
2 (1.5)86.586.588.587.584.086.5
3 (2.2)89.589.589.588.585.587.5
5 (3.7)89.589.589.589.586.588.5
7.5 (5.5)91.791.091.090.286.589.5
10 (7.5)91.791.791.091.789.590.2
15 (11)92.493.091.791.789.590.2
20 (15)93.093.091.792.490.291.0
25 (18.5)93.693.693.093.090.291.0
30 (22)93.694.193.093.691.791.7
40 (30)94.194.194.194.191.791.7
50 (37)94.594.594.194.192.492.4
60 (45)95.095.094.594.592.493.0
75 (55)95.495.094.594.593.694.1
100 (75)95.495.495.095.093.694.1
125 (90)95.495.495.095.094.194.1
150 (110)95.895.895.895.494.194.1
200 (150)96.295.895.895.494.594.1
  1. Nominal efficiencies shall be established in accordance with DOE 10 CFR 431.
  2. For purposes of determining the required minimum nominal full-load efficiency of an electric motor that has a horsepower or kilowatt rating between two horsepower or two kilowatt ratings listed in this table, each such motor shall be deemed to have a listed horsepower or kilowatt rating, determined as follows:

    1. A horsepower at or above the midpoint between the two consecutive horsepowers shall be rounded up to the higher of the two horsepowers.
    2. A horsepower below the midpoint between the two consecutive horsepowers shall be rounded down to the lower of the two horsepowers.
    3. A kilowatt rating shall be directly converted from kilowatts to horsepower using the formula: 1 kilowatt = (1/0.746) horsepower. The conversion should be calculated to three significant decimal places, and the resulting horsepower shall be rounded in accordance with No. 1 or No. 2 above, as applicable.

TABLE C405.7(3)

MINIMUM AVERAGE FULL-LOAD EFFICIENCY POLYPHASE SMALL ELECTRIC MOTORSa

MOTOR
HORSEPOWER
OPEN MOTORS
Number of Poles246
Synchronous
Speed (RPM)
360018001200
0.2565.669.567.5
0.3369.573.471.4
0.5073.478.275.3
0.7576.881.181.7
177.083.582.5
1.584.086.583.8
285.586.5N/A
385.586.9N/A
  1. Average full-load efficiencies shall be established in accordance with DOE 10 CFR 431.

TABLE C405.7(4)

MINIMUM AVERAGE FULL-LOAD EFFICIENCY FOR CAPACITOR-START CAPACITOR-RUN AND CAPACITOR-START INDUCTION-RUN SMALL ELECTRIC MOTORSa

MOTOR
HORSEPOWER
OPEN MOTORS
Number of Poles246
Synchronous
Speed (RPM)
360018001200
0.2566.668.562.2
0.3370.572.466.6
0.5072.476.276.2
0.7576.281.880.2
180.482.681.1
1.581.583.8N/A
282.984.5N/A
384.1N/AN/A
  1. Average full-load efficiencies shall be established in accordance with DOE 10 CFR 431.
Vertical and horizontal transportation systems and equipment shall comply with this section.
For the luminaires in each elevator cab, not including signals and displays, the sum of the lumens divided by the sum of the watts shall be not less than 35 lumens per watt. Ventilation fans in elevators that do not have their own air-conditioning system shall not consume more than 0.33 watts/cfm at the maximum rated speed of the fan. Controls shall be provided that will de-energize ventilation fans and lighting systems when the elevator is stopped, unoccupied and with its doors closed for over 15 minutes.

Escalators and moving walks shall comply with ASME A17.1/CSA B44 and shall have automatic controls configured to reduce speed to the minimum permitted speed in accordance with ASME A17.1/CSA B44 or applicable local code when not conveying passengers.

Exception: A variable voltage drive system that reduces operating voltage in response to light loading conditions is an alternative to the reduced speed function.

An escalator designed either for one-way down operation only or for reversible operation shall have a variable frequency regenerative drive that supplies electrical energy to the building electrical system when the escalator is loaded with passengers whose combined weight exceeds 750 pounds (340 kg).
The total voltage drop across the combination of feeders and branch circuits shall not exceed 5 percent.

Buildings shall comply with one or more of the following:

  1. More efficient HVAC performance in accordance with Section C406.2.
  2. Reduced lighting power in accordance with Section C406.3.
  3. Enhanced lighting controls in accordance with Section C406.4.
  4. On-site supply of renewable energy in accordance with Section C406.5.
  5. Provision of a dedicated outdoor air system for certain HVAC equipment in accordance with Section C406.6.
  6. High-efficiency service water heating in accordance with Section C406.7.
  7. Enhanced envelope performance in accordance with Section C406.8.
  8. Reduced air infiltration in accordance with Section C406.9

Tenant spaces shall comply with Section C406.2, C406.3, C406.4, C406.6 or C406.7. Alternatively, tenant spaces shall comply with Section C406.5 where the entire building is in compliance.

Exception: Previously occupied tenant spaces that comply with this code in accordance with Section C501.

Equipment shall exceed the minimum efficiency requirements listed in Tables C403.3.2(1) through C403.3.2(7) by 10 percent, in addition to the requirements of Section C403. Where multiple performance requirements are provided, the equipment shall exceed all requirements by 10 percent. Variable refrigerant flow systems shall exceed the energy efficiency provisions of ANSI/ASHRAE/IESNA 90.1 by 10 percent. Equipment not listed in Tables C403.3.2(1) through C403.3.2(7) shall be limited to 10 percent of the total building system capacity.
The total connected interior lighting power calculated in accordance with Section C405.3.1 shall be less than 90 percent of the total lighting power allowance calculated in accordance with Section C405.3.2.

