CODES

ADOPTS WITH AMENDMENTS:

International Energy Conservation Code 2009 (IECC 2009)

  1. Introduction. The increased energy efficiency measures identified in this appendix are strictly voluntary at the option of the permit holder and have been evaluated to be the most cost effective measures for achieving an additional 15-20% energy efficiency beyond the code minimums.
  2. Requirements: Follow all sections of the Chapter 4 of the North Carolina Energy Conservation Code, except the following.

    1. Instead of using Table 402.1.1 in Section 402.1.1, use Table E-4A shown below.

      TABLE 4A
      INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa
      CLIMATE
      ZONE
      FENESTRATION
      U-FACTORb
      SKYLIGHTb
      U-FACTOR
      GLAZED
      FENESTRATION
      SHGCb,e
      CEILING
      R-VALUEk
      WOOD
      FRAME
      WALL
      R-VALUEe
      MASS
      WALL
      R-VALUEi
      FLOOR
      R-VALUE
      BASEMENTc
      WALL
      R-VALUE
      SLABd
      R-VALUE
      CRAWL
      SPACEc
      WALL
      R-VALUE
      3 0.32j 0.65 0.25 38 19, 13+5,
      or 15+3e,h
      5/10 19 10/13f 5 10/13
      4 0.32 0.60 0.25 38 19, 13+5,
      or 15+3e,h
      5/10 19 10/13 10 10/13
      5 0.32 0.60 (NR) 38 19, 13+5
      or 15+3e,h
      13/17 30g 10/13 10 15/19
      For SI: 1 foot = 304.8 mm.
      1. R-values are minimums. U-factors and SHGC are maximums.
      2. The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestration.
      3. “10/13” means R-10 continuous insulated sheathing on the interior or exterior of the home or R-13 cavity insulation at the interior of the basement wall or crawl space wall.
      4. For monolithic slabs, insulation shall be applied from the inspection gap downward to the bottom of the footing or a maximum of 18 inches below grade, whichever is less . For floating slabs, insulation shall extend to the bottom of the foundation wall or 24 inches, whichever is less. (See Appendix O) R-5 shall be added to the required slab edge R-values for heated slabs.
      5. R-19 fiberglass batts compressed and installed in a nominal 2 × 6 framing cavity is deemed to comply. Fiberglass batts rated R-19 or higher compressed and installed in a 2 × 4 wall is not deemed to comply.
      6. Basement wall insulation is not required in warm-humid locations as defined by Figure 301.2 and Tables 301.1 and 301.3.
      7. Or insulation sufficient to fill the framing cavity, R-19 minimum.
      8. “13+5” means R-13 cavity insulation plus R-5 insulated sheathing. 15+3 means R-15 cavity insulation plus R-3 insulated sheathing. If structural sheathing covers 25 percent or less of the exterior, insulating sheathing is not required where structural sheathing is used. If structural sheathing covers more than 25 percent of exterior, structural sheathing shall be supplemented with insulated sheathing of at least R-2. 13+2.5 means R-13 cavity insulation plus R-2.5 sheathing.
      9. For Mass Walls, the second R-value applies when more than half the insulation is on the interior of the mass wall.
      10. R-30 shall be deemed to satisfy the ceiling insulation requirement wherever the full height of uncompressed R-30 insulation extends over the wall top plate at the eaves. Otherwise R-38 insulation is required where adequate clearance exists or insulation must extend to either the insulation baffle or within 1" of the attic roof deck.
      11. Table value required except for roof edge where the space is limited by the pitch of the roof, there the insulation must fill the space up to the air baffle.
    2. Instead of using Table 402.1.3 in Section 402.1.3, use Table E-4B to find the maximum U-factors for building components.

