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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, excluding section 9.4.1.1(g), section 8.4.2 and section 8.4.3 of the standard.
  2. The requirements of Sections C402 through C405 and Section 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, C404, C405.2, C405.4, C405.5, C407 and C408. The building energy cost shall be equal to or less than 85 percent of the standard reference design building.
Commercial buildings and tenant spaces shall comply with Section C408 as applicable.
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 C403.2.14.
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 set point 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 meet 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 in framing cavities, where required, and for continuous insulation, where required, shall be not less than that specified in Table C402.1.3, based on the climate zone specified in Chapter 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. The thermal resistance or R-value of the insulating material installed continuously within or on the below-grade exterior walls of the building envelope required in accordance with Table C402.1.3 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. Opaque swinging doors shall comply with Table C402.1.4 and opaque nonswinging doors shall comply with Table C402.1.3.
OPAQUE THERMAL ENVELOPE INSULATION COMPONENT MINIMUM REQUIREMENTS, R-VALUE METHODa
CLIMATE ZONE 1 2 3 4 EXCEPT MARINE 5 AND MARINE 4 6 7 8
All other Group R All other Group R All other Group R All other Group R All other Group R All other Group R All other Group R All other Group R
Roofs
Insulation entirely
above roof deck
R-20ci R-25ci R-25ci R-25ci R-25ci R-25ci R-30ci R-30ci R-30ci R-30ci R-30ci R-30ci R-35ci R-35ci R-35ci R-35ci
Metal buildinga, b R-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 other R-38 R-38 R-38 R-38 R-38 R-38 R-38 R-38 R-38 R-49 R-49 R-49 R-49 R-49 R-49 R-49
Walls, above grade
Mass R-5.7cic R-5.7cic R-5.7cic R-7.6ci R-7.6ci R-9.5ci R-9.5ci R-11.4ci R-11.4ci R-13.3ci R-13.3ci R-15.2ci R-15.2ci R-15.2ci R-25ci R-25ci
Metal building R-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 framed R-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 walld NR NR NR NR NR NR R-7.5ci R-7.5ci R-7.5ci R-7.5ci R-7.5ci R-7.5ci R-10ci R-10ci R-10ci R-12.5ci
Floors
Masse NR NR R-6.3ci R-8.3ci R-10ci R-10ci R-10ci R-10.4ci R-10ci R-12.5ci R-12.5ci R-12.5ci R-15ci R-16.7ci R-15ci R-16.7ci
Joist/framing NR NR R-30 R-30 R-30 R-30 R-30 R-30 R-30 R-30 R-30 R-30f R-30f R-30f R-30f R-30f
Slab-on-grade floors
Unheated slabs NR NR NR NR NR NR R-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 slabsf R-7.5 for
12" below
R-7.5 for
12" below
R-7.5 for
12" below
R-7.5 for
12" below
R-10 for
24" below
R-10 for
24" below
R-15 for
24" below
R-15 for
24" below
R-15 for
36" below
R-15 for
36" below
R-15 for
36" below
R-20 for
48" below
R-20 for
24" below
R-20 for
48" below
R-20 for
48" below
R-20 for
48" below
Opaque doors
Nonswinging R-4.75 R-4.75 R-4.75 R-4.75 R-4.75 R-4.75 R-4.75 R-4.75 R-4.75 R-4.75 R-4.75 R-4.75 R-4.75 R-4.75 R-4.75 R-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 include floors weighing not less than:
    1. 35 pounds per square foot of floor surface area; or
    2. 25 pounds per square foot of floor surface area where the material weight is not more than 120 pounds per cubic foot.
  6. Steel floor joist systems shall be insulated to R-38.
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. The C-factor for the below-grade exterior walls of the building envelope, as required in accordance with Table C402.1.4, shall extend to a depth of 10 feet (3048 mm) below the outside finished ground level, or to the level of the lowest floor, whichever is less. Opaque swinging doors shall comply with Table C402.1.4 and opaque nonswinging doors shall comply with Table C402.1.3.
OPAQUE THERMAL ENVELOPE ASSEMBLY MAXIMUM REQUIREMENTS, U-FACTOR METHODa, b
CLIMATE ZONE 1 2 3 4
EXCEPT MARINE
5
AND MARINE 4
6 7 8
All other Group R All other Group R All other Group R All other Group R All other Group R All other Group R All other Group R All other Group R
Roofs
Insulation entirely
above roof deck
U-0.048 U-0.039 U-0.039 U-0.039 U-0.039 U-0.039 U-0.032 U-0.032 U-0.032 U-0.032 U-0.032 U-0.032 U-0.028 U-0.028 U-0.028 U-0.028
Metal buildings U-0.044 U-0.035 U-0.035 U-0.035 U-0.035 U-0.035 U-0.035 U-0.035 U-0.035 U-0.035 U-0.031 U-0.031 U-0.029 U-0.029 U-0.029 U-0.029
Attic and other U-0.027 U-0.027 U-0.027 U-0.027 U-0.027 U-0.027 U-0.027 U-0.027 U-0.027 U-0.021 U-0.021 U-0.021 U-0.021 U-0.021 U-0.021 U-0.021
Walls, above grade
Mass U-0.151 U-0.151 U-0.151 U-0.123 U-0.123 U-0.104 U-0.104 U-0.090 U-0.090 U-0.080 U-0.080 U-0.071 U-0.071 U-0.061 U-0.061 U-0.061
Metal building U-0.079 U-0.079 U-0.079 U-0.079 U-0.079 U-0.052 U-0.052 U-0.052 U-0.052 U-0.052 U-0.052 U-0.052 U-0.052 U-0.039 U-0.052 U-0.039
Metal framed U-0.077 U-0.077 U-0.077 U-0.064 U-0.064 U-0.064 U-0.064 U-0.064 U-0.064 U-0.064 U-0.064 U-0.057 U-0.064 U-0.052 U-0.045 U-0.045
Wood framed and
otherc
U-0.064 U-0.064 U-0.064 U-0.064 U-0.064 U-0.064 U-0.064 U-0.064 U-0.064 U-0.064 U-0.051 U-0.051 U-0.051 U-0.051 U-0.036 U-0.036
Walls, below grade
Below-grade wallc C-1.140e C-1.140e C-1.140e C-1.140e C-1.140e C-1.140e C-0.119 C-0.119 C-0.119 C-0.119 C-0.119 C-0.119 C-0.092 C-0.092 C-0.092 C-0.092
Floors
Massd U-0.322e U-0.322e U-0.107 U-0.087 U-0.076 U-0.076 U-0.076 U-0.074 U-0.074 U-0.064 U-0.064 U-0.057 U-0.055 U-0.051 U-0.055 U-0.051
Joist/framing U-0.066e U-0.066e U-0.033 U-0.033 U-0.033 U-0.033 U-0.033 U-0.033 U-0.033 U-0.033 U-0.033 U-0.033 U-0.033 U-0.033 U-0.033 U-0.033
Slab-on-grade floors
Unheated slabs F-0.73e F-0.73e F-0.73e F-0.73e F-0.73e F-0.73e F-0.54 F-0.54 F-0.54 F-0.54 F-0.54 F-0.52 F-0.40 F-0.40 F-0.40 F-0.40
Heated slabsf F-0.70 F-0.70 F-0.70 F-0.70 F-0.70 F-0.70 F-0.65 F-0.65 F-0.65 F-0.65 F-0.58 F-0.58 F-0.55 F-0.55 F-0.55 F-0.55
Opaque doors
Swinging door U-0.61 U-0.61 U-0.61 U-0.61 U-0.61 U-0.61 U-0.61 U-0.61 U-0.37 U-0.37 U-0.37 U-0.37 U-0.37 U-0.37 U-0.37 U-0.37
Garage door
<14% glazingg
U-0.31 U-0.31 U-0.31 U-0.31 U-0.31 U-0.31 U-0.31 U-0.31 U-0.31 U-0.31 U-0.31 U-0.31 U-0.31 U-0.31 U-0.31 U-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. Use of Opaque assembly U-factors, C-factors, and F-factors from ANSI/ASHRAE/IESNA 90.1 Appendix A shall be permitted, provided the construction, excluding the cladding system on walls, complies with the appropriate construction details from ANSI/ASHRAE/ISNEA 90.1 Appendix A.
  2. Opaque assembly U-factors based on designs tested in accordance with ASTM C1363 shall be permitted. 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 F-factor requirements for heated slabs.
  4. "Mass floors" shall include floors weighing not less than:
    1. 35 pounds per square foot of floor surface area; or
    2. 25 pounds per square foot of floor surface area where the material weight is not more than 120 pounds per cubic foot.
  5. These C-, F- and U-factors are based on assemblies that are not required to contain insulation.
  6. Evidence of compliance with the F-factors indicated in the table for heated slabs shall be demonstrated by the application of the unheated slab F-factors and R-values derived from ASHRAE 90.1 Appendix A.
  7. Garage doors having a single row of fenestration shall have an assembly U-factor less than or equal to 0.44, provided that the fenestration area is not less than 14 percent and not more than 25 percent of the total door area.
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.
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)
31/2 16 13 0.46 5.98
15 0.43 6.45
31/2 24 13 0.55 7.15
15 0.52 7.80
6 16 19 0.37 7.03
21 0.35 7.35
6 24 19 0.45 8.55
21 0.43 9.03
8 16 25 0.31 7.75
24 25 0.38 9.50
Building envelope values and fenestration areas determined in accordance with Equation 4-2 shall be permitted in lieu of 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.

(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 • Area.
UA Table = (U-factor from Table C402.1.4 or Table C402.4) • Area.
B = Sum of the (FL Dif) values for each distinct slab-ongrade perimeter condition of the building thermal envelope.
FL Dif = FL Proposed - FL Table.
FL Proposed = Proposed F-value • Perimeter length.
FL Table = (F-factor specified in Table C402.1.4) • Perimeter length.
C = Sum of the (CA Dif) values for each distinct belowgrade wall assembly type of the building thermal envelope.
CA Dif = CA Proposed - CA Table.
CA Proposed = Proposed C-value • Area.
CA Table = (Maximum allowable C-factor specified in Table C402.1.4) • 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 • UV) - (DA • 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 • US) - (EA • 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.
Where two or more layers of continuous insulation board are used in a construction assembly, the continuous insulation boards shall be installed in accordance with Section C303.2. Where the continuous insulation board manufacturer's instructions do not address installation of two or more layers, the edge joints between each layer of continuous insulation boards shall be staggered.
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. Skylight curbs shall be insulated to the level of roofs with insulation entirely above deck or R-5, whichever is less.
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. 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.
Insulation installed on a suspended ceiling with removable ceiling tiles shall not be considered part of the minimum thermal resistance of the roof insulation.
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.
"Mass walls" shall include walls:
  1. Weighing not less than 35 psf (170 kg/m2) of wall surface area.
  2. Weighing not less than 25 psf (120 kg/m2) of wall surface area where the material weight is not more than 120 pcf (1900 kg/m3).
  3. Having a heat capacity exceeding 7 Btu/ft2 • °F (144 kJ/m2 • K).
  4. Having 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.
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 insulation shall be placed on the outside of the foundation or on the inside of the foundation wall. The insulation shall extend downward from the top of the slab for a minimum distance as shown in the table or to the top of the footing, whichever is less, or downward to at least 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.
Upcodes Diagrams
Radiant heating system panels, and their associated components that are installed in interior or exterior assemblies shall be insulated with a minimum of R-3.5 (0.62 m2/K • W) 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 C402.2.5.
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.
MINIMUM ROOF REFLECTANCE AND EMITTANCE OPTIONSa
Three-year aged solar reflectanceb of 0.55 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-1 Standard.
  3. Aged thermal emittance tested in accordance with ASTM C1371 or ASTM E408 or CRRC-1 Standard.
  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-1 Standard.
Fenestration shall comply with Sections C402.4 through C402.4.4 and Table C402.4. Daylight responsive controls shall comply with this section and Section C405.2.3.1.
