Duct leakage testing — $250
WHAT IS A DUCT LEAKAGE TEST:
A duct leakage test (a.k.a. duct blast) is a test that determines the amount of air leakage through HVAC ducts. A blower fan pressurizes or depressurizes the duct system. A duct leakage test can be performed at rough-in before drywall is hung, or at post-construction. Careful air sealing measures using duct mastic and HVAC foil tapes on all joints, branches, elbows etc., is needed in order pass a duct blast test. Performing the test during rough-in is highly recommended as leakage areas are more easily addressed at this time.
Denver: With the adoption of the 2018 IRC, all ducts in new construction are required to be tested for air leakage:
2019 Denver Building And Fire Code — Duct Testing Amendments:
R403.3.3 Duct testing (Mandatory). The duct work in a building or dwelling unit shall be pressure tested in accordance with ANSI/RESNET/ICC 380 or ASTM E1554 for air leakage. The maximum total leakage rate for duct in any building or dwelling unit under any compliance path shall not exceed 6.0 cubic feet per minute per 100 square feet of conditioned floor area served, (6cfm/100sqft), when the air handler is installed at the time of the test. When the air handler is not installed at the time of the test, the total leakage shall be less than or equal to 3.0 cubic feet per minute per 100 square feet of conditioned floor area; (3 cfm/100 sq ft). Registers shall be taped or otherwise sealed during the test. Testing shall be conducted at the rough‐in stage or post‐construction by one of the following methods:
- Rough‐in test: Total leakage shall be measured with a pressure differential of 0.1 inch w.g. (25 Pa) across the system, including the manufacturer’s air handler enclosure if installed at the time of the test. Registers shall be taped or otherwise sealed during the test.
- Post Construction test: Total leakage shall be measured with a pressure differential of 0.1 inch w.g. (25 Pa) across the entire system, including the manufacturer’s air handler enclosure. Alternatively, a duct leakage test to outside conditioned space with a pressure differential of 0.1 inch w.g. (25 Pa) with reference to the outside across the entire system including the manufacturers’ air handler may be performed. Registers shall be taped or otherwise sealed during the test.
- A duct air‐leakage test shall not be required for ducts serving ventilation systems that are not integrated with ducts serving heating or cooling systems.
- If the HVAC duct system is serving less than or equal to 1,200 square feet of conditioned floor area, the allowable duct leakage shall be 72 cubic feet per minute or less.
Other Counties & 2015 IRC Code Requirements:
For 2015 IRC code requirements and other counties outside of Denver, duct leakage testing is only required for ducts with runs through unconditioned spaces, like attics and crawlspaces. To pass, ducts need to have less than 4% leakage of total square footage.
WHAT WE DO IF YOU DO NOT PASS
If you are unable to pass your duct leakage test, we use a theatrical smoke machine to determine where you are having air leakage issues in order that you can address them. The blower fan pushes the smoke through any leakage area so we can see where they are located. We will continue to work with you until you are able to pass your blower door test. Additional testing is $250 each, including 1.5 hours of diagnostics; additional diagnostics time is charged at $25 per 15 minutes.