Interior lighting in the building shall have the following enhanced lighting controls that shall be located, scheduled and operated in accordance with Sections C405.2.1 through C405.2.3.

  1. Luminaires shall be configured for continuous dimming.
  2. Luminaires shall be addressed individually. Where individual addressability is not available for the luminaire class type, a controlled group of not more than four luminaries shall be allowed.
  3. Not more than eight luminaires shall be controlled together in a daylight zone.
  4. Fixtures shall be controlled through a digital control system that includes the following function:
    1. Control reconfiguration based on digital addressability.
    2. Load shedding.
    3. Individual user control of overhead general illumination in open offices.
    4. Occupancy sensors shall be capable of being reconfigured through the digital control system.
  5. Construction documents shall include submittal of a Sequence of Operations, including a specification outlining each of the functions in Item 4.
  6. Functional testing of lighting controls shall comply with Section C408.

The total minimum ratings of on-site renewable energy systems shall be one of the following:

  1. Not less than 1.71 Btu/h per square foot (5.4 W/m2) or 0.50 watts per square foot (5.4 W/m2) of conditioned floor area.
  2. Not less than 3 percent of the energy used within the building for building mechanical and service water heating equipment and lighting regulated in Chapter 4.
Buildings containing equipment or systems regulated by Section C403.3.4, C403.4.3, C403.4.4, C403.4.5, C403.6, C403.8.4, C403.8.5, C403.8.5.1, C403.9.1, C403.9.2, C403.9.3 or C403.9.4 shall be equipped with an independent ventilation system designed to provide not less than the minimum 100-percent outdoor air to each individual occupied space, as specified by the International Mechanical Code. The ventilation system shall be capable of total energy recovery. The HVAC system shall include supply-air temperature controls that automatically reset the supply-air temperature in response to representative building loads, or to outdoor air temperatures. The controls shall reset the supply-air temperature not less than 25 percent of the difference between the design supply-air temperature and the design room-air temperature.

Buildings shall be of the following types to use this compliance method:

  1. Group R-1: Boarding houses, hotels or motels.
  2. Group I-2: Hospitals, psychiatric hospitals and nursing homes.
  3. Group A-2: Restaurants and banquet halls or buildings containing food preparation areas.
  4. Group F: Laundries.
  5. Group R-2.
  6. Group A-3: Health clubs and spas.
  7. Buildings showing a service hot water load of 10 percent or more of total building energy loads, as shown with an energy analysis as described in Section C407.

The building service water-heating system shall have one or more of the following that are sized to provide not less than 60 percent of the building’s annual hot water requirements, or sized to provide 100 percent of the building’s annual hot water requirements if the building shall otherwise comply with Section C403.9.5:

  1. Waste heat recovery from service hot water, heat-recovery chillers, building equipment, or process equipment.
  2. On-site renewable energy water-heating systems.
The total UA of the building thermal envelope as designed shall be not less than 15 percent below the total UA of the building thermal envelope in accordance with Section C402.1.5.

Air infiltration shall be verified by whole-building pressurization testing conducted in accordance with ASTM E779 or ASTM E1827 by an independent third party. The measured air-leakage rate of the building envelope shall not exceed 0.25 cfm/ft2 (2.0 L/s x m2) under a pressure differential of 0.3 inches water column (75 Pa), with the calculated surface area being the sum of the above- and below-grade building envelope. A report that includes the tested surface area, floor area, air by volume, stories above grade, and leakage rates shall be submitted to the code official and the building owner.

Exception: For buildings having over 250,000 square feet (25 000 m2) of conditioned floor area, air leakage testing need not be conducted on the whole building where testing is conducted on representative above-grade sections of the building. Tested areas shall total not less than 25 percent of the conditioned floor area and shall be tested in accordance with this section.

This section establishes criteria for compliance using total building performance. The following systems and loads shall be included in determining the total building performance: heating systems, cooling systems, service water heating, fan systems, lighting power, receptacle loads and process loads.

Exception: Energy used to recharge or refuel vehicles that are used for on-road and off-site transportation purposes.

Compliance with this section requires compliance with Sections C402.5, C403.2, C403.3 through C403.3.2, C403.4 through C403.4.2.3, C403.5.5, C403.7, C403.8.1 through C403.8.4, C403.10.1 through C403.10.3, C403.11, C403.12, C404 and C405.

Compliance based on total building performance requires that a proposed building (proposed design) be shown to have an annual energy cost that is less than or equal to the annual energy cost of the standard reference design. Energy prices shall be taken from a source approved by the code official, such as the Department of Energy, Energy Information Administration’s State Energy Price and Expenditure Report. Code officials shall be permitted to require time-of-use pricing in energy cost calculations. The reduction in energy cost of the proposed design associated with on-site renewable energy shall be not more than 5 percent of the total energy cost. The amount of renewable energy purchased from off-site sources shall be the same in the standard reference design and the proposed design.

Exception: Jurisdictions that require site energy (1 kWh = 3413 Btu) rather than energy cost as the metric of comparison.

Documentation verifying that the methods and accuracy of compliance software tools conform to the provisions of this section shall be provided to the code official.