BUILDING ENVELOPE FENESTRATION MAXIMUM U-FACTOR AND SHGC REQUIREMENTS
CLIMATE ZONE 1 2 3 4 EXCEPT
MARINE
5 AND
MARINE 4
6 7 8
Vertical fenestration
U-factor
Fixed fenestration 0.50 0.50 0.46 0.38 0.38 0.36 0.29 0.29
Operable fenestration 0.65 0.65 0.60 0.45 0.45 0.43 0.37 0.37
Entrance doors 1.10 0.83 0.77 0.77 0.77 0.77 0.77 0.77
SHGC
Orientationa SEW N SEW N SEW N SEW N SEW N SEW N SEW N SEW N
PF < 0.2 0.25 0.33 0.25 0.33 0.25 0.33 0.40 0.53 0.40 0.53 0.40 0.53 0.45 NR 0.45 NR
0.2 ≤ PF < 0.5 0.30 0.37 0.30 0.37 0.30 0.37 0.48 0.58 0.48 0.58 0.48 0.58 NR NR NR NR
PF ≥ 0.5 0.40 0.40 0.40 0.40 0.40 0.40 0.64 0.64 0.64 0.64 0.64 0.64 NR NR NR NR
Skylights
U-factor 0.75 0.65 0.55 0.50 0.50 0.50 0.50 0.50
SHGC 0.35 0.35 0.35 0.40 0.40 0.40 NR NR
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 not be greater than 30 percent of the gross above-grade wall area. The skylight area shall not be 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 permitted to be vertical fenestration, provided 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. Exception: Fenestration that is outside the scope of NFRC 200 is not required to comply with Item 4.
Where daylight responsive controls complying with Section C405.2.3.1 are provided in daylight zones under skylights, the allowed skylight area shall not be greater than 6 percent of the gross roof area or that required for compliance with Section C402.4.2, Item 1, whichever is greater.
Skylights shall be provided in enclosed spaces 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 comply with 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 at least 0.40, or VTannual of not less than 0.26 as determined in accordance with Section C303.1.3.
  2. A minimum skylight effective aperture determined in accordance with Equation 4-4 of:
    1. Not less than 1 percent, using a skylight's VT rating; or
    2. Not less than 0.66 percent using a Tubular Daylighting Device's VTannual rating.

(Equation 4-4)
where:
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, or 1.0 for Tubular Daylighting Devices with VTannual ratings.
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 at least 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 according to 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 and/or tubular daylighting devices designed and installed to exclude direct sunlight entering the occupied space by the use of fixed or automated baffles, the geometry of skylight and light well, or the use of optical diffuser components.
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 doors shall comply with the applicable requirements for doors as specified in Tables C402.1.3 and C402.1.4 and be considered 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 E779 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. Joints and seals associated with penetrations shall be sealed in the same manner or taped or covered with moisture vapor-permeable wrapping material. Sealing materials shall be appropriate to the construction materials being sealed and 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.
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 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 a minimum density of 1.5 pcf (2.4 kg/m3) 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 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.
MAXIMUM AIR LEAKAGE RATE FOR FENESTRATION ASSEMBLIES
FENESTRATION
ASSEMBLY
MAXIMUM
RATE (CFM/FT2)
TEST
PROCEDURE
Windows 0.20 a AAMA/WDMA/CSA101/I.S.2/A440
or
NFRC 400
Sliding doors 0.20 a
Swinging doors 0.20 a
Skylights — with condensation
weepage openings
0.30
Skylights — all other 0.20 a
Curtain walls 0.06 NFRC 400
or
ASTM E283 at 1.57 psf
(75 Pa)
Storefront glazing 0.06
Power-operated sliding
doors and power-operated
folding doors, Commercial
glazed swinging
1.00
Revolving doors 1.00
Garage doors 0.40 ANSI/DASMA 105,
NFRC 400, or
ASTM E283 at
1.57 psf (75 Pa)
Rolling doors 1.00
High-speed doors 1.30
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 open combustion air ducts provide combustion air to open combustion space conditioning fuel-burning appliances, the appliances and combustion air openings shall be located outside of the building thermal envelope or enclosed in a room isolated from inside the thermal envelope. Such rooms shall be sealed and insulated in accordance with the envelope requirements of Table C402.1.3 or C402.1.4, where the walls, floors and ceilings shall meet the minimum of the below-grade wall R-value requirement. The door into the room shall be fully gasketed, and any water lines and ducts in the room insulated in accordance with Section C403. The combustion air duct shall be insulated, where it passes through conditioned space, to a minimum of R-8.
Exceptions:
  1. Direct vent appliances with both intake and exhaust pipes installed continuous to the outside.
  2. Fireplaces and stoves complying with Sections 901 through 905 of the Florida Building Code, Mechanical, and Section 2111.13 of the Florida Building Code, Building.
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 Florida Building Code, Building.
  2. Doors and door openings required to comply with UL 1784 by the Florida Building Code, Building.
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 C403.2.4.3.
Cargo doors and loading dock door openings shall be equipped with weatherseals that restrict infiltration and provide direct contact along the top and sides of vehicles 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.
Where vented dropped ceiling cavities occur over conditioned spaces, the ceiling shall be considered to be both the upper thermal envelope and pressure envelope of the building and shall contain a continuous air barrier between the conditioned space and the vented unconditioned space that is also sealed to the air barrier of the walls. See the definition of air barrier in Section C202.
Where unvented dropped ceiling cavities occur over conditioned spaces that do not have an air barrier between the conditioned and unconditioned space (such as T-bar ceilings), they shall be completely sealed from the exterior environment (at the roof plane) and adjacent spaces by a continuous air barrier that is also sealed to the air barrier of the walls. In that case, the roof assembly shall constitute both the upper thermal envelope and pressure envelope of the building.
Unconditioned spaces above separate tenancies shall contain dividing partitions between the tenancies to form a continuous air barrier that is sealed at the ceiling and roof to prevent airflow between them.
Building cavities designed to be air distribution system components shall be sealed according to the criteria for air ducts, plenums, etc., in Section C403.2.9.
Mechanical systems and equipment serving the building heating, cooling or ventilating needs shall comply with Section C403.2 and shall comply with Sections C403.3 and C403.4 based on the equipment and systems provided.
Walk-in coolers, walk-in freezers, refrigerated warehouse coolers and refrigerated warehouse freezers shall comply with Section C403.2.14.
Mechanical systems and equipment serving the building heating, cooling or ventilating needs shall comply with Sections C403.2.1 through C403.2.14.
Design loads associated with heating, ventilating and air conditioning of the building shall be determined in accordance with ANSI/ASHRAE/ACCA Standard 183 or ACCA Manual N 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. Design loads shall be attached to the code compliance form submitted to the building department when the building is permitted or, in the event the mechanical permit is obtained at a later time, the sizing calculation shall be submitted with the application for the mechanical permit.
Exception: Where mechanical systems are designed by a registered engineer, the engineer has the option of submitting a signed and sealed summary sheet to the building department in lieu of the complete sizing calculation(s). Such summary sheet shall include the following (by zone):
  1. Project name/owner
  2. Project address
  3. Area in square feet
  4. Sizing method used
  5. Outdoor dry bulb use
  6. Indoor dry bulb
  7. Outdoor wet bulb used
  8. Grains water (difference)
  9. Total sensible gain
  10. Total latent gain
  11. Relative humidity
  12. Total cooling required with outside air
  13. Total heating required with outside air
The output capacity of heating and cooling equipment shall be not greater than the loads calculated in accordance with Section C403.2.1. 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 have the capability to sequence the operation of each unit based on load.
Equipment shall meet the minimum efficiency requirements of Tables C403.2.3(1), C403.2.3(2), C403.2.3(3), C403.2.3(4), C403.2.3(5), C403.2.3(6), C403.2.3(7), C403.2.3(8) and C403.2.3(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 C403.2.3(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.

MINIMUM EFFICIENCY REQUIREMENTS:
ELECTRICALLY OPERATED UNITARY AIR CONDITIONERS AND CONDENSING UNITS
SIZE CATEGORY
HEATING SECTION TYPE
SUBCATEGORY OR RATING CONDITION
MINIMUM EFFICIENCY
TEST PROCEDUREa
Air conditioners, air cooled
< 45,000 Btu/hb
All
Split System, single phaseb
14.0 SEER
before 1/1/2023
14.3 SEER2
after 1/1/2023
AHRI 210/240 — 2017 before 1/1/2023
AHRI 210/240 — 2023 after 1/1/2023
≥ 45,000 Btu/hb
and

< 65,000 Btu/hb

< 65,000 Btu/hb
14.0 SEER
before 1/1/2023
13.8 SEER2
after 1/1/2023
Single Package, single phaseb
14.0 SEER
Through-the-wall
(air cooled)
≤30,000 Btu/hb
All
Split system, three phase and US applications single phaseb
12.0 SEER
Single Package, three phase and US applications single phaseb
12.0 SEER
Small-duct high-velocity (air cooled)
< 65,000 Btu/hb
All
Split system, single phaseb
12.0 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
12.9 IEER
AHRI 340/360
All other Split System and
Single Package
11.0 EER
12.7 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 other Split 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 other Split System and
Single Package
9.8 EER
11.4 IEER
≥ 760,000 Btu/h Electric Resistance
(or None)
Split System and
Single Package
9.7 EER
11.2 IEER
All other Split System and
Single Package
9.5 EER
11.0 IEER
Air conditioners, water cooled < 65,000 Btu/hb All Split 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 other Split System and
Single Package
11.9 EER
13.7 IEER
≥ 135,000 Btu/h
and
< 240,000 Btu/h




≥ 240,000 Btu/h
and
< 760,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
12.5 EER
13.9 IEER
All other Split System and
Single Package

Split System and
Single Package
12.3 EER
13.7 IEER

12.4 EER
13.6 IEER
Electric Resistance
(or None)
All other Split System and
Single Package
12.2 EER
13.4 IEER
≥ 760,000 Btu/h Electric Resistance
(or None)
Split System and
Single Package
12.2 EER
13.5 IEER
All other Split System and
Single Package
12.0 EER
13.3 IEER
Air conditioners,
evaporatively cooled
< 65,000 Btu/hb All Split 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 other Split System and
Single Package
11.9 EER
12.1 IEER
≥ 135,000 Btu/h
and
< 240,000 Btu/h




≥ 240,000 Btu/h
and
< 760,000 Btu/h
Electric Resistance
(or None)
Split System and
Single Package
12.0 EER
12.2 IEER
All other Split System and
Single Package

Split System
and
Single Package
11.8 EER
12.0 IEER

11.9 EER
12.1 IEER
Electric Resistance
(or None)
All other Split System and
Single Package
11.7 EER
11.9 IEER
≥ 760,000 Btu/h Electric Resistance
(or None)
Split System and
Single Package
11.7 EER
11.9 IEER
All other Split System and
Single Package
11.5 EER
11.7 IEER
Condensing units, air cooled ≥ 135,000 Btu/h     10.5 EER
11.8 IEER
AHRI 365
Condensing units, water cooled ≥ 135,000 Btu/h     13.5 EER
14.0 IEER
Condensing units, evaporatively cooled ≥ 135,000 Btu/h     13.5 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 standards, which include test procedure, including the reference year version of the test procedure.
  2. Single-phase, US air-cooled air conditioners less than 65,000 Btu/h are regulated as consumer products by the US Department of Energy Code of Federal Regulations DOE 10 CFR 430. SEER and SEER2 values for single-phase products are set by the US Department of Energy.
