The purpose of this test procedure is to measure the air leakage rate through a building envelope.

1. This enclosure leakage procedure is applicable to nonresidential buildings.
   1. Buildings that have less than 10,000 ft² of conditioned floor area may perform the whole-building air leakage test in accordance with Residential Energy Services Network (RESNET)/ANSI/ICC3 380-2019 Guidelines and RA3.8 rather than those in NA5.2-7.
   2. Buildings that have more than 50,000 ft² of conditioned floor area, a sectional test method of co-pressurizing representative test floors and taking data from the specific floors is permitted when following the procedures in Sections NA5.2-7. Representative test floors must meet the following conditions as adopted from ASHRAE 90.1-2019 Exceptions to 5.4.3.1.1:
      1. The entire floor area of all stories that have any spaces directly under a roof.
      2. The entire floor area of all stories that have a building entrance or loading dock.
      3. Representative above-grade wall sections of the building totaling at least 25% of the wall area enclosing the remaining conditioned space. Floor areas in parts a) and b) shall not be included in the 25%.
      4. When interpreting the data and determining the final air leakage rate, the measured air leakage is area-weighted by the surface areas of the building envelope.
2. The measurement procedure shall be based on the specifications of ASTM E3158 by blower door fan assembly (architectural only) and multi-point regression testing as further specified in Sections NA5.2, NA5.3, NA5.4, NA5.5, NA5.6, NA5.7 below.

The instrumentation for the enclosure leakage measurements shall conform to the specifications in ASTM E3158.

1. Visually review the building for completion of air barrier components.
2. Meet with electrical and mechanical (or controls) subcontractors to review electrical needs for testing equipment and shutdown/sealing plan for mechanical systems and ductwork.
3. Contractor to provide dedicated electrical service for running of fans during the air leakage testing (minimum of 1 non-GFCI circuit 120V/20A per fan required).
4. Review weather forecasts and verify appropriate test conditions.

1. Seal all intentional penetrations where they penetrate the air barrier (i.e., louvers, vents, etc.).
2. Fill plumbing traps with water. Toilets, sinks, floor drains, waterless urinals must be primed. Airtight caps on drains are acceptable.
3. Shut off the HVAC system – or leave in “pilot” mode (to avoid introducing air movement that is not included in the calculations). Any automated pressure relief dampers must either be disabled, sealed, or set to a pressure well above 75 Pa.
4. Disable combustion equipment or leave in “pilot” position.
5. Seal all intentional openings in building envelope so that they are air-tight. Acceptable sealing materials include but are not limited to carpet protection plastic, adhesive grill mask and tape and plastic (4 mil poly sheeting or thicker). Intentional openings include, but are not limited to, the following:
   1. Supply air intakes
   2. Make-up air and other intakes/louvers
   3. Exhaust ducts/vents/louvers
   4. Plumbing exhausts
   5. Pressure relief dampers or louvers
   6. Fume hoods
   7. Other exhaust vents (kitchen, bathroom, dryer, etc.)
   8. Any other locations where air leakage can occur within the mechanical system during inactive periods
   9. Any other intentional opening in the building envelope other than doors and operable windows
6. Close and lock exterior windows and doors. Close any vents within window frames.
7. Prop interior doors open to create a single uniform zone.
8. Where drop ceilings are installed in a location that constitutes a barrier to air flow between the testing equipment and the plane of air tightness of the space being tested, remove ceiling tiles at a rate of one per 500 ft² to prevent movement of tiles during test and to ensure a uniform pressure within plenum space. Additional tiles can be removed to ensure a uniform pressure distribution in the plenum space.
9. Install exterior electrical box caps (if applicable).

Pressurize the building to 75 Pa to approximate if building is expected to pass test and to confirm that pre-test set up is complete and that temporary sealing stays in place while under pressure.

1. Reference ASTM E3158-18 for Whole Building Air Leakage Testing.
2. Record interior and exterior weather conditions.
3. Record average wind speeds.
4. Record interior and exterior temperatures before the testing begins.
5. Record site elevation in feet above sea level.
6. Measure bias pressures with fans off and covered.
7. Perform a multi-point pressurization test from at least +25 to +50 Pa (leakage is reported at 75 Pa, as attained or extrapolated).
8. Record a minimum of 5 points between minimum and maximum induced pressures.
9. Measure bias pressures at end of multi-point test with fans off and covered.
10. Record interior and exterior temperatures.
11. If the pressure exponent n is less than 0.45 or greater than 1.0 per Section 9.5.1 of ASTM E3158-18, then the pressurization test is invalid and shall be repeated.

