A blower door consists of a number of parts used to pressurize or depressurize a house and measure the amount of air that leaks through the home. It is similar to blowing up a balloon and looking for holes in the balloon, except in this case you are pressurizing your house.
An aluminum frame is placed in an exterior door. A vinyl cover is placed over the frame and a fan is inserted into the cover. The fan creates a pressure difference between inside the house and the outside. A pressure gauge called a manometer measures pressure at a location within the fan, and this measured pressure is directly related to a quantity of airflow passing through the fan.
The blower door test can provide a standard measure of the tightness of a home, generally in cubic feet per minute. This number can be used to compare your house to standard recommendations for healthy and energy efficient homes. If a home is too tight, there can be health issues caused by poor air quality. If a home is overly leaky, it will cost a homeowner extra money to heat and cool the building.
Learn about air sealing your home to save energy, cut costs and improve comfort.