MINIMUM EFFICIENCY REQUIREMENTS: ELECTRICALLY OPERATED UNITARY AND APPLIED HEAT PUMPS
EQUIPMENT TYPE SIZE CATEGORY HEATING
SECTION TYPE
SUBCATEGORY OR
RATING CONDITION
MINIMUM TEST PROCEDUREa
Air cooled (cooling mode) < 65,000 Btu/hb All Split System 14.0 SEER AHRI 210/240
Single Package 14.0 SEER
Through-the-wall, air cooled ≤ 30,000 Btu/hb All Split System 12.0 SEER
Single Package 12.0 SEER
Single-duct high-velocity air cooled < 65,000 Btu/hb All Split System 12.0 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 other Split 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 other Split System and
Single Package
10.4 EER
11.4 IEER
≥ 240,000 Btu/h Electric Resistance
(or None)
Split System and
Single Package
9.5 EER
10.6 IEER
All other Split System and
Single Package
9.3 EER
9.4 IEER
Water to Air: Water Loop
(cooling mode)
< 17,000 Btu/h All 86°F entering water 12.2 EER ISO 13256-1
≥ 17,000 Btu/h and
< 65,000 Btu/h
All 86°F entering water 13.0 EER
≥ 65,000 Btu/h and
< 135,000 Btu/h
All 86°F entering water 13.0 EER
Water to Air: Ground Water
(cooling mode)
< 135,000 Btu/h All 59°F entering water 18.0 EER ISO 13256-1
Brine to Air: Ground Loop
(cooling mode)
< 135,000 Btu/h All 77°F entering water 14.1 EER ISO 13256-1
Water to Water: Water Loop
(cooling mode)
< 135,000 Btu/h All 86°F entering water 10.6 EER ISO 13256-2
Water to Water: Ground Water
(cooling mode)
< 135,000 Btu/h All 59°F entering water 16.3 EER
Brine to Water: Ground Loop
(cooling mode)
< 135,000 Btu/h All 77°F entering fluid 12.1 EER
Air cooled (heating mode) < 65,000 Btu/hb Split System 8.2 HSPF AHRI 210/240
Single Package 8.0 HSPF
Through-the-wall,
(air cooled, heating mode)
≤ 30,000 Btu/hb (cooling capacity) Split System 7.4 HSPF
Single Package 7.4 HSPF
Small-duct high velocity
(air cooled, heating mode)
< 65,000 Btu/hb Split System 7.2 HSPF
Air cooled (heating mode) ≥ 65,000 Btu/h and
< 135,000 Btu/h
(cooling capacity)
47°F db/43°F wb 3.3 COP AHRI 340/360
17°Fdb/15°F wb 2.25 COP
≥ 135,000 Btu/h
(cooling capacity)
47°F db/43°F wb 3.2 COP
17°Fdb/15°F wb 2.05 COP
Water to Air: Water Loop
(heating mode)
< 135,000 Btu/h
(cooling capacity)
68°F entering water 4.3 COP ISO 13256-1
Water to Air: Ground Water
(heating mode)
< 135,000 Btu/h
(cooling capacity)
50°F entering water 3.7 COP
Brine to Air: Ground Loop
(heating mode)
< 135,000 Btu/h
(cooling capacity)
32°F entering fluid 3.2 COP
Water to Water: Water Loop
(heating mode)
< 135,000 Btu/h
(cooling capacity)
68°F entering water 3.7 COP ISO 13256-2
Water to Water: Ground Water
(heating mode)
< 135,000 Btu/h
(cooling capacity)
50°F entering water 3.1 COP
Brine to Water: Ground Loop
(heating mode)
< 135,000 Btu/h
(cooling capacity)
32°F entering fluid 2.5 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 air conditioners less than 65,000 Btu/h are regulated by NAECA. SEER values are those set by NAECA.
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 TYPE SIZE CATEGORY (INPUT) SUBCATEGORY OR
RATING CONDITION
MINIMUM EFFICIENCY TEST
PROCEDUREa
PTAC (cooling mode)
new construction
All Capacities 95°F db outdoor air 14.0 — (0.300 × Cap/1000) EER AHRI 310/380
PTAC (cooling mode) All Capacities 95°F db outdoor air 10.9 - (0.213 × Cap/1000) EER
PTHP (cooling mode)
new construction
All Capacities 95°F db outdoor air 14.0 - (0.300 × Cap/1000) EER
PTHP (cooling mode) All Capacities 95°F db outdoor air 10.8 - (0.213 × Cap/1000) EER
PTHP (heating mode)
new construction
All Capacities 3.7 - (0.052 × Cap/1000) COP
PTHP (heating mode) All Capacities 2.9 - (0.026 × Cap/1000) COP
SPVAC (cooling mode) < 65,000 Btu/h 95°F db/ 75°F wb outdoor air 11.0 EER AHRI 390
≥ 65,000 Btu/h and
< 135,000 Btu/h
95°F db/ 75°F wb outdoor air 10.0 EER
≥ 135,000 Btu/h and
< 240,000 Btu/h
95°F db/ 75°F wb outdoor air 10.0 EER
SPVHP (cooling mode) < 65,000 Btu/h 95°F db/ 75°F wb outdoor air 11.0 EER
≥ 65,000 Btu/h and
< 135,000 Btu/h
95°F db/ 75°F wb outdoor air 10.0 EER
≥ 135,000 Btu/h and
< 240,000 Btu/h
95°F db/ 75°F wb outdoor air 10.0 EER
SPVHP (heating mode) < 65,000 Btu/h 47°F db/ 43°F wb outdoor air 3.3 COP AHRI 390
≥ 65,000 Btu/h and
< 135,000 Btu/h
47°F db/ 43°F wb outdoor air 3.0 COP
≥ 135,000 Btu/h and
< 240,000 Btu/h
47°F db/ 75°F wb outdoor air 3.0 COP
Room air conditioners,
with louvered sides
< 6,000 Btu/h 11.0 CEER ANSI/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/h   9.0 CEER
Room air conditioners,
without louvered sides
< 6,000 Btu/h 10.0 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/h 9.8 CEER ANSI/AHAM RAC-1
≥ 20,000 Btu/h 9.3 CEER
Room air-conditioner
heat pumps without louvered sides
< 14,000 Btu/h 9.3 CEER
≥ 14,000 Btu/h 8.7 CEER
Room air conditioner casement only All capacities 9.5 CEER ANSI/AHAM RAC-1
Room air conditioner casement-slider All capacities 10.4 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.
WARM AIR FURNACES AND COMBINATION WARM AIR FURNACES/AIR-CONDITIONING UNITS, WARM-AIR DUCT FURNACES AND UNIT HEATERS, MINIMUM EFFICIENCY REQUIREMENTS
EQUIPMENT TYPE SIZE CATEGORY
(INPUT)
SUBCATEGORY OR
RATING CONDITION
MINIMUM TEST PROCEDUREa
Warm air furnaces, gas-fired
Non-weatherized
< 225,000 Btu/h 80% AFUE or 80%Et c
81% AFUE
DOE 10 CFR, Part 430 or
Section 2.39, Thermal Efficiency of ANSI Z 21.47
Weatherized gas furnace ≥ 225,000 Btu/h Maximum capacityc 80%Et f Section 2.39, Thermal
Efficiency of ANSI Z21.47
Warm air furnaces, oil-fired
Non-weatherized
< 225,000 Btu/h
83% AFUE or 80%Et c 78% AFUE
DOE 10 CFR, Part 430 or
Section 42, Combustion, of UL 727
Weatherized oil-fired furnace ≥ 225,000 Btu/h Maximum capacityb 81%Etg Section 42, Combustion, of UL 727
Warm air duct furnaces, gas-fired All capacities Maximum capacityb 80%Ec Section 2.10,
Efficiency of ANSI Z83.8
Warm air unit heaters, gas-fired All capacities Maximum capacityb 80%Ec Section 2.10,
Efficiency of ANSI Z83.8
Warm air unit heaters, oil-fired All capacities Maximum capacityb 80%Ec Section 40, Combustion, of UL 731
Mobile home furnace, gas-fired < 225,000 Btu/h 80% AFUE DOE 10 CFR, Part 430
Mobile home furnace, oil-fired < 225,000 Btu/h 75% AFUE DOE 10 CFR, Part 430
For SI: 1 British thermal unit per hour = 0.2931 W.
  1. Chapter 6, Referenced Standards, 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.
MINIMUM EFFICIENCY REQUIREMENTS: GAS- AND OIL-FIRED BOILERS
EQUIPMENT TYPEa SUBCATEGORY OR
RATING CONDITION
SIZE CATEGORY (INPUT) MINIMUM EFFICIENCYd, e TEST PROCEDURE
Boilers, hot water Gas-fired < 300,000 Btu/hf, g 84% AFUE 10 CFR Part 430
≥ 300,000 Btu/h and
≤ 2,500,000 Btu/hb
80% Et 10 CFR Part 431
> 2,500,000 Btu/ha 82% Ec
Oil-firedc < 300,000 Btu/hg 86% AFUE 10 CFR Part 430
≥ 300,000 Btu/h and
≤ 2,500,000 Btu/hb
82% Et 10 CFR Part 431
> 2,500,000 Btu/ha 84% Ec
Boilers, steam Gas-fired < 300,000 Btu/hf 82% AFUE 10 CFR Part 430
Gas-fired—all, except
natural draft
≥ 300,000 Btu/h and
≤ 2,500,000 Btu/hb
79% Et 10 CFR Part 431
> 2,500,000 Btu/ha 79% Et
Gas-fired—natural draft ≥ 300,000 Btu/h and
≤ 2,500,000 Btu/hb
77%
Et 79% Et effective
March 2, 2022
> 2,500,000 Btu/ha 77%
Et 79% Et effective
March 2, 2022
Oil-firedc < 300,000 Btu/h 85% AFUE 10 CFR Part 430
≥ 300,000 Btu/h and
≤ 2,500,000 Btu/hb
81% Et 10 CFR Part 431
> 2,500,000 Btu/ha 81% 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.
MINIMUM EFFICIENCY REQUIREMENTS: CONDENSING UNITS, ELECTRICALLY OPERATED
EQUIPMENT TYPE SIZE CATEGORY MINIMUM EFFICIENCYb TEST PROCEDUREa
Condensing units, air cooled ≥ 135,000 Btu/h 10.1 EER
11.2 IPLV
AHRI 365
Condensing units, water or evaporatively cooled ≥ 135,000 Btu/h 13.1 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.
WATER CHILLING PACKAGES — EFFICIENCY REQUIREMENTSa, b, d
EQUIPMENT
TYPE
SIZE
CATEGORY
UNITS BEFORE 1/1/2015 AS OF 1/1/2015 TEST
PROCEDUREc
Path A Path B Path A Path B
Air-cooled chillers < 150 tons EER
(Btu/W)
≥ 9.562 FL NAc ≥ 10.100 FL ≥ 9.700 FL AHRI 550/590
≥ 12.500 IPLV ≥ 13.700 IPLV ≥ 15,800 IPLV
≥ 150 tons ≥ 9.562 FL NAc ≥ 10.100 FL ≥ 9.700 FL
≥ 12.500 IPLV ≥ 14.000 IPLV ≥ 16.100 IPLV
Air cooled
without condenser,
electrically operated
All capacities EER
(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 tons kW/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 tons kW/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 capacities COP ≥ 0.600 FL NAc ≥ 0.600 FL NAc AHRI 560
Water cooled
absorption, single
effect
All capacities COP ≥ 0.700 FL NAc ≥ 0.700 FL NAc
Absorption, double
effect, indirect fired
All capacities COP ≥ 1.000 FL NAc ≥ 1.000 FL NAc
≥ 1.050 IPLV ≥ 1.050 IPLV
Absorption double
effect direct fired
All capacities COP ≥ 1.000 FL NAc ≥ 1.000 FL NAc
≥ 1.000 IPLV ≥ 1.050 IPLV
  1. The requirements for centrifugal chiller shall be adjusted for nonstandard rating conditions in accordance with Section C403.2.3.1 and are only applicable for the range of conditions listed in Section C403.2.3.1. 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.
