The Blower Door Test: Fundamental To Your Home Energy Evaluation

A blower door test should tell you a lot about your home’s hidden energy-wasters: air leaks. The cumulative size of all air leaks in a typical house can add up to as much as 200 square inches – about the same as leaving a window half open 24/7. Through these inconspicuous cracks and gaps, heat energy infiltrates your home in summer and escapes in winter, creating an all-season money drain.

As part of a professional home energy evaluation, blower door technology takes the mystery out of air leakage both by quantifying the extent of the problem and allowing an HVAC technician to pinpoint the leaks. This makes the air-sealing process – usually simple strategic application of weatherstripping and caulking – more effective. Here’s what’s involved in a blower door test:

• A blower door temporarily mounts in the door frame of an exterior door. The unit incorporates a powerful fan and utilizes sensors to measure air pressure in the house and airflow through the fan. This data is fed to a computer programmed with specific information about the home such as total square footage.
• All exterior doors and windows are closed as well as vents, the fireplace flue and any other openings that admit air.
• The blower fan induces negative air pressure by pulling air out of the home. Once a standardized level is attained, airflow through the fan is monitored to determine the volume of air necessary to maintain a consistent level of negative pressure. The software crunches this data into a figure that represents the total amount of air leakage from the home, expressed in square inches.
• While the home is in a depressurized state, the technician can identify the exact location of leaks. Using a smoke pen to detect air currents or a thermographic camera to image infiltrating heat energy, leaks can be pinpointed and marked for subsequent sealing.

Sobieski Services, Inc. offers professional energy evaluation services including a blower door test to diagnose energy losses from your home. Our goal is to help educate our customers in Delaware, Pennsylvania, Maryland and New Jersey about energy and home comfort issues (specific to HVAC & plumbing systems).

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