    3. TABLE 4B
      EQUIVALENT U-FACTORSa
      CLIMATE
      ZONE
      FENESTRATION
      U-FACTOR
      SKYLIGHT
      U-FACTOR
      CEILING
      U-FACTOR
      FRAME WALL
      U-FACTOR
      MASS WALL
      U-FACTORb
      FLOOR
      U-FACTOR
      BASEMENT
      WALL
      U-FACTORd
      CRAWL SPACE
      WALL
      U-FACTORc
      3 0.32 0.65 0.030 0.061 0.141 0.047 0.059 0.065
      4 0.32 0.60 0.030 0.061 0.141 0.047 0.059 0.065
      5 0.32 0.60 0.030 0.061 0.082 0.033 0.059 0.055
      1. Nonfenestration U-factors shall be obtained from measurement, calculation or an approved source.
      2. When more than half the insulation is on the interior, the mass wall U-factors shall be a maximum 0.12 in Zone 3, 0.10 in Zone 4, and the same as the frame wall U-factor in Zone 5.
      3. Basement wall U-factor of 0.360 in warm-humid locations as defined by Table 301.1 and Figure 301.2.
      4. Foundation U-factor requirements shown in Table 4B include wall construction and interior air films but exclude soil conductivity and exterior air films. U-factors for determining code compliance in accordance with Section 402.1.4 (total UA alternative) shall be modified to include soil conductivity and exterior air films.
    4. Instead of using the air leakage value for maximum leakage shown in Section 402.4.2.2, use the following:

      1. 0.24 CFM50/Square Foot of Surface Area (SFSA) or
      2. Four (4) air changes per hour (ACH50)
    5. Instead of using the duct leakage value for maximum leakage shown in Section 403.2.2, use the following:

      Total duct leakage or leakage to the outside shall be less than or equal to 4 CFM (12 L/min) per 100 ft2 (9.29 m2) of conditioned floor area served by that system when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across
NORTH CAROLINA ENERGY CONSERVATION CODE:
HIGH EFFICIENCY RESIDENTIAL OPTION
INSULATION AND FENESTRATION VALUES
PROPOSED
PROJECT VALUES
Climate Zone
3 4 5
Fenestration U-Factor 0.32j 0.32j 0.32j
Skylight U-Factor 0.65 0.6 0.6
Glazed Fenestration SHGCb, e 0.25 0.25 NR
Ceiling R-value 38 38 38
Wood Frame Wall R-valuee 19, 13+5, or
15+3eh
19, 13+5, or
15+3eh
19, 13+5, or
15+3eh
Mass Wall R-valuej 5/10 5/10 13/17
Floor R-value 19 19 30g
Basement Wall R-valuec 10/13f 10/13f 10/13f
Slab R-value and Depthd 5, 2 ft 10, 2 ft 10, 2 ft
Crawl Space Wall R-valuec 10/13 10/13 15/19
Building Air Leakage
Visually inspected according to
N1102.4.2.1 (check box) OR
Building Air Leakage Test
according to N1102.4.2.2
(check box). Show test value:
ACH50 [Target: 4.0], or
CFM50/SFSA [Target: 0.24]
Name of Tester / Company:
Date:
Duct Insulation and Sealing
Insulation Value R-
Duct Leakage Test Result
(Sect. N1103.2.2)
(CFM25 Total/100SF)
[Target:4]
Name of Tester or Company:
Date:


4D:
SAMPLE WORKSHEETS FOR RESIDENTIAL AIR AND DUCT LEAKAGE TESTING
4D.1
Air sealing: Visual inspection option (Section 402.4.2.1)
Sample Worksheet for Alternative Residential Energy Code for Higher Efficiency

402.4.2 Air sealing. Building envelope air tightness shall be demonstrated by Section 402.4.2.1 or 402.4.2.2:

402.4.2.1 Visual inspection option. Building envelope tightness shall be considered acceptable when items providing insulation enclosure in Section 402.2.12 and air sealing in Section 402.4.1 are addressed and when the items listed in Table 402.4.2, applicable to the method of construction, are certified by the builder, permit holder or registered design professional via the certificate in Appendix 1.1.

COMPONENT CRITERIA
Ceiling/attic Sealants or gaskets provide a continuous air barrier system joining the top plate of framed walls with either the ceiling drywall or the top edge of wall drywall to prevent air leakage. Top plate penetrations
are sealed.

  For ceiling finishes that are not air barrier systems such as tongue-and-groove planks, air barrier
systems; (for example, taped house wrap), shall be used above the finish.