MINIMUM EFFICIENCY REQUIREMENTS: HEAT REJECTION EQUIPMENT
EQUIPMENT TYPEa TOTAL SYSTEM
HEAT REJECTION
CAPACITY AT RATED
CONDITIONS
SUBCATEGORY OR
RATING CONDITIONi
PERFORMANCE
REQUIREDb, c, d, g, h
TEST PROCEDUREe, f
Propeller or axial fan
open-circuit cooling
towers
All 95°F entering water 8
5°F leaving water
75°F entering wb
≥ 40.2 gpm/hp CTI ATC-105 and
CTI STD-201
Centrifugal fan
open-circuit cooling
towers
All 95°F entering water
85°F leaving water
75°F entering wb
≥ 20.0 gpm/hp CTI ATC-105 and
CTI STD-201
Propeller or axial fan
closed-circuit cooling
towers
All 102°F entering water
90°F leaving water
75°F entering wb
≥ 16.1 gpm/hp CTI ATC-105S and
CTI STD-201
Centrifugal fan closed-
circuit cooling towers
All 102°F entering water
90°F leaving water
75°F entering wb
≥ 7.0 gpm/hp CTI ATC-105S and
CTI STD-201
Propeller or axial fan
evaporative condensers
All Ammonia Test Fluid
140°F entering gas temperature
96.3°F condensing temperature
75°F entering wb
≥ 134,000 Btu/h•hp CTI ATC-106
Centrifugal fan
evaporative condensers
All Ammonia Test Fluid
140°F entering gas temperature
96.3°F condensing temperature
75°F entering wb
≥110,000 Btu/h•hp CTI ATC-106
Propeller or axial fan
evaporative condensers
All R-507A Test Fluid
165°F entering gas temperature
105°F condensing temperature
75°F entering wb
≥ 157,000 Btu/h•hp CTI ATC-106
Centrifugal fan
evaporative condensers
All R-507A Test Fluid
165°F entering gas temperature
105°F condensing temperature
75°F entering wb
≥ 135,000 Btu/h•hp CTI ATC-106
Air-cooled condensers All 125°F Condensing Temperature
190°F Entering Gas Temperature
15°F subcooling
95°F entering db
≥ 176,000 Btu/h•hp AHRI 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 listed in Table 403.2.3(8) 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 listed in Table 403.2.3(8) 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 and/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.
MINIMUM EFFICIENCY AIR CONDITIONERS AND CONDENSING UNITS SERVING COMPUTER ROOMS
Type Net Sensible Cooling
Capacitya
Standard Model Minimum Net Sensible COPb (NSCOP) Test Procedure
Return Air Dry-Bulb Temperature /
Dew-Point Temperature
Class 1 Class 2 Class 3
Air cooled < 65,000 Btu/h Downflow unit   2.30   AHRI 1360
Upflow unit—ducted   2.10  
Upflow unit—nonducted 2.09    
Horizontal-flow unit     2.45
≥ 65,000 and < 240,000 Btu/h Downflow unit   2.20  
Upflow unit—ducted   2.05  
Upflow unit—nonducted 1.99    
Horizontal-flow unit     2.35
≥ 240,000 Btu/h Downflow unit   2.00  
Upflow unit—ducted   1.85  
Upflow unit—nonducted 1.79    
Horizontal-flow unit     2.15
Water cooled < 65,000 Btu/h Downflow unit   2.50   AHRI 1360
Upflow unit—ducted   2.30  
Upflow unit—nonducted 2.25    
Horizontal-flow unit     2.70
≥ 65,000 and < 240,000 Btu/h Downflow unit   2.40  
Upflow unit—ducted   2.20  
Upflow unit—nonducted 2.15    
Horizontal-flow unit     2.60
≥ 240,000 Btu/h Downflow unit   2.25  
Upflow unit—ducted   2.10  
Upflow unit—nonducted 2.05    
Horizontal-flow unit 2.45    
Water cooled with fluid economizer < 65,000 Btu/h Downflow unit   2.45   AHRI 1360
Upflow unit—ducted   2.25  
Upflow unit—nonducted 2.20    
Horizontal-flow unit     2.60
≥ 65,000 and < 240,000 Btu/h Downflow unit   2.35  
Upflow unit—ducted   2.15  
Upflow unit—nonducted 2.10    
Horizontal-flow unit     2.55
≥ 240,000 Btu/h Downflow unit   2.20  
Upflow unit—ducted   2.05  
Upflow unit—nonducted 2.00    
Horizontal-flow unit     2.40
Glycol cooled < 65,000 Btu/h Downflow unit   2.30   AHRI 1360
Upflow unit—ducted   2.10  
Upflow unit—nonducted 2.00    
Horizontal-flow unit     2.40
≤ 65,000 and < 240,000 Btu/h Downflow unit   2.05  
Upflow unit—ducted   1.85  
Upflow unit—nonducted 1.85    
Horizontal-flow unit     2.15
≥ 240,000 Btu/h Downflow unit   1.95  
Upflow unit—ducted   1.80  
Upflow unit—nonducted 1.75    
Horizontal-flow unit     2.10
Glycol cooled
with fluid economizer
< 65,000 Btu/h Downflow unit   2.25   AHRI 1360
Upflow unit—ducted   2.10  
Upflow unit—nonducted 2.00    
Horizontal-flow unit     2.35
≥ 65,000 and < 240,000 Btu/h Downflow unit   1.95  
Upflow unit—ducted   1.80  
Upflow unit—nonducted 1.75    
Horizontal-flow unit     2.10
≥ 240,000 Btu/h Downflow unit   1.90  
Upflow unit—ducted   1.80  
Upflow unit—nonducted 1.70    
Horizontal-flow unit     2.10
For SI: 1 British thermal unit per hour = 0.2931 W, °C = [(°F) — 32]/1.8
  1. Net Sensible Cooling Capacity. The rate, expressed in Btu/h and/or kW, at which the equipment removes sensible heat from the air passing through it under specified conditions of operation, including the fan energy dissipated into the conditioned space.
  2. Net Sensible Coefficient of Performance (NSCOP). A ratio of the Net Sensible Cooling Capacity in kilowatts to the total power input in kilowatts (excluding reheaters and humidifiers) at any given set of Rating Conditions defined in AHRI Standard 1360.
HEAT TRANSFER EQUIPMENT
EQUIPMENT TYPE SUBCATEGORY MINIMUM EFFICIENCY TEST PROCEDUREa
Liquid-to-liquid heat exchangers Plate type NR AHRI 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 TYPE SIZE CATEGORY HEATING TYPEa MINIMUM EFFICIENCY TEST PROCEDUREb
VRF Multi-split
Air Conditioners
(Air-cooled)
< 65,000 Btu/h All 13.0 SEER AHRI 1230
(omit Sections 5.1.2
and 6.6)
≥ 65,000 Btu/h and
< 135,000 Btu/h
Electric resistance (or none) 11.2 EER
All other 11.0 EER
≥ 135,000 Btu/h and
< 240,000 Btu/h
Electric resistance (or none) 11.0 EER
All other 10.8 EER
≥ 240,000 Btu/h and
< 760,000 Btu/h
Electric resistance (or none) 10.0 EER
All other 9.8 EER
VRF Multi-split
Heat Pumps
(Air-cooled)
< 65,000 Btu/h All 13.0 SEER
7.7 HSPF
≥ 65,000 Btu/h and
< 135,000 Btu/h
Electric resistance (or none) 11.0 EER
3.3 COP
All other 10.8 EER
3.3 COP
≥ 135,000 Btu/h and
< 240,000 Btu/h
Electric resistance (or none) 10.6 EER
3.2 COP
All other 10.4 EER
3.2 COP
≥ 240,000 Btu/h and
< 760,000 Btu/h
Electric resistance (or none) 9.5 EER
3.2 COP
All other 9.3 EER
3.2 COP
VRF Multi-split
Air Conditioners
(Water-source)
< 17,000 Btu/h Without heat recovery 12.0 EER
4.3 COP
With heat recovery 11.8 EER
4.3 COP
≥ 17,000 Btu/h and
< 65,000 Btu/h
All 12.0 EER
4.3 COP
≥ 65,000 Btu/h and
< 135,000 Btu/h
All 12.0 EER
4.3 COP
≥ 135,000 Btu/h and
< 760,000 Btu/h
Without heat recovery 10.0 EER
4.0 COP
With heat recovery 9.8 EER
4.0 COP
For SI: 1 British thermal unit per hour = 0.2931 W, °C = [(°F) — 32]/1.8
  1. VRAF Multi-split Heat Pumps (air-cooled) with heat recovery fall under the category of "All Other Types of Heating" unless they also have electric resistance heating, in which case it falls under the category for "No Heating or Electric Resistance Heating."
  2. Chapter 6, Referenced Standards, contains a complete specification of the referenced test procedure, including the reference 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 × B
FL = Full-load kW/ton value as specified in Table C403.2.3(7).
FLadj = Maximum full-load kW/ton rating, adjusted for nonstandard conditions.
IPLV = Value as specified in Table C403.2.3(7).
PLVadj = Maximum NPLV rating, adjusted for non-standard 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 = LvgCondLvgEvap
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 C403.2.3(7) when tested or certified with water at standard rating conditions, in accordance with the referenced test procedure.
Each heating and cooling system shall be provided with thermostatic controls as specified in Section C403.2.4.1, C403.2.4.1.3, C403.2.4.2, C403.2.4.3, C403.2.12.5, C403.3.1, C403.4, or C403.4.4.
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, at least 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:
  1. The perimeter system includes at least 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); and
  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 capable of providing a temperature range or deadband of at least 5°F (2.8°C) within which the supply of heating and cooling energy to the zone is capable of being 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 provided with the capability to prevent the heating set point from exceeding the cooling set point and to maintain a deadband in accordance with Section C403.2.4.1.2.
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 readily accessible manual shutoff switch.
Thermostatic setback controls shall have the capability 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 at least 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 capable of being adjusted 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.
Individual heating and cooling systems with setback controls and direct digital control shall have optimum start controls. The control algorithm shall, as a minimum, be a function of the difference between space temperature and occupied set point, the outdoor temperature, and the amount of time prior to scheduled occupancy. Mass radiant floor slab systems shall incorporate floor temperature into the optimum start algorithm.
Where humidification, dehumidification or both is provided, the following shall be met:
  1. At least one humidity control device shall be provided for each humidity control system.
  2. Controls shall be provided capable of preventing simultaneous operation of humidification and dehumidification equipment.
    Exceptions:
    1. Zones served by desiccant systems used with direct evaporative cooling in series.
    2. Systems serving zones where specific humidity levels are required, such as computer rooms, museums and hospitals, as approved by the building official.
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 Florida Building Code, Mechanical 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: Gravity (nonmotorized) dampers shall be permitted to be used 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).
Gravity (nonmotorized) 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.
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 C403.2.4.2.2. 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.
Snow- and ice-melting systems shall include automatic controls capable of shutting off the system when the pavement temperature is above 50°F (10°C) and no precipitation is falling and an automatic or manual control that will allow shutoff 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.
Air-cooled unitary direct-expansion units listed in Tables C403.2.3(1) through C403.2.3(3) and variable refrigerant flow (VRF) units that are equipped with an economizer in accordance with Section C403.3 shall include a fault detection and diagnostics (FDD) 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 capable of providing 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 capable of reporting faults to a fault management application accessible by day-to-day operating or service personnel, or annunciated locally on zone thermostats.
  7. The FDD system shall be capable of detecting 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.
In Group R-1 buildings containing over 50 guest rooms, each guest room shall be provided with controls complying with the provisions of Sections C403.2.4.8.1 and C403.2.4.8.2. 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 guest room. The controls shall also be capable of and configured to automatically raise the cooling setpoint to not lower than 80°F (27°C) and lower the heating set point to not higher than 60°F (16°C) when the guest room is unrented or has been continuously unoccupied for over 16 hours or a networked guest room control system indicates that the guest room is unrented and the guest room is unoccupied for more than 30 minutes. A networked guest room control system that is capable of returning the thermostat set-points to default occupied set-points 60 minutes prior to the time a guest room 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 guest room or isolation devices shall be provided to each guest room that are capable of automatically shutting off the supply of outdoor air to and exhaust air from the guest room.
Exception: Guest room ventilation systems are not precluded from having an automatic daily preoccupancy 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.
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.
Ventilation, either natural or mechanical, shall be provided in accordance with Chapter 4 of the Florida Building Code, Mechanical. 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 Florida Building Code, Mechanical.
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 per 1,000 square feet (93 m2) of floor area (as established in Table 403.3.1.1 of the Florida Building Code, Mechanical) 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).
Exception: Demand control ventilation is not required for systems and spaces as follows:
  1. Systems with energy recovery complying with Section C403.2.7.
  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 for process loads only.
