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Appendix 3 Sample Worksheets for Residential Air and Duct Leakage Testing

AMENDMENT
This section has been amended at the state or city level.
APPENDIX 3A
Air sealing: Visual inspection option (Section 402.4.2.1)
Sample Worksheet

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 by the builder, permit holder or registered design professional via the certificate in Appendix 1.1.


TABLE 402.4.2
AIR BARRIER INSPECTION
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 be observable by the code official.
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



APPENDIX 3B
Air sealing: Testing option (Section 402.4.2.2)
Sample Worksheet

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. 0.30 CFM50/Square Foot of Surface Area (SFSA) or
  2. Five (5) 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 [0.24 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 [4 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)


APPENDIX 3C
Duct sealing: Duct air leakage test (Section 403.2.2)
Sample Worksheet

403.2.2 Sealing (Mandatory Requirements). 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 of the NC Mechanical Code.

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

1) Total duct leakage. Total duct leakage less than or equal to 6 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 6 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 E1554-07.

    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 [6 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. 100 CFM25 x 100/2,000 CFA = 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)
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