Blower Door

A machine used to test the airtightness of buildings or of smaller spaces within buildings. A blower door is mounted in an opening such as a window or door and then uses a fan to pressurize or depressurize the measured space. The more airtight the space, the less air is needed from the blower door fan to create a change in air pressure.

Related terms: ACH, Air Leakage

Related resources: BSI-053: Just Right and Airtight, BA-0413a: The Snapshot—A Quick Description