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 Florida Building Code, Mechanical 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.
Where the supply airflow rate of a fan system exceeds the values specified in Tables C403.2.7(1) and C403.2.7(2), the system shall include an energy recovery system. The energy recovery system shall have the capability 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 which permit operation of the economizer as required by Section C403.3.
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 Florida Building Code, Mechanical.
  2. Laboratory fume hood systems that include at least one of the following features:
    1. 2.1. Variable-air-volume hood exhaust and room supply systems capable of reducing exhaust and makeup air volume to 50 percent or less of design values.
    2. 2.2. Direct makeup (auxiliary) air supply equal to at least 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, 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 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 C403.2.7(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.
ENERGY RECOVERY REQUIREMENT (Ventilation systems operating less than 8,000 hours per year)
CLIMATE PERCENT (%) 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, 5B NR NR NR NR NR NR NR NR
1B, 2B, 5C NR NR NR NR ≥ 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 > 0
7, 8 ≥ 4,500 ≥ 4,000 ≥ 2,500 ≥ 1,000 > 0 > 0 > 0 > 0
For SI: 1 cfm = 0.4719 L/s.
NR = Not Required.
ENERGY RECOVERY REQUIREMENT (Ventilation systems operating not less than 8,000 hours per year)
CLIMATE ZONE PERCENT (%) 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)
3C NR NR NR NR NR NR NR NR
1B, 2B, 3B, 4C, 5C NR ≥ 19,500 ≥ 9,000 ≥ 5,000 ≥ 4,000 ≥ 3,000 ≥ 1,500 > 0
1A, 2A, 3A, 4B, 5B ≥ 2,500 ≥ 2,000 ≥ 1,000 ≥ 500 > 0 > 0 > 0 > 0
4A, 5A, 6A, 6B, 7, 8 > 0 > 0 > 0 > 0 > 0 > 0 > 0 > 0
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 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 factorybuilt commercial exhaust hood listed by a nationally recognized testing laboratory in compliance with UL 710. Each hood 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 capable of 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 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.
MINIMUM DUCT INSULATION R-VALUES, HEATING AND COOLING SUPPLY AND RETURN DUCTS
LOCATION SUPPLY RETURN
Exterior of building R-6 R-4.2
Ventilated Attic R-6 R-4.2
Unvented attic above insulated ceiling R-6 R-4.2
Unvented attic with roof insulation R-4.2 None
Unconditioned spacesa R-4.2 R-4.2
Indirectly conditioned spacesb None None
Conditioned spaces None None
Buried R-4.2 None
  1. Includes crawl spaces, both ventilated and nonventilated.
  2. Includes return air plenums with or without exposed roofs above.
All supply and return air ducts and plenums shall be insulated to the levels shown in Table C403.2.9.1.
Exceptions:
  1. When located within equipment.
  2. When the design temperature difference between the interior and exterior of the duct or plenum does not exceed 15°F (8°C).
  3. For runouts less than 10 feet (3048 mm) in length to air terminals or air outlets, the rated R-value of insulation need not exceed R-5.
  4. Backs of air outlets and outlet plenums exposed to unconditioned or indirectly conditioned spaces with face areas exceeding 5 square feet (.46 m2) need not exceed R-2; those 5 square feet (.46 m2) or smaller need not be insulated.
  5. Return air ducts meeting all the requirements for building cavities that will be used as return air plenums.
Insulation shall be protected from damage, including that due to sunlight, moisture, equipment maintenance and wind, but not limited to the following:
  1. Insulation exposed to weather shall be suitable for outdoor service, e.g., protected by aluminum, sheet metal, painted canvas or plastic cover. Cellular foam insulation shall be protected as above or painted with a coating that is water retardant and provides shielding from solar radiation that can cause degradation of the material.
  2. Insulation covering cooling ducts located outside the conditioned space shall include a vapor retardant located outside the insulation (unless the insulation is inherently vapor retardant), all penetrations and joints of which shall be sealed.
Additional insulation with vapor barrier shall be provided where the minimum duct insulation requirements of Section C403.2.9.1.1 are determined to be insufficient to prevent condensation.
All ducts, air handlers, filter boxes, building cavities, mechanical closets and enclosed support platforms that form the primary air containment passageways for air distribution systems shall be considered ducts or plenum chambers and shall be constructed and erected in accordance with Table C403.2.9.2 and with Chapter 6 of the Florida Building Code, Mechanical. Ducts shall be constructed, braced, reinforced and installed to provide structural strength and durability. All transverse joints, longitudinal seams and fitting connections shall be securely fastened in accordance with the applicable standards of this section.
DUCT SYSTEM CONSTRUCTION AND SEALING
DUCT TYPE/
CONNECTION
SEALING REQUIREMENTS MECHANICAL ATTACHMENT TEST STANDARD
Metal duct, rigid and
flexible
Pressures less than 1-
inch water gauge
Closure systems as described in
  1. Continuous welds.
  2. Snaplock seams and grooved, standing, double-corner, single-corner and Pittsburgh-lock seams and all other rolled mechanical seams.
  3. Mastic, mastic-plus-embedded fabric or mastic ribbons.
  4. Gaskets.
  5. Pressure-sensitive tape.
  6. Aerosol sealant.
Mechanical attachments approved:
  1. Continuous welds.
  2. Snaplock seams and grooved, standing, double corner, single-corner and Pittsburgh-lock seams and all other rolled mechanical seams.
Crimp joints for round metal ducts shall have a contact lap of at least 11/2 inches
(38 mm).
Round metal ducts shall be mechanically
fastened by means of at least three
sheet-metal screws or rivets equally
spaced around the joint.a
SMACNA HVAC Air Duct Leakage Test Manual
Pressures 1-inch water
gauge or greater
Closure systems as described in
  1. Continuous welds.
  2. Mastic or mastic-plus-embedded fabric systems.
  3. Gaskets.
Mechanical attachments approved:
Continuous welds.
Round metal ducts shall be
mechanically fastened by means of
at least three sheet-metal screws or
rivets equally spaced around the joint.a
SMACNA HVAC Air Duct Leakage Test Manual
High-pressure duct systems
designed to operate at
pressures greater than 3-inch
water gauge (4-inch water
gauge pressure class)
The tested duct leakage class, at a test pressure
equal to the design duct
pressure class rating, shall be equal to
or less than Leakage Class 6. Leakage
testing may be limited to representative
sections of the duct system but in no
case shall such tested sections include
less than 25 percent of the total
installed duct area for the designated pressure class.
SMACNA HVAC Air Duct Leakage Test Manual
Plastic duct See Section 603.8.3 of the Florida Building Code, Mechanical. Joints between plastic ducts and plastic
fittings shall be made in accordance with
the manufacturer's installation instructions.
ASTM D2412
Fibrous glass duct, rigid All joints, seams and duct wall
penetrations between sections of duct
and between duct and other distribution
system components shall be sealed with
closure systems as described in
  1. Heat-activated tapes.
  2. Pressure-sensitive tapes.
  3. Mastics or mastic-plus-embedded fabric systems.
Mechanically fastened per standard to
secure the sections independent of the
closure system(s).
NAIMA Fibrous Glass Duct Construction Standards.
Attachments of ductwork to air-handling
equipment shall be by mechanical
fasteners. Where access is limited, two
fasteners on one side shall be acceptable.
UL 181
UL 181A
Flexible duct systems, nonmetal All duct collar fittings shall have a
minimum 5/8-inch (16 mm) integral
flange for sealing to other components
and a minimum 3-inch (76 mm) shaft
for insertion into the inner duct core.
Flexible nonmetal ducts shall be joined components by either terminal or
intermediate fittings.
UL 181
UL 181B
Flexible ducts having porous inner
cores shall not be used.
Exception: Ducts having a
nonporous liner between the porous
inner core and the outer jacket.
Fastening and sealing requirements
shall be applied to such intermediate liners.
Mechanical fasteners for use with
flexible nonmetallic air ducts shall
comply with UL 181B and shall be
marked 181B-C.
See Section 603.10 of the Florida Building Code, Mechanical, for duct
support requirements.
ADC FDPIS
Duct core to duct fitting The reinforced lining shall be sealed to the duct
fitting using one of the following sealing
materials, which conforms to the approved
closure and mechanical attachment requirements
of Section C403.2.9.3:
  1. Gasketing.
  2. Mastic, mastic-plus-embedded fabric or mastic ribbons.
  3. Pressure-sensitive tape.
  4. Aerosol sealants, provided that their use is consistent with UL 181.
The reinforced core shall be mechanically
attached to the duct fitting by a drawband
installed directly over the wire-reinforced
core and the duct fitting. The duct fitting
shall extend a minimum of 2 inches (51
mm) into each section of duct core. When
the flexible duct is larger than 12 inches
(303 mm) in diameter or the design
pressure exceeds 1-inch water gauge, the
drawband shall be secured by a raised bead
or indented groove on the fitting.
Duct outer jacket to
duct collar fitting
The outer jacket of a flexible duct section shall
be secured at the juncture of the air distribution
system component and intermediate or terminal
fitting in such a way as to prevent excess
condensation. The outer jacket of a flexible duct section shall not be interposed between the flange of the duct fitting and the flexible duct, rigid fibrous glass duct board or sheet metal to which it is mated.
Duct collar fitting to rigid duct The duct collar fitting's integral flange shall be
sealed to the rigid duct board or sheet metal
using one of the following closure
systems/materials, which conforms to the
approved closure and mechanical attachment
standards of Section C403.2.9.3:
  1. Gasketing.
  2. Mastic or mastic-plus-embedded fabric systems.
  3. Mastic ribbons when used to attach a duct collar to sheet metal.
  4. Pressure-sensitive tape.
  5. Aerosol sealants, provided that their use is consistent with UL 181.
The duct collar fitting shall be
mechanically attached to the rigid duct
board or sheet metal by appropriate
mechanical fasteners, either screws,
spin-in flanges or dovetail flanges.
Terminal and intermediate
fittings.
Approved closure systems shall be as designated
by air distribution system component material
type in Section C403.2.9.3.
Fittings and joints between
dissimilar duct types
Exception: When the components of a joint are fibrous glass duct board and metal duct,
including collar fittings and metal equipment
housings, the closure systems approved for
fibrous glass duct shall be used.
Terminal fittings and
air ducts to building
envelope components
Terminal fittings and air ducts that penetrate
the building envelope shall be mechanically
attached to the structure and sealed to the
envelope component penetrated and shall use
one of the following closure systems/materials
which conform to the approved closure and
mechanical application requirements of
  1. Mastics or mastic-plus-embedded fabrics.
  2. Gaskets used in terminal fitting/grille assemblies that compress the gasket material between the fitting and the wall, ceiling or floor sheathing.
Air-handling units Air-handling units located outside the
conditioned space shall be sealed using approved
closure systems described in Section C403.2.9.3
for metallic ducts.
All air-handling units shall be
mechanically attached to other air
distribution system components.
Return plenums Building cavities that will be used as return air
plenums shall be lined with a continuous air
barrier made of durable nonporous materials. All
penetrations to the air barrier shall be sealed with
a suitable long-life mastic material.
Exception: Surfaces between the plenum and conditioned spaces from which the return/mixed air is drawn.
Roof decks above building cavities used as a
return air plenum shall be insulated to at least
R-19.
Mechanical closets All joints between the air barriers of walls,
ceiling, floor and door framing and all
penetrations of the air barrier shall be sealed to
the air barrier with approved closure systems.
Through-wall, through-floor and through-ceiling
air passageways into the closet shall be framed
and sealed to form an air-tight passageway.
Exception: Air passageways into the closet from conditioned space that are specifically designed for return airflow.
The following air barriers are approved for use in mechanical closets:
  1. One-half-inch-thick (12.7 mm) or greater gypsum wallboard, taped and sealed with joint compound over taped joints between gypsum wallboard panels.
