Duct leakage testing — $300*. With the adoption of the 2018 IRC, ALL ducts in new construction in the Denver Metro area will be required to be tested for air leakage:
2018 IRC Code Requirements:
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:
In order to pass the test, it is important to apply rigorous air sealing measures using duct mastic and aluminum foil tapes on all joints, branches, elbows etc. During the test, a blower fan will pressurize the duct system and a total air leakage number will be displayed. A duct leakage test can be performed at rough-in before drywall is hung, or at post-construction. Performing the test during rough-in is highly recommended so any problem areas can be addressed.
A certificate will be issued upon completion to present to the city inspector.
2015 IRC Code Requirements:
For 2015 IRC code requirements, testing ducts is a requirement for all ducts that have runs through unconditioned spaces such as attics and crawlspaces. In order to pass the test, ducts can not have more then 4% leakage of total sq footage. For example, a 2000 sq foot home is allowed 80 CFM (cubic feet per minute) of air leakage per the 2015 IRC Energy Code.
* $300 per system. $150 each additional system.