Professional energy auditors use blower door tests to help determine a home’s air tightness.

Here are some reasons for establishing the proper building tightness:

• Reducing energy consumption due to air leakage
• Avoiding moisture condensation problems
• Avoiding uncomfortable drafts caused by cold air leaking in from the outdoors
• Making sure that the home’s air quality is not too contaminated by indoor air  pollution

How They Work

Blower Door Test for the homeA blower door is a powerful fan that mounts into the frame of an exterior door. The fan pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows in through all unsealed cracks and openings.

The auditors may use a smoke pencil to detect air leaks. These tests determine the air infiltration rate of a building.

Blower doors consist of a frame and flexible panel that fit in a doorway, a variable-speed fan, a pressure gauge to measure the pressure differences inside and outside the home, and an airflow manometer and hoses for measuring airflow.