  2. Other panelized materials having inward facing surfaces with an air porosity no greater than that of a duct product meeting Section 22 of UL 181, which are sealed on all interior surfaces to create a continuous air barrier by one of the following:
    1. Sealants complying with the product and application standards of this table for fibrous glass ductboard or
    2. A suitable long-life caulk or mastic for all applications.
Enclosed support platforms in
unconditioned spaces
Enclosed support platforms located between the
return air inlet(s) from conditioned space and the
inlet of the air-handling unit or furnace, shall
contain a duct section constructed entirely of rigid
metal, rigid fibrous glass duct board or flexible
duct, which is constructed and sealed according to
the respective requirements of Section C403.2.9.2
and insulated according to the requirements of
Section C403.2.9.1.
  1. No portion of the building structure, including adjoining walls, floors and ceilings, shall be in contact with the return air stream or function as a component of this duct section.
  2. The duct section shall not be penetrated by a refrigerant line, chase, wiring, pipe or any object other than a component of the air distribution system.
  3. Through-wall, through-floor and through-ceiling penetrations into the duct system shall contain a branch duct fabricated of rigid fibrous glass duct board or rigid metal and shall extend to and be sealed by both the duct section and the grille side wall surface.
The branch duct shall be fabricated and
attached to the duct insert in accordance
with requirements for the duct type used.
  1. Where a duct connection is made that is partially inaccessible, three screws or rivets shall be equally spaced on the exposed portion of the joint so as to prevent a hinge effect.
All ducts, air handlers, filter boxes, building cavities, mechanical closets and enclosed support platforms that form the primary air containment passageways for air distribution systems shall be sealed in accordance with the applicable criteria of this section and Table C403.2.9.2.
All joints between sections of air ducts and plenums, between intermediate and terminal fittings and other components of air distribution systems, and between sub sections of these components shall be mechanically fastened to secure the sections independently of the closure system(s).
Air distribution system components shall be sealed with approved closure systems.
Sufficient space shall be provided adjacent to all mechanical components located in or forming a part of the air distribution system to assure adequate access for: (1) construction and sealing in accordance with the requirements of Section C403.2.9, (2) inspection and (3) cleaning and maintenance. A minimum of 4 inches (102 mm) is considered sufficient space around air-handling units.
Exception: Retrofit or replacement units not part of a renovation.
Closure products shall be applied to the air barriers of air distribution system components being joined in order to form a continuous barrier or they may be applied in accordance with the manufacturer's instructions or appropriate industry installation standard where more restrictive.
The surfaces upon which closure products are to be applied shall be clean and dry in accordance with the manufacturer's installation instructions.
Approved mechanical attachments for air distribution system components include screws, rivets, welds, interlocking joints crimped and rolled, staples, twist in (screw attachment), and compression systems created by bend tabs or screw tabs and flanges or by clinching straps. Mechanical attachments shall be selected from Table C403.2.9.2 to be appropriate to the duct system type.
The following closure systems and materials are approved for air distribution construction and sealing for the applications and pressure classes shown in Table C403.2.9.2:
  1. Metal closures.
    1. Welds applied continuously along metal seams or joints through which air could leak.
    2. Snaplock seams and grooved, standing, double-corner, single-corner and Pittsburgh-lock seams, as defined by SMACNA, as well as all other rolled mechanical seams. All seams shall be rolled or crimped.
  2. Gasketing, which achieves a 25/50 flame spread/smoke-density-development rating under ASTM E84 or UL 723, provided that it is used only between mated surfaces that are mechanically fastened with sufficient force to compress the gasket and to fill all voids and cracks through which air leakage would otherwise occur.
  3. Mastic closures. Mastics shall be placed over the entire joint between mated surfaces. Mastics shall not be diluted. Approved mastics include the following:
    1. Mastic or mastic-plus-embedded fabric systems applied to fibrous glass ductboard that are listed and labeled in accordance with UL 181A, Part III.
    2. Mastic or mastic-plus-embedded fabric systems applied to nonmetal flexible duct that are listed and labeled in accordance with UL 181B, Part II.
    3. Mastic ribbons, which achieve a 25/50 flame spread/smoke density development rating under ASTM E84 or UL 723, provided that they may be used only in flange-joints and lap-joints, such that the mastic resides between two parallel surfaces of the air barrier and that those surfaces are mechanically fastened.
  4. Tapes. Tapes shall be applied such that they extend not less than 1 inch onto each of the mated surfaces and shall totally cover the joint. When used on rectangular ducts, tapes shall be used only on joints between parallel rigid surfaces and on right angle joints. Approved tapes include the following:
      1. Pressure-sensitive tapes applied to fibrous glass ductboard that are listed and labeled in accordance with UL 181A, Part I.
      2. Pressure-sensitive tapes applied to nonmetal flexible duct that are listed and labeled in accordance with UL 181B, Part I.
    1. Heat-activated tapes applied to fibrous glass ductboard that are listed and labeled in accordance with UL 181A, Part II.
  5. Aerosol sealant. Such sealants shall be installed by manufacturer-certified installers following manufacturer's instructions and shall achieve 25/50 flame spread/smoke-density-development ratings under ASTM E84 or UL 723.
Cavities in framed spaces, such as dropped soffits and walls, shall not be used to deliver air from or return air to the conditioning system unless they contain an air duct insert that is insulated in accordance with Section C403.2.9.1 and constructed and sealed in accordance with the requirements of Section C403.2.9.2 appropriate for the duct materials used.
Exception: Return air plenums beneath a roof deck that is insulated to at least R-19.
All air distribution systems shall be sized and designed in accordance with recognized engineering standards such as ACCA Manual D or other standards based on the following:
  1. Calculation of the supply air for each room shall be based on the greater of the heating load or sensible cooling load for that room.
  2. Duct size shall be determined by the supply air requirements of each room, the available static pressure and the total equivalent length of the various duct runs.
  3. Friction loss data shall correspond to the type of material used in duct construction.
Piping serving as part of a heating or cooling system shall be thermally insulated in accordance with Table C403.2.10.
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).
MINIMUM PIPE INSULATION THICKNESS (in inches)a, c
FLUID OPERATING
TEMPERATURE RANGE
AND USAGE (°F)
INSULATION CONDUCTIVITY NOMINAL PIPE OR TUBE SIZE (inches)
Conductivity
Btu • in./(h • ft2 • °F)b
Mean Rating
Temperature, °F
< 1 1 to < 11/2 11/2 to < 4 4 to < 8 ≥ 8
> 350 0.32 — 0.34 250 4.5 5.0 5.0 5.0 5.0
251 — 350 0.29 — 0.32 200 3.0 4.0 4.5 4.5 4.5
201 — 250 0.27 — 0.30 150 2.5 2.5 2.5 3.0 3.0
141 — 200 0.25 — 0.29 125 1.5 1.5 2.0 2.0 2.0
105 — 140 0.21 — 0.28 100 1.0 1.0 1.5 1.5 1.5
40 — 60 0.21 — 0.27 75 0.5 0.5 1.0 1.0 1.0
< 40 0.20 — 0.26 50 0.5 1.0 1.0 1.0 1.5
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 (25 mm).
Piping insulation exposed to the weather shall be protected from damage, including that due to 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.
Each HVAC system with a fan shall comply with the provisions of Sections C403.2.12.1 through C403.2.12.5.
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) as shown in Table C403.2.12.1(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.
FAN POWER LIMITATION
LIMIT CONSTANT VOLUME VARIABLE VOLUME
Option 1: Fan system motor nameplate hp Allowable nameplate motor hp hp ≤ CFMS • 0.0011 hp ≤ CFMS • 0.0015
Option 2: Fan system bhp Allowable fan system bhp bhp ≤ CFMS • 0.00094 + A bhp ≤ 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 C403.2.12.1(2) in. w.c.
CFMD = The design airflow through each applicable device from Table C403.2.12.1(2) in cubic feet per minute.
FAN POWER LIMITATION PRESSURE DROP ADJUSTMENT
DEVICE ADJUSTMENT
Credits
Fully ducted return and/or exhaust air systems 0.5 inch w.c. (2.15 in w.c. for laboratory and vivarium systems)
Return and/or exhaust airflow control devices 0.5 inch w.c.
Exhaust filters, scrubbers or other exhaust treatment The pressure drop of device calculated at fan system design condition
Particulate filtration credit: MERV 9 thru 12 0.5 inch w.c.
Particulate filtration credit: MERV 13 thru 15 0.9 inch. w.c.
Particulate filtration credit: MERV 16 and greater and
electronically enhanced filters
Pressure drop calculated at 2× clean filter
pressure drop at fan system design condition
Carbon and other gas-phase air cleaners Clean filter pressure drop at fan system design condition
Biosafety cabinet Pressure drop of device at fan system design condition
Energy recovery device, other than coil runaround loop (2.2 × energy recovery effectiveness) — 0.5 inch w.c. for each airstream
Coil runaround loop 0.6 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 hoods 0.35 inch w.c.
Laboratory and vivarium exhaust systems in high-rise buildings 0.25 inch w.c./100 feet of vertical duct exceeding 75 feet
Deductions
Systems without central cooling device - 0.6 in. w.c.
Systems without central heating device - 0.3 in. w.c.
Systems with central electric resistance heat - 0.2 in. 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 no larger than the first available motor size greater than the following:
  1. For fans less than 6 bhp (4476 W), 1.5 times the fan brake horsepower.
  2. For fans 6 bhp (4476 W) and larger, 1.3 times the fan brake horsepower.
    Exceptions:
    1. Fans equipped with electronic speed control devices to vary the fan airflow as a function of load.
    2. Fans with fan nameplate electrical input power of less than 0.89 kW.
    3. Systems complying with Section C403.2.12.1 fan system motor nameplate hp (Option 1).
    4. Fans with motor nameplate horsepower less than 1 hp (746 W).
Each fan and fan array shall have a fan energy index (FEI) of not less than 1.00 at the design point of operation when determined in accordance with AMCA 208 by an approved, independent testing laboratory and labeled by the manufacturer. Each fan and fan array used for a variable-air-volume system shall have an FEI of not less than 0.95 at the design point of operation as determined in accordance with AMCA 208 by an approved, independent testing laboratory and labeled by the manufacturer. The FEI for fan arrays shall be calculated in accordance with AMCA 208 Annex C.
Exceptions: The following fans are not required to have a fan energy index:
  1. Fans that are not embedded fans with motor nameplate horsepower of less than 1.0 (0.75 kW) or with a fan nameplate electrical input power of less than 0.89 kW.
  2. Embedded fans that have a motor nameplate horsepower of 5 hp (3.7 kW) or less, or with a fan system electrical input power of 4.1 kW or less.
  3. Multiple fans operated in series or parallel as the functional equivalent of a single fan that have a combined motor nameplate horse-power of 5 hp (3.7 kW) or less or with a fan system electrical input power of 4.1 kW or less.
  4. Fans that are part of equipment covered under Section C403.2.3.
  5. Fans included in an equipment package certified by an approved agency for air or energy performance.
  6. Ceiling fans, i.e., nonportable devices suspended from a ceiling or overhead structure for circulating air via the rotation of fan blades.
  7. Fans used for moving gases at temperatures above 482°F (250°C).
  8. Fans used for operation in explosive atmospheres.
  9. Reversible fans used for tunnel ventilation.
  10. Fans that are intended to operate only during emergency conditions.
  11. Fans outside the scope of AMCA 208.
Motors for fans that are not less than 1/12 hp (0.082 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 also 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 C403.2.3 or C403.2.12.
  3. Motors that comply with Section C405.7.
Controls shall be provided for fans in accordance with Sections C403.2.12.5.1 through C403.2.12.5.3.
REQUIREMENTS FOR FAN CONTROL
COOLING
SYSTEM TYPE
FAN
MOTOR SIZE
MECHANICAL
COOLING CAPACITY
DX cooling Any ≥ 65,000 Btu/h
Chilled water and
evaporative cooling
1/4 hp Any
For SI: 1 British thermal unit per hour = 0.2931 W; 1 hp = 0.746 kW.
Each cooling system listed in Table C403.2.12.5 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 period so flow 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 C403.3 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 Florida Building Code, Mechanical at low speed exceeds the air that would be delivered at the speed defined in Section C403.2.12.5, the minimum speed shall be selected to provide the required ventilation air.