  Note: It is acceptable that sealants or gaskets applied as part of the application of the drywall will not
Walls Sill plate is gasketed or sealed to subfloor or slab.
Windows and doors Space between window and exterior door jambs and framing is sealed.
Floors (including above-garage and cantilevered floors) Air barrier system is installed at any exposed edge of insulation.
Penetrations Utility penetrations through the building thermal envelope, including those for plumbing, electrical wiring, ductwork, security and fire alarm wiring, and control wiring, shall be sealed.
Garage separation Air sealing is provided between the garage and conditioned spaces. An air barrier system shall be installed between the ceiling system above the garage and the ceiling system of interior spaces.
Duct boots Sealing HVAC register boots and return boxes to subfloor or drywall.
Recessed lighting Recessed light fixtures are air tight, IC rated, and sealed to drywall.

  Exception—fixtures not penetrating the building envelope.


Property Address:
______________________________________________________________________________


402.4.2.1 Visual inspection option
The inspection information including tester name, date, and contact shall be included on the certificate described in Section 401.3.

________________________________________________    ___________________________
Signature                                                                              Date




4D.2
Air sealing: Testing option (Section 402.4.2.2)
Sample Worksheet for Alternative Residential Energy Code for Higher Efficiency

402.4.2 Air sealing. Building envelope air tightness shall be demonstrated by Section 402.4.2.1 or 402.4.2.2:

402.4.2.2 Testing option. Building envelope tightness shall be considered acceptable when items providing insulation enclosure in Section 402.2.12 and air sealing in Section 402.4.1 are addressed and when tested air leakage is less than or equal to one of the two following performance measurements:
  1. 0.24 CFM50/Square Foot of Surface Area (SFSA) or
  2. Four (4) air changes per hour (ACH50)
   When tested with a blower door fan assembly, at a pressure of 33.5 psf (50 Pa). A single point depressurization, not temperature corrected, test is sufficient to comply with this provision, provided that the blower door fan assembly has been certified by the manufacturer to be capable of conducting tests in accordance with ASTM E 779-03. Testing shall occur after rough in and after installation of penetrations of the building envelope, including penetrations for utilities, plumbing, electrical, ventilation and combustion appliances. Testing shall be reported by the permit holder, a NC licensed general contractor, a NC licensed HVAC contractor, a NC licensed Home Inspector, a registered design professional, a certified BPI Envelope Professional or a certified HERS rater.

During testing:
  1. Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed;
  2. Dampers shall be closed, but not sealed, including exhaust, backdraft, and flue dampers;
  3. Interior doors shall be open;
  4. Exterior openings for continuous ventilation systems, air intake ducted to the return side of the conditioning system, and energy or heat recovery ventilators shall be closed and sealed;
  5. Heating and cooling system(s) shall be turned off; and
  6. Supply and return registers shall not be sealed.

   The air leakage information, including building air leakage result, tester name, date, and contact information, shall be included on the certificate described in Section 401.3.

For Test Criteria 1 above, the report shall be produced in the following manner: Perform the blower door test and record the CFM50___________. Calculate the total square feet of surface area for the building thermal envelope, all floors, ceilings, and walls (this includes windows and doors) and record the area______________. Divide CFM50 by the total square feet and record the result below. If the result is less than or equal to [0.30 CFM50/SFSA] the envelope tightness is acceptable; or

For Test Criteria 2 above, the report shall be produced in the following manner: Perform a blower door test and record the CFM50___________. Multiply the CFM50 by 60 minutes to create CFHour50 and record ______________. Then calculate the total conditioned volume of the home and record_________________. Divide the CFH50 by the total volume and record the result below. If the result is less than or equal to [5 ACH50] the envelope tightness is acceptable.

Property Address: _____________________________________________________________________________________________

Fan attachment location: _____________________________Company Name: _____________________________________

Contact Information: __________________________________________________________________________________________

____________________________________________________     ___________________
Signature of Tester                                                                 Date



Permit Holder, NC Licensed General Contractor, NC Licensed HVAC Contractor, NC Licensed Home Inspector, Registered Design Professional, Certified BPI Envelope Professional, or Certified HERS Rater
(circle one)


4D.3
Duct sealing. Duct air leakage test (Section 403.2.2)
Sample Worksheet for Alternative Residential Energy Code for Higher Efficiency

403.2.2 Sealing. All ducts, air handlers, filter boxes and building cavities used as ducts shall be sealed. Joints and seams shall comply with Part V – Mechanical, Section 603.9 of the North Carolina Residential Code.

Duct tightness shall be verified using one of the two following methods:

1) Total duct leakage. Total duct leakage less than or equal to 4 CFM (12 L/min) per 100 ft2 (9.29 m2) of conditioned floor area served by that system when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the entire system, including the manufacturer’s air handler enclosure.

