What tool is typically used to check duct leakage?

The duct tester or blower door is an essential tool used for checking duct leakage. This device works by pressurizing or depressurizing the duct system, which allows technicians to measure the amount of air that escapes through leaks and assess the overall integrity of the ductwork. By creating a controlled environment, the duct tester provides accurate readings of how much air is lost, helping HVAC professionals identify areas that require sealing or repair to enhance system efficiency.

While a manometer and pressure gauge can also measure pressure differences within duct systems, they do not provide comprehensive data on duct leakage by themselves. A thermometer is primarily used for measuring temperature and is not designed for assessing air leakage in ducts.