Static pressure sensors used to control VAV fans shall be located such that the controller set point 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.
For systems with direct digital control of individual zones reporting to the central control panel, the static pressure set point shall be reset based on the zone requiring the most pressure. In such case, the set point 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 capable of all of the following:
  1. Automatically detecting any zone that excessively drives the reset logic.
  2. Generating an alarm to the system operation allocation.
  3. Allowing an operator to readily remove one or more zones from the reset algorithm.
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 deenergized when no occupants are present.
Refrigeration equipment performance shall be determined in accordance with sections C403.2.14.1 and C403.2.14.2 for commercial refrigerators, freezers, refrigerator-freezers, walk-in coolers, walk-in freezers and refrigeration equipment. 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.
Exception: Walk-in coolers and walk-in freezers regulated under federal law in accordance with Subpart R of 10 CFR 431.
Refrigeration equipment, defined in U.S. 10 CFR part 431.62, shall have an energy use in kWh/day not greater than the values of Table C403.2.14.1(1) when tested and rated in accordance with AHRI Standard 1200.
MINIMUM EFFICIENCY REQUIREMENTS: COMMERCIAL REFRIGERATORS AND FREEZERS AND REFRIGERATION
Equipment CategoryCondensing
Unit
Configuration
Equipment
Familya
Rating
Temp (°F)
Operating
Temp (°F)
Equipment
Classificationc
Maximum Daily Energy
Consumption (kWh/day)d, e
Test
Standard
Remote Condensing Commercial Refrigera tors and Commercial FreezersRemote (RC)Vertical Open (VOP)38 (M)≥ 32VOP.RC.M0.64 × TDA + 4.07AHRI 1200
0 (L)< 32VOP.RC.L2.20 × TDA + 6.85
Semivertical Open (SVO)38 (M)≥ 32SVO.RC.M0.66 × TDA + 3.18
0 (L)< 32SVO.RC.L2.20 × TDA + 6.85
Horizontal Open (HZO)38 (M)≥ 32HZO.RC.M0.35 × TDA + 2.88
0 (L)< 32HZO.RC.L0.55 × TDA + 6.88
Vertical Closed Transparent (VCT)38 (M)≥ 32VCT.RC.M0.15 × TDA + 1.95
0 (L)< 32VCT.RC.L0.49 × TDA + 2.61
Horizontal Closed Transparent (HCT)38 (M)≥ 32HCT.RC.M0.16 × TDA + 0.13
0 (L)< 32HCT.RC.L0.34 × TDA + 0.26
Vertical Closed Solid (VCS)38 (M)≥ 32VCS.RC.M0.10 × V + 0.26
0 (L)< 32VCS.RC.L0.21 × V + 0.54
Horizontal Closed Solid (HCS)38 (M)≥ 32HCS.RC.M0.10 × V+ 0.26
0 (L)< 32HCS.RC.L0.21 × V + 0.54
Service Over Counter (SOC)38 (M)≥ 32SOC.RC.M0.44 × TDA + 0.11
0 (L)< 32SOC.RC.L0.93 × TDA + 0.22
Self-Contained Commercial Refrigerators and Commercial Freezers with and Without DoorsSelf-Contained (SC)Vertical Open (VOP)38 (M)≥ 32VOP.SCSV.M1.69 × TDA + 4.71AHRI 1200
0 (L)< 32VOP.SC.L4.25 × TDA + 1.82
Semivertical Open (SVO)38 (M)≥ 32SVO.SC.M1.70 × TDA + 4.59
0 (L)< 32SVO.SC.L4.26 × TDA +11.51
Horizontal Open (HZO)38 (M)≥ 32HZO.SC.M0.72 × TDA + 5.55
0 (L)< 32HZO.SC.L1.90 × TDA + 7.08
Vertical Closed Transparent (VCT)38 (M)≥ 32VCT.SC.M0.10 × V + 0.86
0 (L)< 32VCT.SC.L0.29 × V + 2.95
Vertical Closed Solid (VCS)38 (M)≥ 32VCS.SC.M0.05 × V + 1.36
0 (L)< 32VCS.SC.L0.22 × V + 1.38
Horizontal Closed Transparent (HCT)38 (M)≥ 32HCT.SC.M0.06 × V + 0.37
0 (L)< 32HCT.SC.L0.08 × V + 1.23
Horizontal Closed Solid (HCS)38 (M)≥ 32HCS.SC.M0.05 × V + 0.91
0 (L)< 32HCS.SC.L0.06 × V + 1.12
Service Over Counter (SOC)38 (M)≥ 32SOC.SC.M0.52 × TDA + 1.00
0 (L)< 32SOC.SC.L1.10 × TDA + 2.10
Self-Contained Commercial Refrigerators with Transparent Doors for Pull-Down Tempera ture ApplicationsSelf-Contained (SC)Pull-Down (PD)38 (M)≥ 32PD.SC.M0.11 × V + 0.81AHRI 1200
Commercial Ice-Cream FreezersRemote (RC)Vertical Open (VOP)-15 (I)≤ -5bVOP.RC.I2.79 × TDA + 8.70AHRI 1200
Semivertical Open (SVO)-15 (I)≤ -5bSVO.RC.I2.79 × TDA + 8.70
Horizontal Open (HZO)-15 (I)≤ -5bHZO.RC.I0.7 × TDA + 8.74
Vertical Closed Transparent (VCT)-15 (I)≤ -5bVCT.RC.I0.58 × TDA + 3.05
Horizontal Closed Transparent (HCT)-15 (I)≤ -5bHCT.RC.I0.4 × TDA + 0.31
Vertical Closed Solid (VCS)-15 (I)≤ -5bVCS.RC.I0.25 × V + 0.63
Horizontal Closed Solid (HCS)-15 (I)≤ -5bHCS.RC.I0.25 × V + 0.63
Service Over Counter (SOC)-15 (I)≤ -5bSOC.RC.I1.09 × TDA + 0.26
Self-Contained (SC)Vertical Open (VOP)-15 (I)≤ -5bVOP.SC.I5.4 × TDA + 15.02AHRI 1200
Semivertical Open (SVO)-15 (I)≤ -5bSVO.SC.I5.41 × TDA + 14.63
Horizontal Open (HZO)-15 (I)≤ -5bHZO.SC.I2.42 × TDA + 9.00
Vertical Closed Transparent (VCT)-15 (I)≤ -5bVCT.SC.I0.62 × TDA + 3.29
Horizontal Closed Transparent (HCT)-15 (I)≤ -5bHCT.SC.I0.56 × TDA + 0.43
Vertical Closed Solid (VCS)-15 (I)≤ -5bVCS.SC.I0.34 × V + 0.88
Horizontal Closed Solid (HCS)-15 (I)≤ -5bHCS.SC.I0.34 × V + 0.88
Service Over Counter (SOC)-15 (I)≤ -5bSOC.SC.I1.53 × TDA + 0.36
  1. The meaning of the letters in this column is indicated in the columns to the left.
  2. Ice-cream freezer is defined in 10 CFR 431.62 as a commercial freezer that is designed to operate at or below -5°F and that the manufacturer designs, markets, or intends for the storing, displaying, or dispensing of ice cream.
  3. Equipment class designations consist of a combination [in sequential order separated by periods (AAA).(BB).(C)] of the following: (AAA)—An equipment family code (VOP = vertical open, SVO = semivertical open, HZO = horizontal open, VCT = vertical closed transparent doors, VCS = vertical closed solid doors, HCT = horizontal closed transparent doors, HCS = horizontal closed solid doors and SOC = service over counter); (BB)—An operating mode code (RC = remote condensing and SC = self-contained); and (C)—A rating temperature code [M = medium temperature (38°F), L = low temperature (0°F) or I = ice cream temperature (-15°F)]. For example, "VOP.RC.M" refers to the vertical open, remote condensing, medium temperature equipment class.
  4. V is the volume of the case (in cubic feet) as measured in AHRI Standard 1200, Appendix C.
  5. TDA is the total display area of the case (in square feet) as measured in AHRI Standard 1200, Appendix D.
Walk-in cooler and walk-in freezer refrigeration systems, except for walk-in process cooling refrigeration systems as defined in U.S. 10 CFR 431.302, shall meet the requirements of Tables C403.2.14.2(1), C403.2.14.2(2) and C403.2.14.2(3).
WALK-IN COOLER AND FREEZER DISPLAY DOOR EFFICIENCY REQUIREMENTSa
CLASS DESCRIPTOR CLASS MAXIMUM ENERGY CONSUMPTION (kWh/day)
Display door, medium temperature DD, M 0.04 × Add + 0.41
Display door, low temperature DD, L 0.15 × Add + 0.29
  1. Add is the surface area of the display door.
WALK-IN COOLER AND FREEZER NONDISPLAY DOOR EFFICIENCY REQUIREMENTSa
CLASS DESCRIPTOR CLASS MAXIMUM ENERGY CONSUMPTION (kWh/day)
Passage door, medium temperature PD, M 0.05 × And + 1.7
Passage door, low temperature PD, L 0.14 × And + 4.8
Freight door, medium temperature FD, M 0.04 × And + 1.9
Freight door, low temperature FD, L 0.12 × And + 5.6
  1. And is the surface area of the display door.
WALK-IN COOLER AND FREEZER REFRIGERATION SYSTEMS EFFICIENCY REQUIREMENTS (CE126-16AM)
CLASS DESCRIPTOR CLASS MINIMUM ANNUAL WALK-IN
ENERGY FACTOR AWEF (Btu/W-h)a
TEST PROCEDURE
Dedicated condensing, medium temperature, indoor system DC.M.I 5.61 AHRI 1250
Dedicated condensing, medium temperature, outdoor system DC.M.O 7.60
Dedicated condensing, low temperature, indoor system, net capacity (qnet) < 6,500 Btu/h DC.L.I, < 6,500 9.091 × 10-5 × qnet + 1.81
Dedicated condensing, low temperature, indoor system, net capacity (qnet) ≥ 6,500 Btu/h DC.L.I, ≥ 6,500 2.40
Dedicated condensing, low temperature, outdoor system, net capacity (qnet) < 6,500 Btu/h DC.L.O, < 6,500 6.522 × 10-5 × qnet + 2.73
Dedicated condensing, low temperature, outdoor system, net capacity (qnet) ≥ 6,500 Btu/h DC.L.O, ≥ 6,500 3.15
Unit cooler, medium UC.M 9.00
Unit cooler, low temperature, net capacity (qnet) < 15,500 Btu/h UC.L, < 15,500 Btu/h 1.575 × 10-5 × qnet + 3.91
Unit cooler, low temperature, net capacity (qnet) ≥ 15,500 Btu/h UC.L, ≥ 15,500 Btu/h 4.15
  1. qnet is net capacity (Btu/hr) as determined in accordance with AHRI Standard 1250.
Each cooling system shall include either an air or water economizer complying with Sections C403.3.1 through C403.3.4.
Exceptions: Economizers are not required for the systems listed below.
  1. In cooling systems for buildings located in Climate Zones 1A and 1B.
  2. In climate zones other than 1A and 1B, where individual fan cooling units have a capacity of less than 54,000 Btu/h (15.8 kW) and meet one of the following:
    1. 2.1. Have direct expansion cooling coils.
    2. 2.2. The total chilled water system capacity less the capacity of fan units with air economizers is less than the minimum specified in Table C403.3(1).
    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. 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) dewpoint temperature to satisfy process needs.
  4. Systems that serve residential spaces where the system capacity is less than five times the requirement listed in Table C403.3(1).
  5. Systems expected to operate less than 20 hours per week.
  6. Where the use of outdoor air for cooling will affect supermarket open refrigerated casework systems.
  7. The required air or water economizer may be eliminated if the minimum code required cooling efficiency of the HVAC unit rated with an IPLV, IEER or SEER is increased by at least 17 percent. If the HVAC unit is only rated with a full-load metric like EER cooling, then it must be increased by at least 17 percent.
  8. Chilled-water cooling systems that are passive (without a fan) or use induction where the total chilled water system capacity less the capacity of fan units with air economizers is less than the minimum specified in Table C403.3(1).
