Specifications

2008 Residential Appendices RA3-8
Appendix RA3 – Residential Field Verification and Diagnostic Test Protocols
For altered existing duct systems that do not pass any of the Total Leakage (RA3.1.4.3.1), Leakage to Outside
(RA3.1.4.3.3) or Leakage Improvement (RA3.1.4.3.4) tests, the objective of this test is to show that all
accessible leaks are sealed. The following procedure shall be used:
1. At a minimum, complete the procedure in RA3.1.4.3.1 to measure the leakage before commencing duct
sealing.
2. Seal all accessible ducts.
3. After sealing is complete use the same procedure to measure the leakage after duct sealing.
4. Complete the Smoke Test as specified in RA3.1.4.3.7.
5. Complete the Visual Inspection as specified in RA3.1.4.3.8.
6. Install the required label on the system stating that the system fails the leakage tests.
RA3.1.4.3.7 Smoke-Te
st of Accessible-Duct Sealing
For altered existing ducts that fail the leakage tests, the objective of the smoke test is to confirm that all
accessible leaks have been sealed. The following procedure shall be used:
1. Inject either theatrical or other non-toxic smoke into a fan pressurization device that is maintaining a duct
pressure difference of 25 Pa relative to the duct surroundings, with all grilles and registers in the duct
system sealed.
2. Visually inspect all accessible portions of the duct system during smoke injection.
3. The system shall pass the test if one of the following conditions is met:
i. No visible smoke exits the accessible portions of the duct system.
ii. Smoke only emanates from the furnace cabinet which is gasketed and sealed by the manufacturer and
no visible smoke exits from the accessible portions of the duct system.
RA3.1.4.3.8 Visual Inspection of
Accessible Duct Sealing
For altered existing ducts that fail the leakage tests, the objective of this inspection in conjunction with the
smoke test (RA3.1.4.3.7) is to confirm that all accessible leaks have been sealed. Visually inspect to verify that
the following locations have been sealed:
1. Connections to plenums and other connections to the forced air unit
2. Refrigerant line and other penetrations into the forced air unit
3. Air handler door panel (do not use permanent sealing material, metal tape is acceptable)
4. Register boots sealed to surrounding material
5. Connections between lengths of duct, as well as connections to takeoffs, wyes, tees, and splitter boxes.
RA3.1.4.3.9 Verified Low
Leakage Ducts in Conditioned Space
When ducts are located in conditioned space, additional credit is available for Low Leakage Ducts, if duct
leakage to outside equal to or less than 25 cfm when measured in accordance with Section RA3.1.4.3.4. The
home must also be qualified to receive the credit for verified ducts in conditioned space. The ACM credit for
Low Leakage Ducts in Conditioned Space is shown on Table R3-34 of the Residential ACM.
RA3.1.4.3.10 Verified Low
Leakage Air Handler with Sealed and Tested Duct System
An additional credit is available for verified low leakage ducts if a Low Leakage Air Handler is installed The low
leakage air handler cabinet (furnace or heat pump fan and inside coil) must be certified to the Commission to
leak 2 percent or less of its nominal air conditioning cfm delivered when pressurized to 1-inch water gauge with
all present air inlets, air outlets, and condensate drain port(s) sealed. The air handler must be connected to a
Sealed and Tested New Duct System to receive the credit.
The ACM allows the duct efficiency calculation to use the actual measured duct leakage if it is equal to or less
than 6 percent of airflow.