Permit submittals shall include a report documenting that the proposed design has annual energy costs less than or equal to the annual energy costs of the standard reference design. The compliance documentation shall include the following information:

  1. Address of the building.
  2. An inspection checklist documenting the building component characteristics of the proposed design as specified in Table C407.5.1(1). The inspection checklist shall show the estimated annual energy cost for both the standard reference design and the proposed design.
  3. Name of individual completing the compliance report.
  4. Name and version of the compliance software tool.

The code official shall be permitted to require the following documents:

  1. Documentation of the building component characteristics of the standard reference design.
  2. Thermal zoning diagrams consisting of floor plans showing the thermal zoning scheme for standard reference design and proposed design.
  3. Input and output reports from the energy analysis simulation program containing the complete input and output files, as applicable. The output file shall include energy use totals and energy use by energy source and end-use served, total hours that space conditioning loads are not met and any errors or warning messages generated by the simulation tool as applicable.
  4. An explanation of any error or warning messages appearing in the simulation tool output.
  5. A certification signed by the builder providing the building component characteristics of the proposed design as given in Table C407.5.1(1).
  6. Documentation of the reduction in energy use associated with on-site renewable energy.
Except as specified by this section, the standard reference design and proposed design shall be configured and analyzed using identical methods and techniques.

The standard reference design and proposed design shall be configured and analyzed as specified by Table C407.5.1(1). Table C407.5.1(1) shall include by reference all notes contained in Table C402.1.4.

TABLE C407.5.1(1)

SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS

BUILDING COMPONENT
CHARACTERISTICS
STANDARD REFERENCE DESIGNPROPOSED DESIGN
Space use classificationSame as proposedThe space use classification shall be chosen in
accordance with Table C405.5.2 for all areas of the
building covered by this permit. Where the space use
classification for a building is not known, the building
shall be categorized as an office building.
RoofsType: Insulation entirely above deckAs proposed
Gross area: same as proposedAs proposed
U-factor: as specified in Table C402.1.4As proposed
Solar absorptance: 0.75As proposed
Emittance: 0.90As proposed
Walls, above-gradeType: Mass wall where proposed wall is mass; otherwise steel-framed
wall
As proposed
Gross area: same as proposedAs proposed
U-factor: as specified in Table C402.1.4As proposed
Solar absorptance: 0.75As proposed
Emittance: 0.90As proposed
Walls, below-gradeType: Mass wallAs proposed
Gross area: same as proposedAs proposed
U-Factor: as specified in Table C402.1.4 with insulation layer on interior
side of walls
As proposed
Floors, above-gradeType: joist/framed floorAs proposed
Gross area: same as proposedAs proposed
U-factor: as specified in Table C402.1.4As proposed
Floors, slab-on-gradeType: UnheatedAs proposed
F-factor: as specified in Table C402.1.4As proposed
Opaque doorsType: SwingingAs proposed
Area: Same as proposedAs proposed
U-factor: as specified in Table C402.1.4As proposed
Vertical fenestration other than
opaque doors
Area
  1. The proposed vertical fenestration area; where the proposed vertical fenestration area is less than 40 percent of above-grade wall area.
  2. 40 percent of above-grade wall area; where the proposed vertical fenestration area is 40 percent or more of the above-grade wall area.
As proposed
U-factor: as specified in Table C402.4As proposed
SHGC: as specified in Table C402.4 except that for climates with no
requirement (NR) SHGC = 0.40 shall be used
As proposed
External shading and PF: NoneAs proposed
SkylightsArea
  1. The proposed skylight area; where the proposed skylight area is less than that permitted by Section C402.1.
  2. The area permitted by Section C402.1; where the proposed skylight area exceeds that permitted by Section C402.1
As proposed
U-factor: as specified in Table C402.4As proposed
SHGC: as specified in Table C402.4 except that for climates with no
requirement (NR) SHGC = 0.40 shall be used.
As proposed
Lighting, interiorThe interior lighting power shall be determined in accordance with
Section C405.3.2. Where the occupancy of the building is not known,
the lighting power density shall be 1.0 Watt per square foot (10.7 W/
m2) based on the categorization of buildings with unknown space
classification as offices.
As proposed
Lighting, exteriorThe lighting power shall be determined in accordance with
Table C405.4.2(2) and C405.4.2(3). Areas and dimensions of surfaces
shall be the same as proposed.
As proposed
Internal gainsSame as proposedReceptacle, motor and process loads shall be
modeled and estimated based on the space use
classification. End-use load components within and
associated with the building shall be modeled to
include, but not be limited to, the following:
exhaust fans, parking garage ventilation fans,
exterior building lighting, swimming pool heaters
and pumps, elevators, escalators, refrigeration
equipment and cooking equipment.
SchedulesSame as proposed

Exception: Thermostat settings and schedules for HVAC systems that utilize radiant heating, radiant cooling and elevated air speed, provided that equivalent levels of occupant thermal comfort are demonstrated by means of equal Standard Effective Temperature as calculated in Normative Appendix B of ASHRAE Standard 55.