  9. Systems that include a heat recovery system in accordance with Section C403.4.5.
MINIMUM CHILLED-WATER SYSTEM COOLING CAPACITY FOR DETERMINING ECONOMIZER COOLING REQUIREMENTS
(COOLING) TOTAL CHILLED-WATER SYSTEM CAPACITY LESS CAPACITY OF COOLING UNITS WITH AIR ECONOMIZERS
Local Water-cooled
Chilled-water Systems
Air-cooled Chilled-water Systems
or District Chilled-Water Systems
1a No economizer requirement No economizer requirement
1b, 2a, 2b 960,000 Btu/h 1,250,000 Btu/h
3a, 3b, 3c, 4a, 4b, 4c 720,000 Btu/h 940,000 Btu/h
5a, 5b, 5c, 6a, 6b, 7, 8 1,320,000 Btu/h 1,720,000 Btu/h
For SI: 1 British thermal unit per hour = 0.2931 W.
Table C403.3(2) Equipment Efficiency Performance Exception for Economizers.
Reserved.
Economizer systems shall be integrated with the mechanical cooling system and be capable of providing 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 C403.3.1.
DX COOLING STAGE REQUIREMENTS FOR MODULATING AIRFLOW UNITS
RATING CAPACITY
MINIMUM NUMBER
OF MECHANICAL COOLING STAGES
MINIMUM
COMPRESSOR DISPLACEMENTa
≥ 65,000 Btu/h and
< 240,000 Btu/h
3 stages ≤ 35% of full load
≥ 240,000 Btu/h 4 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 due to a reduction in supply air temperature.
Air economizer systems shall be capable of modulating outdoor air and return air dampers to provide up to 100 percent of the design supply air quantity as outdoor air for cooling.
Economizer dampers shall be capable of being sequenced 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 capable of automatically reducing outdoor air intake to the design minimum outdoor air quantity when outdoor air intake will no longer reduce cooling energy usage. High-limit shutoff control types for specific climates shall be chosen from Table C403.3.3.3. Highlimit shutoff control settings for these control types shall be those specified in Table C403.3.3.3.
HIGH-LIMIT SHUTOFF CONTROL SETTING FOR AIR ECONOMIZERSb
DEVICE TYPE CLIMATE ZONE
REQUIRED HIGH LIMIT
(ECONOMIZER OFF WHEN):
Equation Description
Fixed dry bulb
1B, 2B, 3B, 3C, 4B, 4C,
5B, 5C, 6B, 7, 8
TOA > 75°F Outdoor air temperature exceeds 75°F
5A, 6A TOA > 70°F Outdoor air temperature exceeds 70°F
1A, 2A, 3A, 4A TOA > 65°F Outdoor air temperature exceeds 65°F
Differential dry bulb
1B, 2B, 3B, 3C, 4B, 4C, 5A,
5B, 5C, 6A, 6B, 7, 8
TOA > TRA Outdoor air temperature exceeds
return air temperature
Fixed enthalpy with fixeddry-bulb temperatures
All
hOA > 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
All
hOA > 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 C403.2.4.3.
Water-side economizers shall comply with Sections C403.3.4.1 and C403.3.4.2.
Water economizer systems shall be capable of cooling 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 which 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 waterside 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.
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 C403.4.2.1 through C403.4.2.3. 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 capable of sequencing operation of the boilers. Hydronic heating systems comprised 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 dead band 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 pumps connected to a common heat pump water loop with central devices for heat rejection and heat addition shall have controls that are capable of providing a heat pump water supply temperature dead band 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 realtime conditions of demand and capacity, dead bands of less than 20°F (11°C) shall be permitted.
Heat rejection equipment shall comply with Sections C403.4.2.3.2.1 and C403.4.2.3.2.2.
Exception: Where it can be demonstrated that a heat pump system will be required to reject heat throughout the year.
For Climate Zones 3 and 4:
  1. Where a closed-circuit cooling tower is used directly in the heat pump loop, either an automatic valve shall be installed to bypass all but a minimal flow of water around the tower, or lower leakage positive closure dampers shall be provided.
  2. Where an open-circuit tower is used directly in the heat pump loop, an automatic valve shall be installed to bypass all heat pump water flow around the tower.
  3. Where an open- or closed-circuit cooling tower is used in conjunction with a separate heat exchanger to isolate the cooling tower from the heat pump loop, then heat loss shall be controlled by shutting down the circulation pump on the cooling tower loop.
For Climate Zones 5 through 8, where an open- or closed-circuit cooling tower is used, a separate heat exchanger shall be provided to isolate the cooling tower from the heat pump loop, and heat loss shall be controlled by shutting down the circulation pump on the cooling tower loop and providing an automatic valve to stop the flow of fluid.
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 500,000 Btu/h (146.5 kW) in design output capacity supplying heated or chilled water to comfort conditioning systems shall include controls that have the capability 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 capable of being 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 motor capacity of 10 hp (7.5 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 by designed 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 chilled-water systems and heat rejection loops serving watercooled unitary air conditioners with a combined motor capacity of 10 hp (7.5 kW) or larger by reducing pump design flow by not less than 50 percent, utilizing adjustable speed drives on pumps, or multiple-staged pumps where not less than one-half of the total pump horsepower is capable of being automatically turned off. 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 for chilled-water systems supplied by off-site district chilled water or chilled water from ice storage systems.
  2. Minimum flow rates other than 50 percent as required by the equipment manufacturer for proper operation of equipment where using flow bypass or end-of-line 3-way valves.
  3. Variable pump flow 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.
Boiler systems with design input of greater than 1,000,000 Btu/h (293 kW) shall comply with the turndown ratio specified in Table C403.4.2.5.
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.
BOILER TURNDOWN
BOILER SYSTEM DESIGN INPUT (Btu/h)
MINIMUM
TURNDOWN
RATIO
≥ 1,000,000 and less than or equal to 5,000,000 3 to 1
> 5,000,000 and less than or equal to 10,000,000 4 to 1
> 10,000,000 5 to 1
For SI: 1 British thermal unit per hour = 0.2931 W.
Chilled water plants including more than one chiller shall have the capability 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 plants including more than one boiler shall have the capability to reduce flow automatically through the boiler plant when a boiler is shut down.
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 C403.2.3(6) and C403.2.3(7).
Each fan system powered by an individual motor or array of motors with a 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 C403.2.3(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.
Sections C403.4.4.1 through C403.4.4.7 shall apply to complex mechanical systems serving multiple zones. Supply air systems serving multiple zones shall be variable air volume (VAV) systems that, during periods of occupancy, are designed and capable of being controlled to reduce primary air supply to each zone to one of the following before reheating, recooling or mixing takes place:
  1. Thirty percent of the maximum supply air to each zone.
  2. Three hundred cfm (142 L/s) or less where the maximum flow rate is less than 10 percent of the total fan system supply airflow rate.
  3. The minimum ventilation requirements of Chapter 4 of the Florida Building Code, Mechanical.
  4. Any higher rate that can be demonstrated to reduce overall system annual energy use by offsetting reheat/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 or site-solar energy source.
  2. Zones where special humidity levels are required to satisfy process needs.
  3. Zones with a peak supply air quantity of 300 cfm (142 L/s) or less and where the flow rate is less than 10 percent of the total fan system supply airflow rate.
  4. Zones where the volume of air to be reheated, recooled or mixed is not greater than the volume of outside air required to provide the minimum ventilation requirements of Chapter 4 of the Florida Building Code, Mechanical.
  5. Zones or supply air systems with thermostatic and humidistatic controls capable of operating in sequence the supply of heating and cooling energy to the zones and which are capable of preventing 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 reducing 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 capable of reducing the flow from one duct to a minimum before mixing of air from the other duct takes place.
Individual dual-duct or mixing heating 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 capable of resetting 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 Florida Building Code, Mechanical.
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.
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 watercooled 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.
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 C403.4.6, as limited by Section C403.3.1.
MAXIMUM HOT GAS BYPASS CAPACITY
RATED CAPACITY
MAXIMUM HOT GAS BYPASS CAPACITY
(% of total capacity)
≤ 240,000 Btu/h 50
> 240,000 Btu/h 25
For SI: 1 British thermal unit per hour = 0.2931 W.
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 C403.5.1 and C403.5.2.
Exception: Systems where the working fluid in the refrigeration cycle goes through both subcritical and supercritical 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 drybulb 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 C403.2.10.
  3. Compressors that incorporate internal or external crankcase heaters shall provide a means to cycle the heaters off during compressor operation.
The condensing coil of one air-conditioning unit shall not be installed in the cool air stream of another air-conditioning unit.
Exceptions:
  1. Where condenser heat reclaim is used in a properly designed system including enthalpy control devices to achieve requisite humidity control for process, special storage or equipment spaces and occupant comfort within the criteria of ASHRAE Standard 55. Such systems shall result in less energy use than other appropriate options.
  2. For computer or clean rooms whose location precludes the use of systems that would not reject heat into conditioned spaces.
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 also intended to be used to provide space heating shall meet the applicable provisions of Table C404.2.
MINIMUM PERFORMANCE OF WATER-HEATING EQUIPMENT
EQUIPMENT TYPE SIZE CATEGORY
(input)
SUBCATEGORY OR
RATING CONDITION
DRAW
PATTERN
PERFORMANCE
REQUIREDa, b, g
TEST
PROCEDURE
Storage water heaters,
electric
≤ 12 kWd Tabletope,
≥ 20 gallons and
≤ 120 gallons
Very small
Low
Medium
High
0.6323 - (0.0058 × V), UEF
0.9188 - (0.0031 × V), UEF
0.9577 - (0.0023 × V), UEF
0.9884 - (0.0016 × V), UEF
DOE 10 CFR Part 430
≥ 20 gallons and
≤ 55 gallons
Very small
Low
Medium
High
0.8808 - (0.0008 × V), UEF
0.9254 - (0.0003 × V), UEF
0.9307 - (0.0002 × V), UEF
0.9349 - (0.0001 × V), UEF
> 55 gallons and
≤ 120 gallons
Very small
Low
Medium
High
1.9236 - (0.0011 × V), UEF
2.0440 - (0.0011 × V), UEF
2.1171 - (0.0011 × V), UEF
2.2418 - (0.0011 × V), UEF
Grid-enabledf
> 75 gallons
Very small
Low
Medium
High
1.0136 - (0.0028 × V), UEF
0.9984 - (0.0014 × V), UEF
0.9853 - (0.0010 × V), UEF
0.9720 - (0.0007 × V), UEF
> 12 kW All (0.3 + 27/Vm), SL, %/h DOE 10 CFR Part 431
Instantaneous electric < 2 gal Very small
Low
Medium
High
0.91, UEF
0.91, UEF
0.91, UEF
0.92, UEF
DOE 10 CFR Part 430
> 12 kW and
≤ 58.6 kW
Residential-duty
commercial
≤ 2 gal
Very small
Low
Medium
High
0.80, UEF
0.80, UEF
0.80, UEF
0.80, UEF
DOE 10 CFR Part 431
Storage water heaters, gas ≤ 75,000 Btu/h ≥ 20 gallons and
≤ 55 gallons
Very small
Low
Medium
High
0.3456 - (0.0020 × V), UEF
0.5982 - (0.0019 × V), UEF
0.6483 - (0.0017 × V), UEF
0.6920 - (0.0013 × V), UEF
DOE 10 CFR Part 430
> 55 gallons and
≤ 100 gallons
Very small
Low
Medium
High
0.6470 - (0.0006 × V), UEF
0.7689 - (0.0005 × V), UEF
0.7897 - (0.0004 × V), UEF
0.8072 - (0.0003 × V), UEF
> 75,000 Btu/h < 4,000 Btu/h/gal DOE 10 CFR Part 431
> 75,000 Btu/h and
≤ 105,000 Btu/h
Residential-duty
commercial
≤ 120 gal
Very small
Low
Medium
High
0.2674 - (0.0009 × V), UEF
0.5362 - (0.0012 × V), UEF
0.6002 - (0.0011 × V), UEF
0.6597 - (0.0009 × V), UEF
Instantaneous gas