Specifications

2008 Residential Appendices RA3-5
Appendix RA3 – Residential Field Verification and Diagnostic Test Protocols
Table RA3.1-2 Duct Leakage Tests
Case User and Application Leakage criteria, % of total fan flow Procedure
Sealed and tested new duct systems Installer Testing at Final
HERS Rater Testing
6% RA3.1.4.3.1
Installer Testing at Rough- in, Air
Handling Unit Installed
6%
Installer Inspection at Final
RA3.1.4.3.2
RA3.1.4.3.2.1
Installer Testing at Rough-in, Air
Handling Unit Not Installed
4%
Installer Inspection at Final
RA3.1.4.3.2
RA3.1.4.3.2.2
Ducts in conditioned space Installer Testing
HERS Rater Testing
25 CFM Leakage to Outside RA3.1.4.3.9
Sealed and tested altered existing duct
systems
Installer Testing
HERS Rater Testing
15% Total Duct Leakage RA3.1.4.3.1
Installer Testing
HERS Rater Testing
10% Leakage to Outside RA3.1.4.3.4
Installer Testing and Inspection
HERS Rater Testing and
Verification
60% Reduction in Leakage and
Inspection and Smoke Test
RA3.1.4.3.5
RA3.1.4.3.6,
RA3.1.4.3.7
Installer Testing and Inspection
HERS Rater Testing and
Verification
Fails Leakage Test but All Accessible
Ducts are Sealed
Inspection and Smoke Test with
100% Verification
RA3.1.4.3. 6
RA3.1.4.3. 7,
RA3.1.4.3. 8
RA3.1.4.3.1 Diagno
stic Duct Leakage from Fan Pressurization of Ducts
The objective of this procedure is for an installer to determine or a rater to verify the total leakage of a new or
altered duct system. The total duct leakage shall be determined by pressurizing the entire duct system to plus
25 Pa with respect to outside. The following procedure shall be used for the fan pressurization tests:
1. Verify that the air handler, supply and return plenums and all the connectors, transition pieces, duct boots
and registers are installed. The entire duct system shall be included in the total leakage test.
2. For newly installed or altered ducts, verify that cloth backed rubber adhesive duct tape has not been used
and if a platform or other building cavity used to house the air distribution system has been newly installed
or altered, it contains a duct or is ducted with duct board or sheet metal.
3. Seal all the supply and return registers except for one return register or the system fan access.
4. Attach the fan flowmeter device to the duct system at the unsealed register or access door.
5. Install a static pressure probe at a supply register or the supply plenum.
6. Adjust the fan flowmeter to produce a plus 25 Pa(0.1 inches water) pressure at the supply register or 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. 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 flows percentage is less than the criteria from Table RA3.1-2 the system
pas
ses.
RA3.1.4.3.2 Diagno
stic Duct Leakage at Rough-in Construction Stage
Installers may determine duct leakage in new construction by using diagnostic measurements at the rough-in
building construction stage prior to installation of the interior finishing. When using this measurement
technique, the installer shall complete additional inspection (as described in section RA3.1.4.3.2.3) of duct
integrity after the finishing wall has been installed. In addition, after the finishing wall is installed, spaces
between the register boots and the wallboard shall be sealed. Cloth backed rubber adhesive duct tapes shall
not be used to seal the space between the register boot and the wall board.