1. Reverse direction of fans.
2. Measure bias pressures with fans off and covered.
3. Perform a multi-point depressurization test from at least -25 to -50 Pa (optional).
4. Record a minimum of 5 points between minimum and maximum induced pressures.
5. Measure bias pressures at end of multi-point test with fans off and covered.
6. Record interior and exterior temperatures after the testing is complete.
7. If the pressure exponent n is less than 0.45 or greater than 1.0 per Section 9.5.1 of ASTM 3158-18, then the depressurization test is invalid and shall be repeated.

1. Calculate the building envelope air leakage in accordance with guidelines in ASTM E3158-18 multi-point regression tests or the relevant building envelope area when testing in sections.
2. If the building envelope air leakage rate exceeds 0.4 cfm/ft² but is less than 0.6 cfm/ft², a visual inspection of the air barrier shall be conducted in accordance with NA5.7. Any leaks observed should be sealed where such sealing can be made without destruction of existing building components. An additional report identifying the corrective actions taken to seal air leaks should be submitted to the building owner and code official, and any further requirement to meet the air leakage rate will be waived.
3. If the building envelope air leakage rate exceeds 0.6 cfm/ft², a visual inspection of the air barrier shall be conducted in accordance with NA 5.7, and any leaks noted should be repaired. The building will then be re-tested until either the building envelope air leakage rate less than 0.4 cfm/ft², or the building envelope air leakage rate is in the range of 0.4 cfm/ft² but is less than 0.6 cfm/ft² and a visual inspection and repair program is executed.

Exception to NA5.6 3. Alterations where less than 100% of the wall area is being altered or additions that are an extension of the existing air barrier, if the building is tested in accordance with the procedures for whole building air leakage in NA5 and the tested leakage rate exceeds 0.6 cfm/ft² of building shell area at 75 pa, a Visual Inspection and Diagnostic Evaluation shall been completed in accordance with NA5.7 and all observed leaks shall be sealed where such sealing can be made without destruction of existing building components. An additional report identifying the corrective actions taken to seal air leaks should be submitted to the building owner and code official, and any further requirement to meet the air leakage rate will be waived.

1. Ensure that all temporary seals and covers for intentional openings such as at louvers, exhaust/intake vents, fireplaces, and rooftop units are properly sealed and not damaged or loosened during the construction.
2. Ensure that all plumbing-traps are filled with water.
3. Ensure that all operable windows, trickle-vents, and doors are properly shut and locked.
4. Ensure that all mechanical systems are shut-off and any mechanical dampers set to the closed position.

Diagnostic Evaluation

5. Identify locations with air leakage using infrared thermography or smoke pens in accordance with ASTM E1186-17, while the building is maintained at a minimum 25 Pa pressure (during pressurization) or -25 Pa (during depressurization). The following locations shall be evaluated:

1. The perimeter of windows and doors.
2. Around operable window hardware and door hardware
3. Penetrations through the roof, wall, and floor assemblies along the plane of the intended air-barrier.
4. Electrical outlets located on exterior-facing walls.
5. Lighting and other electrical penetrations through the roof level ceiling.
6. Above- and below-grade vestibules.
7. Stairs leading to unconditioned space.

1. Generate report in accordance with ASTM E3158 reporting instructions.
2. The report shall include information on the tested building envelope area, conditioned floor area, conditioned air-by-volume, stories above grade, and air leakage rates.
3. Results shall be reported at the upper 95 percent confidence interval.

An independent third-party verification shall be conducted in accordance with the following requirements:

1. A design review shall be conducted to verify and document compliance with the requirements Section 140.3(a)9, specifically:
   1. All air barrier components are identified on construction documents
   2. All joints, interconnections, and penetrations of the continuous air barrier components are identified on construction documents
   3. The continuous air barrier extends on all surfaces of the building envelope (walls, roof, and lowest floor).
   4. The continuous air barrier is designed to resist positive and negative pressures from wind, stack effect, and mechanical ventilation.
   5. The compliance documents indicate the intent to verify the continuous air barrier by way of on-site visual inspection.
2. Inspection shall occur during construction when the continuous air barrier is accessible for a visual inspection. The entire continuous air barrier shall be inspected. The third-party entity conducting the verification shall coordinate with the construction team to schedule site visits such that the entire continuous air barrier is verified.
3. Inspection of the continuous air barrier materials and assemblies shall verify the following are installed correctly:
   1. Transitions to adjacent air barrier systems – including but not limited to roof parapet transitions, glazed framing systems to adjacent framed wall assembly transitions, plaza waterproofing to podium transitions, vertical wall to soffit transitions.
   2. Detailing of penetrations through air barrier systems.
   3. Building assemblies used as ducts or plenums.
   4. Contractor internal quality control/quality assurance.