Blower Door Test

BPI certified professionals use blower door tests during an energy audit to help determine a home’s air-tightness. If a home isn’t air-tight then air leaks are present. Leaks translate to a loss in heated or cooled air. This means higher home heating and cooling bills, as heating and cooling systems have to work overtime. Here are some key reasons to keep a home airtight:

  • Reducing energy consumption due to air leakage.
  • Avoiding uncomfortable drafts.
  • Avoiding moisture condensation problems.
  • Maintaining healthy air quality.
Blower door test during a home energy audit. Credit: Holtkamp Heating & A/C, Inc.

Blower door test during a home energy audit. Credit: Holtkamp Heating & A/C, Inc.

How Do Blower Door Tests Work?

A 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.

*TIP* – When scheduling a blower door test, it is important that the energy auditors use a calibrated door. This type of blower door has several gauges that measure the amount of air pulled out of the house by the fan. Uncalibrated blower doors can only locate leaks in homes. They provide no method for determining the overall tightness of a building. A calibrated blower door allows the auditor to quantify the amount of air leakage and the effectiveness of any air-sealing job.

How To Prepare For A Blower Door Test

Take the following steps to prepare your home for a blower door test:

  • Close windows and open interior doors.
  • Turn down the thermostats on heaters and water heaters.
  • Cover ashes in wood stoves and fireplaces with damp newspapers.
  • Shut fireplace dampers, fireplace doors, and wood stove air intakes.

Once a blower door test is completed, a comprehensive weatherization and energy efficiency plan can be devised to help make your home as energy efficient and comfortable as possible. And don’t forget, if you bought a new home, it’s recommended that you schedule a blower door test. New construction doesn’t guarantee quality work. Be an informed homeowner and live comfortably, while saving money and resources.

Behind the Walls
Innovation Center
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Cambridge, MA 02142