Operating schedules shall include hourly profiles
for daily operation and shall account for variations
between weekdays, weekends, holidays and any
seasonal operation. Schedules shall model the
time-dependent variations in occupancy,
illumination, receptacle loads, thermostat settings,
mechanical ventilation, HVAC equipment
availability, service hot water usage and any
process loads. The schedules shall be typical of
the proposed building type as determined by the
designer and approved by the jurisdiction.
Mechanical ventilationSame as proposedAs proposed, in accordance with Section C403.2.2.
Heating systemsFuel type: same as proposed designAs proposed
Equipment typea: as specified in Tables C407.5.1(2) and C407.5.1(3)As proposed
Efficiency: as specified in Tables C403.3.2(4) and C403.3.2(5)As proposed
Capacityb: sized proportionally to the capacities in the proposed design
based on sizing runs, and shall be established such that no smaller
number of unmet heating load hours and no larger heating capacity
safety factors are provided than in the proposed design.
As proposed
Cooling systemsFuel type: same as proposed designAs proposed
Equipment typec: as specified in Tables C407.5.1(2) and C407.5.1(3)As proposed
Efficiency: as specified in Tables C403.3.2(1), C403.3.2(2) and C403.3.2(3)As proposed
Capacityb: sized proportionally to the capacities in the proposed design
based on sizing runs, and shall be established such that no smaller
number of unmet cooling load hours and no larger cooling capacity
safety factors are provided than in the proposed design.
As proposed
Economizerd: same as proposed, in accordance with Section C403.5.As proposed
Service water heatingeFuel type: same as proposedAs proposed
Efficiency: as specified in Table C404.2For Group R, as proposed multiplied by SWHF.
For other than Group R, as proposed multiplied by
efficiency as provided by the manufacturer of the
DWHR unit.
Capacity: same as proposedAs proposed
Where no service water hot water system exists or is specified in the
proposed design, no service hot water heating shall be modeled.

SWHF = Service water heat recovery factor, DWHR = Drain water heat recovery.

  1. Where no heating system exists or has been specified, the heating system shall be modeled as fossil fuel. The system characteristics shall be identical in both the standard reference design and proposed design.
  2. The ratio between the capacities used in the annual simulations and the capacities determined by sizing runs shall be the same for both the standard reference design and proposed design.
  3. Where no cooling system exists or no cooling system has been specified, the cooling system shall be modeled as an air-cooled single-zone system, one unit per thermal zone. The system characteristics shall be identical in both the standard reference design and proposed design.
  4. If an economizer is required in accordance with Table C403.5(1) and where no economizer exists or is specified in the proposed design, then a supply-air economizer shall be provided in the standard reference design in accordance with Section C403.5.
  5. The SWHF shall be applied as follows:

    1. Where potable water from the DWHR unit supplies not less than one shower and not greater than two showers, of which the drain water from the same showers flows through the DWHR unit then SWHF = [1 (DWHR unit efficiency • 0.36)].
    2. Where potable water from the DWHR unit supplies not less than three showers and not greater than four showers, of which the drain water from the same showers flows through the DWHR unit then SWHF = [1 (DWHR unit efficiency • 0.33)].
    3. Where potable water from the DWHR unit supplies not less than five showers and not greater than six showers, of which the drain water from the same showers flows through the DWHR unit, then SWHF = [1 (DWHR unit efficiency • 0.26)].
    4. Where Items 1 through 3 are not met, SWHF = 1.0.

TABLE C407.5.1(2)

HVAC SYSTEMS MAP

CONDENSER COOLING
SOURCEa
HEATING SYSTEM
CLASSIFICATIONb
STANDARD REFERENCE DESIGN HVC SYSTEM TYPEc
Single-zone Residential
System
Single-zone Nonresidential
System
All Other
Water/groundElectric resistanceSystem 5System 5System 1
Heat pumpSystem 6System 6System 6
Fossil fuelSystem 7System 7System 2
Air/noneElectric resistanceSystem 8System 9System 3
Heat pumpSystem 8System 9System 3
Fossil fuelSystem 10System 11System 4
  1. Select “water/ground” where the proposed design system condenser is water or evaporatively cooled; select “air/none” where the condenser is air cooled. Closed-circuit dry coolers shall be considered to be air cooled. Systems utilizing district cooling shall be treated as if the condenser water type were “water.” Where mechanical cooling is not specified or the mechanical cooling system in the proposed design does not require heat rejection, the system shall be treated as if the condenser water type were “Air.” For proposed designs with ground-source or groundwater-source heat pumps, the standard reference design HVAC system shall be water-source heat pump (System 6).
  2. Select the path that corresponds to the proposed design heat source: electric resistance, heat pump (including air source and water source), or fuel fired. Systems utilizing district heating (steam or hot water) and systems without heating capability shall be treated as if the heating system type were “fossil fuel.” For systems with mixed fuel heating sources, the system or systems that use the secondary heating source type (the one with the smallest total installed output capacity for the spaces served by the system) shall be modeled identically in the standard reference design and the primary heating source type shall be used to determine standard reference design HVAC system type.
  3. Select the standard reference design HVAC system category: The system under “single-zone residential system” shall be selected where the HVAC system in the proposed design is a single-zone system and serves a Group R occupancy. The system under “single-zone nonresidential system” shall be selected where the HVAC system in the proposed design is a single-zone system and serves other than Group R occupancy. The system under “all other” shall be selected for all other cases.

