The Blower Door Test


The blower door test evaluates the home’s air sealing, that is, its air leaks, and the heating and cooling losses associated to them. Blower door tests also assess the home’s ventilation.

Blower door tests can detect hidden leaks (bypasses), otherwise difficult to detect. They are used to audit both the energy efficiency of existing and new houses (as part of energy efficiency control and energy rating home programs).

Alternatives To Blower Door Tests

You can perform very simple tests to detect air leaks around your doors, windows and its frames, but since some air leaks are difficult to identify and to measure, the Blower Door Test is a common piece of any professional audit.

A Special Fan

The Blower Test Door is a relatively simple and easy to implement test, usually performed in less than an a hour. It uses a large and special variable-speed fan mounted on a panel that is temporarily fitted into an exterior door opening (doorway).

When the blower door test fan is turned on, the pressure inside your home is gradually reduced, causing the outside air to flow intensely into the house – through eventual cracks and unsealed openings – making it easy to measure and identify those air leaks – a task accomplished by several pressure gauges intertwined with the test fan (they measure both the rate of airflow and the home’s resistance to air infiltration).

Preparing Your Home For A Blower Door Test

Blower door tests demand some basic preliminary steps. You will have to close the windows and open the interior doors, and turn down heaters and thermostats, shut fireplace doors, dampers, and wood stoves and similar air intakes.

Blower Door Tests And Thermographic Inspections

Blower test doors are commonly used with thermographic inspections. The blower door promotes air leaking through gaps and air leaks in the house structures, which will appear as visible black streaks in the viewfinder of the infrared cameras (used to test the insulation).


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