Good ductwork in a home is critical because it basically functions as the circulatory system of the house. It makes sure all the heated or cooled air gets to where you want it. You want to make sure that the ducts are as air tight as possible so that the air you are paying to heat or cool gets to where you need it. A duct leakage test is performed to ensure the ductwork of the home is properly sealed so that the heated or cooled air comes out of the registers as intended and does not escape through leaks in the ducts and into wall cavities. I usually perform a duct leakage test prior to drywall installation this way if problems are found they are still easy to correct. Old ductwork disintegrates over time and I sometimes get calls from homeowners suspecting they are losing energy efficiency due to faulty ductwork.
As of 2018 The State Of Pennsylvania requires a blower door test on all new residential units. A duct leakage is test required to be performed if any of the duct or the HVAC system site outside of the building envelope such as in a basement, crawlspace or an attic. These tests are gradually becoming more enforced in Philadelphia and the surrounding areas.
I regularly work with contractors to test the ducts and provide the certification they need to present to the building inspector so they can close out their walls or building permits.
The best way to ensure that the duct leakage test is a success
- Only use high quality duct mastic and duct seal tape
- Make sure to seal all connections and joints
- Make sure to seal the boots as well
- Seal any penetration in the air handler