TABLE C407.5.1(3)

SPECIFICATIONS FOR THE STANDARD REFERENCE DESIGN HVAC SYSTEM DESCRIPTIONS

SYSTEM NO.SYSTEM TYPEFAN CONTROLCOOLING TYPEHEATING TYPE
1Variable air volume with parallel fan-powered boxesaVAVdChilled watereElectric resistance
2Variable air volume with reheatbVAVdChilled watereHot water fossil fuel boilerf
3Packaged variable air volume with parallel fan-
powered boxesa
VAVdDirect expansioncElectric resistance
4Packaged variable air volume with reheatbVAVdDirect expansioncHot water fossil fuel boilerf
5Two-pipe fan coilConstant volumeiChilled watereElectric resistance
6Water-source heat pumpConstant volumeiDirect expansioncElectric heat pump and boilerg
7Four-pipe fan coilConstant volumeiChilled watereHot water fossil fuel boilerf
8Packaged terminal heat pumpConstant volumeiDirect expansioncElectric heat pumph
9Packaged rooftop heat pumpConstant volumeiDirect expansioncElectric heat pumph
10Packaged terminal air conditionerConstant volumeiDirect expansionHot water fossil fuel boilerf
11Packaged rooftop air conditionerConstant volumeiDirect expansionFossil fuel furnace

For SI: 1 foot = 304.8 mm, 1 cfm/ft2 = 0.4719 L/s, 1 Btu/h = 0.293/W, °C = [(°F) - 32]/1.8.

  1. VAV with parallel boxes: Fans in parallel VAV fan-powered boxes shall be sized for 50 percent of the peak design flow rate and shall be modeled with 0.35 W/cfm fan power. Minimum volume setpoints for fan-powered boxes shall be equal to the minimum rate for the space required for ventilation consistent with Section C403.6.1, Item 3. Supply air temperature setpoint shall be constant at the design condition.
  2. VAV with reheat: Minimum volume setpoints for VAV reheat boxes shall be 0.4 cfm/ft2 of floor area. Supply air temperature shall be reset based on zone demand from the design temperature difference to a 10°F temperature difference under minimum load conditions. Design airflow rates shall be sized for the reset supply air temperature, i.e., a 10°F temperature difference.
  3. Direct expansion: The fuel type for the cooling system shall match that of the cooling system in the proposed design.
  4. VAV: Where the proposed design system has a supply, return or relief fan motor 25 hp or larger, the corresponding fan in the VAV system of the standard reference design shall be modeled assuming a variable-speed drive. For smaller fans, a forward-curved centrifugal fan with inlet vanes shall be modeled. Where the proposed design’s system has a direct digital control system at the zone level, static pressure setpoint reset based on zone requirements in accordance with Section C403.8.5 shall be modeled.
  5. Chilled water: For systems using purchased chilled water, the chillers are not explicitly modeled and chilled water costs shall be based as determined in Sections C407.3 and C407.5.2. Otherwise, the standard reference design’s chiller plant shall be modeled with chillers having the number as indicated in Table C407.5.1(4) as a function of standard reference building chiller plant load and type as indicated in Table C407.5.1(5) as a function of individual chiller load. Where chiller fuel source is mixed, the system in the standard reference design shall have chillers with the same fuel types and with capacities having the same proportional capacity as the proposed design’s chillers for each fuel type. Chilled water supply temperature shall be modeled at 44°F design supply temperature and 56°F return temperature. Piping losses shall not be modeled in either building model. Chilled water supply water temperature shall be reset in accordance with Section C403.9.3. Pump system power for each pumping system shall be the same as the proposed design; where the proposed design has no chilled water pumps, the standard reference design pump power shall be 22 W/gpm (equal to a pump operating against a 75-foot head, 65-percent combined impeller and motor efficiency). The chilled water system shall be modeled as primary-only variable flow with flow maintained at the design rate through each chiller using a bypass. Chilled water pumps shall be modeled as riding the pump curve or with variable-speed drives where required in Section C403.9.3. The heat rejection device shall be an axial fan cooling tower with two-speed fans where required in Section C403.9. Condenser water design supply temperature shall be 85°F or 10°F approach to design wet-bulb temperature, whichever is lower, with a design temperature rise of 10°F. The tower shall be controlled to maintain a 70°F leaving water temperature where weather permits, floating up to leaving water temperature at design conditions. Pump system power for each pumping system shall be the same as the proposed design; where the proposed design has no condenser water pumps, the standard reference design pump power shall be 19 W/gpm (equal to a pump operating against a 60-foot head, 60-percent combined impeller and motor efficiency). Each chiller shall be modeled with separate condenser water and chilled water pumps interlocked to operate with the associated chiller.
  6. Fossil fuel boiler: For systems using purchased hot water or steam, the boilers are not explicitly modeled and hot water or steam costs shall be based on actual utility rates. Otherwise, the boiler plant shall use the same fuel as the proposed design and shall be natural draft. The standard reference design boiler plant shall be modeled with a single boiler where the standard reference design plant load is 600,000 Btu/h and less and with two equally sized boilers for plant capacities exceeding 600,000 Btu/h. Boilers shall be staged as required by the load. Hot water supply temperature shall be modeled at 180°F design supply temperature and 130°F return temperature. Piping losses shall not be modeled in either building model. Hot water supply water temperature shall be reset in accordance with Section C403.9.3. Pump system power for each pumping system shall be the same as the proposed design; where the proposed design has no hot water pumps, the standard reference design pump power shall be 19 W/gpm (equal to a pump operating against a 60-foot head, 60-percent combined impeller and motor efficiency). The hot water system shall be modeled as primary only with continuous variable flow. Hot water pumps shall be modeled as riding the pump curve or with variable speed drives where required by Section C403.9.3.
  7. Electric heat pump and boiler: Water-source heat pumps shall be connected to a common heat pump water loop controlled to maintain temperatures between 60°F and 90°F. Heat rejection from the loop shall be provided by an axial fan closed-circuit evaporative fluid cooler with two-speed fans where required in Section C403.8.5. Heat addition to the loop shall be provided by a boiler that uses the same fuel as the proposed design and shall be natural draft. Where no boilers exist in the proposed design, the standard reference building boilers shall be fossil fuel. The standard reference design boiler plant shall be modeled with a single boiler where the standard reference design plant load is 600,000 Btu/h or less and with two equally sized boilers for plant capacities exceeding 600,000 Btu/h. Boilers shall be staged as required by the load. Piping losses shall not be modeled in either building model. Pump system power shall be the same as the proposed design; where the proposed design has no pumps, the standard reference design pump power shall be 22 W/gpm, which is equal to a pump operating against a 75-foot head, with a 65-percent combined impeller and motor efficiency. Loop flow shall be variable with flow shutoff at each heat pump when its compressor cycles off as required by Section C403.9.3. Loop pumps shall be modeled as riding the pump curve or with variable speed drives where required by Section C403.9.3.
  8. Electric heat pump: Electric air-source heat pumps shall be modeled with electric auxiliary heat. The system shall be controlled with a multistage space thermostat and an outdoor air thermostat wired to energize auxiliary heat only on the last thermostat stage and when outdoor air temperature is less than 40°F.
  9. Constant volume: Fans shall be controlled in the same manner as in the proposed design; i.e., fan operation whenever the space is occupied or fan operation cycled on calls for heating and cooling. Where the fan is modeled as cycling and the fan energy is included in the energy efficiency rating of the equipment, fan energy shall not be modeled explicitly.

