How hard is it to pass a blower door test?

The blower door test takes the guess work out of detecting air leaks in a structure; however, most contractors would like to pass the blower door test the first time. It is estimated that 50% of newly constructed homes will fail the blower door or air-tightness test.

What is a blown door test?

In simple terms, a blower door test is a diagnostic procedure performed by a certified professional to identify air leakage in a building. It simulates observing the home (or building) with a 20 mile per hour wind blowing on it, so wherever air can enter it will.

Are blower door tests required?

The most common use of a blower door test is as a part of code compliance testing in new home construction. Because the air leakage is so important, this test is required by building code. Think of it this way: an air-tight home is a demonstration of a higher quality of construction.

What do blower door test numbers mean?

Every 10 points on the blower door is about 1 square inch of air leak. So a 1400 cfm50 blower door number is about 1 square foot of air leakage across the whole home. That’s not that much to chase, so every little bit counts. (1400/10 = 140 square inches/144 square inches/square foot = 1 square foot)

When should blower door testing be done?

Blower door testing is often done near the end of the building process of a new construction home, when the paint is done, final doors and windows are in place, and the weather stripping is installed.

What is an uncalibrated blower door?

Uncalibrated blower doors can only locate leaks in homes. They provide no method for determining the overall tightness of a building. The calibrated blower door’s data allow the auditor to quantify the amount of air leakage and the effectiveness of any air-sealing job. Take the following steps to prepare your home for a blower door test:

How do blower doors work in auditors?

How They 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.

Why is it important to calibrate a blower door?

It is important that 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.