During testing:
  1. Block, if present, the ventilation air duct(s) connected to the conditioning system.
  2. The duct air leakage testing equipment shall be attached to the largest return in the system or to the air handler.
  3. The filter shall be removed and the air handler power shall be turned off.
  4. Supply boots or registers and return boxes or grilles shall be taped, plugged, or otherwise sealed air tight.
  5. The hose for measuring the 25 Pascals of pressure differential shall be inserted into the boot of the supply that is nominally closest to the air handler.
  6. Specific instructions from the duct testing equipment manufacturer shall be followed to reach duct test pressure and measure duct air leakage.

2) Duct leakage to the outside. Conduct the test using fan pressurization of distribution system and building at a fixed reference pressure for combined supply and return leaks. Duct leakage to the outside shall be less than or equal to 4 CFM (12 L/min) per 100 ft2 (9.29 m2) of conditioned floor area served by that system when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the entire system, relative to the outside, including the manufacturer’s air handler enclosure.

During testing:
  1. Block, if present, the ventilation air duct(s) connected to the conditioning system.
  2. The duct air leakage testing equipment shall be attached to the largest return in the system or to the air handler.
  3. The filter shall be removed and the air handler power shall be turned off.
  4. Supply boots or registers and return boxes or grilles shall be taped, plugged, or otherwise sealed air tight or as tight as possible.
  5. The hose for measuring the 25 Pascals of pressure differential shall be inserted into the boot of the supply that is nominally closest to the air handler.
  6. Open all interconnecting doors in the building, close dampers for fireplaces and other operable dampers.
  7. Set up an envelope air moving/flow-regulating/flow measurement assembly, such as a blower door, following the manufacturer’s prescribed procedure.
  8. Specific instructions from the duct testing equipment manufacturer shall be followed to reach duct test pressure and measure duct air leakage used in combination with a blower door. Typical steps are as follows:

    1. Depressurize the ductwork system to 25 Pa using the measurement hose in Step 5 above.
    2. Depressurize the house to 25 Pa using an envelope air moving/flow-regulating/flow measurement assembly, such as a blower door.
    3. Correct the duct pressure to measure 0 Pa of pressure differential between the house and the ductwork system.
    4. Read the CFM of duct leakage using the procedures for the specific equipment being used. (Note that most automatically calculating pressure gauges cannot compute the CFM25 automatically with a duct-to-house difference in pressure of 0 Pa, so the gauge setting should be set to read CFM instead of CFM25.)

   Testing shall be performed and reported by the permit holder, a NC licensed general contractor, a NC licensed HVAC contractor, a NC licensed Home Inspector, a registered design professional, a certified BPI Envelope Professional or a certified HERS rater. A single point depressurization, not temperature corrected, test is sufficient to comply with this provision, provided that the duct testing fan assembly(s) has been certified by the manufacturer to be capable of conducting tests in accordance with ASTM E 1554-07.

   The duct leakage information, including duct leakage result, tester name, date, company and contact information, shall be included on the certificate described in Section 401.3.

   For the Test Criteria, the report shall be produced in the following manner: perform the HVAC system air leakage test and record the CFM25. Calculate the total square feet of Conditioned Floor Area (CFA) served by that system. Multiply CFM25 by 100, divide the result by the CFA and record the result. If the result is less than or equal to [4 CFM25/100 SF] the HVAC system air tightness is acceptable.

Complete one duct leakage report for each HVAC system serving the home:

Property Address: ____________________________________________________________________________________

HVAC System Number: _______________ Describe area of home served:____________________________________ CFM25 Total _________. Conditioned Floor Area (CFA) served by system: __________ s.f.

CFM25 x 100 divided by CFA = _______ CFM25/100SF (e.g. 70 CFM25 x 100/2,000 CFA = 3.5 CFM25/100SF)

Fan attachment location: ___________________________________________________

Company Name: _____________________________________________________________________________________

Contact Information: __________________________________________________________________________________

____________________________________________________      ___________________
Signature of Tester                                                                 Date




Permit Holder, NC Licensed General Contractor, NC Licensed HVAC Contractor, NC Licensed Home Inspector, Registered Design Professional, Certified BPI Envelope Professional, or Certified HERS Rater
(circle one)
Resources