The Build Doctor's team performing a Duct Blaster test at a job site

This diagnostic test combines a small fan and a pressure gauge to pressurize the HVAC duct system while temporarily sealing all heat and AC vents. The Duct Blaster accurately measures the air leakage of the duct system. Duct leakage can increase heating and cooling costs. The U.S. Department of Energy (DOE) reports that most U.S. homes have over 30% leakage, which contributes to health, safety, and comfort issues as well as wasted energy. There are further tests that can be performed to determine the location of the leaks and if the duct system can be patched with mastic (never duct tape) or if the entire system needs to be replaced. The focus on duct leakage is to test HVAC ducts that are outside of the building envelope. Leaky ducts in attics and crawlspaces have a great effect on energy loss, poor indoor air quality, and comfort issues.