TABLE C407.5.1(4)

NUMBER OF CHILLERS

TOTAL CHILLER PLANT CAPACITYNUMBER OF CHILLERS
≤ 300 tons1
> 300 tons, < 600 tons2, sized equally
≥ 600 tons2 minimum, with chillers added so that all are sized equally and none is larger than 800 tons

For SI: 1 ton = 3517 W.

TABLE C407.5.1(5)

WATER CHILLER TYPES

INDIVIDUAL CHILLER PLANT CAPACITYELECTRIC CHILLER TYPEFOSSIL FUEL CHILLER TYPE
≤ 100 tonsReciprocatingSingle-effect absorption, direct fired
> 100 tons,< 300 tonsScrewDouble-effect absorption, direct fired
≥ 300 tonsCentrifugalDouble-effect absorption, direct fired

For SI: 1 ton = 3517 W.

The standard reference design and proposed design shall be analyzed using identical thermal blocks as specified in Section C407.5.2.1, C407.5.2.2 or C407.5.2.3.

Where HVAC zones are defined on HVAC design drawings, each HVAC zone shall be modeled as a separate thermal block.

Exception: Different HVAC zones shall be allowed to be combined to create a single thermal block or identical thermal blocks to which multipliers are applied, provided that:

  1. The space use classification is the same throughout the thermal block.
  2. All HVAC zones in the thermal block that are adjacent to glazed exterior walls face the same orientation or their orientations are within 45 degrees (0.79 rad) of each other.
  3. All of the zones are served by the same HVAC system or by the same kind of HVAC system.

Where HVAC zones have not yet been designed, thermal blocks shall be defined based on similar internal load densities, occupancy, lighting, thermal and temperature schedules, and in combination with the following guidelines:

  1. Separate thermal blocks shall be assumed for interior and perimeter spaces. Interior spaces shall be those located more than 15 feet (4572 mm) from an exterior wall. Perimeter spaces shall be those located closer than 15 feet (4572 mm) from an exterior wall.
  2. Separate thermal blocks shall be assumed for spaces adjacent to glazed exterior walls: a separate zone shall be provided for each orientation, except orientations that differ by not more than 45 degrees (0.79 rad) shall be permitted to be considered to be the same orientation. Each zone shall include floor area that is 15 feet (4572 mm) or less from a glazed perimeter wall, except that floor area within 15 feet (4572 mm) of glazed perimeter walls having more than one orientation shall be divided proportionately between zones.
  3. Separate thermal blocks shall be assumed for spaces having floors that are in contact with the ground or exposed to ambient conditions from zones that do not share these features.
  4. Separate thermal blocks shall be assumed for spaces having exterior ceiling or roof assemblies from zones that do not share these features.
Group R-2 occupancy spaces shall be modeled using one thermal block per space except that those facing the same orientations are permitted to be combined into one thermal block. Corner units and units with roof or floor loads shall only be combined with units sharing these features.

Calculation procedures used to comply with this section shall be software tools capable of calculating the annual energy consumption of all building elements that differ between the standard reference design and the proposed design and shall include the following capabilities.

  1. Building operation for a full calendar year (8,760 hours).
  2. Climate data for a full calendar year (8,760 hours) and shall reflect approved coincident hourly data for temperature, solar radiation, humidity and wind speed for the building location.
  3. Ten or more thermal zones.
  4. Thermal mass effects.
  5. Hourly variations in occupancy, illumination, receptacle loads, thermostat settings, mechanical ventilation, HVAC equipment availability, service hot water usage and any process loads.
  6. Part-load performance curves for mechanical equipment.
  7. Capacity and efficiency correction curves for mechanical heating and cooling equipment.
  8. Printed code official inspection checklist listing each of the proposed design component characteristics from Table C407.5.1(1) determined by the analysis to provide compliance, along with their respective performance ratings including, but not limited to, R-value, U-factor, SHGC, HSPF, AFUE, SEER, EF.
Performance analysis tools complying with the applicable subsections of Section C407 and tested according to ASHRAE Standard 140 shall be permitted to be approved. Tools are permitted to be approved based on meeting a specified threshold for a jurisdiction. The code official shall be permitted to approve tools for a specified application or limited scope.
Where calculations require input values not specified by Sections C402, C403, C404 and C405, those input values shall be taken from an approved source.

