Prior to functional testing, verify and document the following:

1. Confirm the pressure boundary wall, ceiling, and floor penetrations are sealed.
2. Confirm all gaps around windows and doors are sealed.
3. Confirm all chases are sealed at floor level using a hard cover and the hard cover is sealed.

Step 1: Perform the dwelling unit envelope air leakage procedure as specified by Reference Nonresidential Appendix NA2.3 to verify the dwelling unit ventilation airflow conforms to the requirements of Section 160.2(b)2.

Step 2: Obtain HERS Rater field verification as specified in Reference Nonresidential Appendix NA1.

Prior to functional testing, verify and document the following:

1. Confirm windows and other openings are open to connect the building to the outside.
2. Confirm HVAC dampers are in their normal operating positions (NOP).

Step 1: Measure and record environmental data at the beginning and conclusion of each test including ambient temperature, indoor temperature and barometric pressure.

Step 2: Install static pressure probe in main plenum pointing into airstream induced by the test. If the test fan is on the roof, the static pressure probe will need to be connected to the measurement device at the test site with a tube long enough to make the connection.

Step 3: If the test fan is mounted inside, with the building open to the outside, use the building as reference pressure. If the test fan is located on the roof, use the outside as the reference pressure.

Step 4: Attach the test fan to the duct system

1. For roof top and wall mounted exhaust systems, remove the fan from the curb or opening and seal the test fan to the curb following test equipment manufacturer’s instructions, making sure the dampers are open (NOP).
2. Alternatively, the test fan may be applied to a grille opening on the inside of the building following test equipment manufacturer’s instructions.

Step 5: Temporarily seal the system including:

1. All of the grilles on the system using masking tape and air impermeable sheeting or duck mask made for this application.
2. Air handler access door or panel (do not use permanent sealing material, metal tape is acceptable).
3. For systems with an air handler with supply and return plenums, the entire duct system including the air- handler shall be included in the test.

Step 6: Adjust the test fan speed to maintain 25 Pa or 50 Pa at the static pressure probe location.

Step 7: Record the air flow (CFM) and temperature.

Step 8: Determine the nominal fan airflow using the product specifications of the installed equipment for the design static pressure.

Step 9: Divide the duct leakage flow by the nominal fan flow and convert to a percentage. If the duct leakage flow percentage is equal to or less than the target compliance criterion of 6% leakage the system passes.

The leakage test can be conducted at rough-in or after the grilles or registers are installed. If the leakage test is conduct at rough-in, the spaces between the grille or register boots and the wallboard shall be sealed, and at least one grille or register must be removed to verify proper sealing.

For compliance with the leakage requirements in Section 160.2(b)2Ci, an ATT shall identify a group of up to three central ventilation duct systems in the building from which a sample will be selected for testing.

Prior to functional testing, verify and document the following:

1. Confirm the total design ventilation airflow rate for the dwelling units served by the central ventilation system as required by Section 160.2(b)2Av.
2. Visually confirm that an ERV/HRV is installed and record the make and model.

Step 1: Verify that the ERV/HRV can provide the airflow rate that meets the design ventilation airflow rate by checking its product specifications.

Step 2: Verify that the ERV/HRV’s nominal sensible recovery efficiency is 67 percent or greater, by checking its product specifications or databases such as HVI, AHRI, etc.

Step 3: Verify that the ERV/HRV can meet the fan power requirements of Section 170.2(c), by checking its product specifications or databases such as HVI, AHRI, etc.

Step 4: Verify that the ERV/HRV has a recovery bypass or free cooling function by visual inspection and checking its product specifications. Verify that its recovery bypass or free cooling control capabilities meet the requirements in Section 170.2, Table 170.2-G.

Step 5: Conduct functional testing of the bypass function according to NA7.5.4.