Specifications

2008 Residential Appendices RA3-6
Appendix RA3 – Residential Field Verification and Diagnostic Test Protocols
The duct leakage measurement at rough-in construction stage shall be performed using a fan pressurization
device. The duct leakage shall be determined by pressurizing both the supply and return ducts to 25 Pa. The
following procedure (either RA3.1.4.3.2.1 or RA3.1.4.3.2.2) shall be used:
RA3.1.4.3.2.1 Duc
ts with the Air Handling Unit Installed and Connected:
For total leakage:
1. Verify that supply and return plenums and all the connectors, transition pieces and duct boots have been
installed. If a platform or other building cavity is used to house the air distribution system, it shall contain a
duct, and all return connectors and transition parts shall be installed and sealed. The platform, duct and
connectors shall be included in the total leakage test. All joints shall be inspected to ensure that no cloth
backed rubber adhesive duct tape is used.
2. Seal all the supply duct boots and return boxes except for one return duct box.
3. Attach the fan flowmeter device at the unsealed duct box.
4. Insert a static pressure probe at one of the sealed supply duct boots.
5. Adjust the fan flowmeter to maintain a plus 25 Pa (0.1 inches water) pressure in the duct system with
respect to the outside or with respect to the building space with the entry door open to the outside.
6. Record the flow through the flowmeter; this is the leakage flow at 25 Pa.
7. Divide the leakage flow by the total fan flow determined by the procedure in Section RA3.1.4.2 and convert
to a percentage. If the leakage flow percentage is less than the criteria from Table RA3.1-2 the system
pas
ses.
RA3.1.4.3.2.2 Ducts with
Air Handling Unit Not Yet Installed:
For total leakage:
1. Verify that all the connectors, transition pieces and duct boots have been installed. If a platform or other
building cavity is used to house the air distribution system, it must contain a duct, and all return connectors
and transition parts shall be installed and sealed. The platform, duct and connectors shall be included in
the total leakage test.
2. Use a duct connector to connect the supply and/or return duct box to the fan flowmeter. Supply and return
leaks may be tested separately.
3. Seal all the supply duct boots and/or return boxes except for one supply or return duct box.
4. Attach the fan flowmeter device at the unsealed duct box.
5. Insert a static pressure probe at one of the sealed supply duct boots.
6. Adjust the fan flowmeter to produce a plus 25 Pa (0.1 inches water) pressure at the supply plenum with
respect to the outside or with respect to the building space with the entry door open to the outside.
7. Record the flow through the flowmeter; this is the leakage flow at 25 Pa.
8. If the supply and return ducts are tested separately, repeat items 4 through 6 with the flow meter attached
to the unsealed return box and the static pressure probe in the return plenum, then add the two leakage
rates together to get a total leakage flow.
9. Divide the leakage flow by the total fan flow determined by the procedure in Section RA3.1.4.2 and convert
to a percentage. If the leakage flow percentage is less than the criteria from Table RA3.1-2 the system
pas
ses.
RA3.1.4.3.3 Installer Visual Inspectio
n at Final Construction Stage
After installing the interior finishing wall and verifying that one of the above rough-in tests was completed, the
following procedure shall be used:
1. Remove at least one supply and one return register, and verify that the spaces between the register boot
and the interior finishing wall are properly sealed.