Where the simulation program does not model a design, material or device of the proposed design, an exceptional calculation method shall be used where approved by the code official. Where there are multiple designs, materials or devices that the simulation program does not model, each shall be calculated separately and exceptional savings determined for each. The total exceptional savings shall not constitute more than half of the difference between the baseline building performance and the proposed building performance. Applications for approval of an exceptional method shall include all of the following:

  1. Step-by-step documentation of the exceptional calculation method performed, detailed enough to reproduce the results.
  2. Copies of all spreadsheets used to perform the calculations.
  3. A sensitivity analysis of energy consumption where each of the input parameters is varied from half to double the value assumed.
  4. The calculations shall be performed on a time step basis consistent with the simulation program used.
  5. The performance rating calculated with and without the exceptional calculation method.
This section covers the provision of maintenance information and the commissioning of, and the functional testing requirements for, building systems.
The building operations and maintenance documents shall be provided to the owner and shall consist of manufacturers’ information, specifications and recommendations; programming procedures and data points; narratives; and other means of illustrating to the owner how the building, equipment and systems are intended to be installed, maintained and operated. Required regular maintenance actions for equipment and systems shall be clearly stated on a readily visible label. The label shall include the title or publication number for the operation and maintenance manual for that particular model and type of product.

Prior to the final mechanical and plumbing inspections, the registered design professional or approved agency shall provide evidence of mechanical systems commissioning and completion in accordance with the provisions of this section.

Construction document notes shall clearly indicate provisions for commissioning and completion requirements in accordance with this section and are permitted to refer to specifications for further requirements. Copies of all documentation shall be given to the owner or owner’s authorized agent and made available to the code official upon request in accordance with Sections C408.2.4 and C408.2.5.

Exceptions: The following systems are exempt:

  1. Mechanical systems and service water heater systems in buildings where the total mechanical equipment capacity is less than 480,000 Btu/h (140.7 kW) cooling capacity and 600,000 Btu/h (175.8 kW) combined service water-heating and space-heating capacity.
  2. Systems included in Section C403.5 that serve individual dwelling units and sleeping units.

A commissioning plan shall be developed by a registered design professional or approved agency and shall include the following items:

  1. A narrative description of the activities that will be accomplished during each phase of commissioning, including the personnel intended to accomplish each of the activities.
  2. A listing of the specific equipment, appliances or systems to be tested and a description of the tests to be performed.
  3. Functions to be tested including, but not limited to, calibrations and economizer controls.
  4. Conditions under which the test will be performed. Testing shall affirm winter and summer design conditions and full outside air conditions.
  5. Measurable criteria for performance.
HVAC systems shall be balanced in accordance with generally accepted engineering standards. Air and water flow rates shall be measured and adjusted to deliver final flow rates within the tolerances provided in the product specifications. Test and balance activities shall include air system and hydronic system balancing.

Each supply air outlet and zone terminal device shall be equipped with means for air balancing in accordance with the requirements of Chapter 6 of the International Mechanical Code. Discharge dampers used for air-system balancing are prohibited on constant-volume fans and variable volume fans with motors 10 hp (18.6 kW) and larger. Air systems shall be balanced in a manner to first minimize throttling losses then, for fans with system power of greater than 1 hp (0.746 kW), fan speed shall be adjusted to meet design flow conditions.

Exception: Fans with fan motors of 1 hp (0.74 kW) or less are not required to be provided with a means for air balancing.

Individual hydronic heating and cooling coils shall be equipped with means for balancing and measuring flow. Hydronic systems shall be proportionately balanced in a manner to first minimize throttling losses, then the pump impeller shall be trimmed or pump speed shall be adjusted to meet design flow conditions. Each hydronic system shall have either the capability to measure pressure across the pump, or test ports at each side of each pump.

Exception: The following equipment is not required to be equipped with a means for balancing or measuring flow

  1. Pumps with pump motors of 5 hp (3.7 kW) or less.
  2. Where throttling results in not greater than 5 percent of the nameplate horsepower draw above that required if the impeller were trimmed.
Functional performance testing specified in Sections C408.2.3.1 through C408.2.3.3 shall be conducted.

Equipment functional performance testing shall demonstrate the installation and operation of components, systems, and system-to-system interfacing relationships in accordance with approved plans and specifications such that operation, function, and maintenance serviceability for each of the commissioned systems is confirmed. Testing shall include all modes and sequence of operation, including under full-load, part-load and the following emergency conditions:

  1. All modes as described in the sequence of operation.
  2. Redundant or automatic back-up mode.
  3. Performance of alarms.
  4. Mode of operation upon a loss of power and restoration of power.

Exception: Unitary or packaged HVAC equipment listed in Tables C403.3.2(1) through C403.3.2(3) that do not require supply air economizers.

HVAC and service water-heating control systems shall be tested to document that control devices, components, equipment and systems are calibrated and adjusted and operate in accordance with approved plans and specifications. Sequences of operation shall be functionally tested to document they operate in accordance with approved plans and specifications.
Air economizers shall undergo a functional test to determine that they operate in accordance with manufacturer’s specifications.

A preliminary report of commissioning test procedures and results shall be completed and certified by the registered design professional or approved agency and provided to the building owner or owner’s authorized agent. The report shall be organized with mechanical and service hot water findings in separate sections to allow independent review. The report shall be identified as “Preliminary Commissioning Report,” shall include the completed Commissioning Compliance Checklist, Figure C408.2.4, and shall identify:

  1. Itemization of deficiencies found during testing required by this section that have not been corrected at the time of report preparation.
  2. Deferred tests that cannot be performed at the time of report preparation because of climatic conditions.
  3. Climatic conditions required for performance of the deferred tests.
  4. Results of functional performance tests.
  5. Functional performance test procedures used during the commissioning process, including measurable criteria for test acceptance.

FIGURE C408.2.4

COMMISSIONING COMPLIANCE CHECKLIST

Buildings, or portions thereof, shall not be considered as acceptable for a final inspection pursuant to Section C105.2.6 until the code official has received the Preliminary Commissioning Report from the building owner or owner’s authorized agent.
The code officialshall be permitted to require that a copy of the Preliminary Commissioning Report be made available for review by the code official.
The construction documents shall specify that the documents described in this section be provided to the building owner or owner’s authorized agent within 90 days of the date of receipt of the certificate of occupancy.
A written report describing the activities and measurements completed in accordance with Section C408.2.2.

A report of test procedures and results identified as “Final Commissioning Report” shall be delivered to the building owner or owner’s authorized agent. The report shall be organized with mechanical system and service hot water system findings in separate sections to allow independent review. The report shall include the following:

  1. Results of functional performance tests.
  2. Disposition of deficiencies found during testing, including details of corrective measures used or proposed.
  3. Functional performance test procedures used during the commissioning process including measurable criteria for test acceptance, provided herein for repeatability.

Exception: Deferred tests that cannot be performed at the time of report preparation due to climatic conditions.

Automatic lighting controls required by this code shall comply with this section.
Prior to passing final inspection, the registered design professional shall provide evidence that the lighting control systems have been tested to ensure that control hardware and software are calibrated, adjusted, programmed and in proper working condition in accordance with the construction documents and manufacturer’s instructions. Functional testing shall be in accordance with Sections C408.3.1.1 through C408.3.1.3 for the applicable control type.

Where occupant sensor controls are provided, the following procedures shall be performed:

  1. Certify that the occupant sensor has been located and aimed in accordance with manufacturer recommendations.
  2. For projects with seven or fewer occupant sensors, each sensor shall be tested.
  3. For projects with more than seven occupant sensors, testing shall be done for each unique combination of sensor type and space geometry. Where multiples of each unique combination of sensor type and space geometry are provided, not less than 10 percent and in no case fewer than one, of each combination shall be tested unless the code official or design professional requires a higher percentage to be tested. Where 30 percent or more of the tested controls fail, all remaining identical combinations shall be tested.

    For occupant sensor controls to be tested, verify the following:

    1. 3.1. Where occupant sensor controls include status indicators, verify correct operation.
    2. 3.2. The controlled lights turn off or down to the permitted level within the required time.
    3. 3.3. For auto-on occupant sensor controls, the lights turn on to the permitted level when an occupant enters the space.
    4. 3.4. For manual-on occupant sensor controls, the lights turn on only when manually activated.
    5. 3.5. The lights are not incorrectly turned on by movement in adjacent areas or by HVAC operation.

Where time-switch controls are provided, the following procedures shall be performed:

  1. Confirm that the time-switch control is programmed with accurate weekday, weekend and holiday schedules.
  2. Provide documentation to the owner of time-switch controls programming including weekday, weekend, holiday schedules, and set-up and preference program settings.
  3. Verify the correct time and date in the time switch.
  4. Verify that any battery back-up is installed and energized.
  5. Verify that the override time limit is set to not more than 2 hours.
  6. Simulate occupied condition. Verify and document the following:

    1. 6.1. All lights can be turned on and off by their respective area control switch.
    2. 6.2. The switch only operates lighting in the enclosed space in which the switch is located.
  7. Simulate unoccupied condition. Verify and document the following:

    1. 7.1. Nonexempt lighting turns off.
    2. 7.2. Manual override switch allows only the lights in the enclosed space where the override switch is located to turn on or remain on until the next scheduled shutoff occurs.
  8. Additional testing as specified by the registered design professional.

Where daylight responsive controls are provided, the following shall be verified:

  1. Control devices have been properly located, field calibrated and set for accurate setpoints and threshold light levels.
  2. Daylight controlled lighting loads adjust to light level setpoints in response to available daylight.
  3. The calibration adjustment equipment is located for ready access only by authorized personnel.
The construction documents shall specify that the documents described in this section be provided to the building owner or owner’s authorized agent within 90 days of the date of receipt of the certificate of occupancy.
Construction documents shall include the location and catalogue number of each piece of equipment.

An operating and maintenance manual shall be provided and include the following:

  1. Name and address of not less than one service agency for installed equipment.
  2. A narrative of how each system is intended to operate, including recommended setpoints.
  3. Submittal data indicating all selected options for each piece of lighting equipment and lighting controls.
  4. Operation and maintenance manuals for each piece of lighting equipment. Required routine maintenance actions, cleaning and recommended relamping shall be clearly identified.
  5. A schedule for inspecting and recalibrating all lighting controls.

A report of test results shall be provided and include the following:

  1. Results of functional performance tests.
  2. Disposition of deficiencies found during testing, including details of corrective measures used or proposed.
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