Blower Door Tests are used by energy Auditors to determine a home’s air tightness.

Some reasons for determining a home’s air tightness are:

• Energy consumption will be reduced
• Reduces moisture and condensation
• Uncomfortable drafts are reduced or eliminated
• Improves home’s overall air quality

How They Work

A powerful fan is mounted into the frame of an exterior door. The fan pulls air out of the house, decreasing the air pressure inside. The outside air pressure then flows in through all unsealed cracks, gaps and holes. The auditors may use a special smoke pencil to identify any air leaks. These tests determine the rate in which air is flowing into the building.

Blower doors consists of frames and flexible panels that fit in a doorway, a high-speed fan, a gauge to measure the differences inside and out, and an airflow hose for detecting airflow.

There are two types of blower doors: calibrated and un-calibrated. The most important thing to remember is for an auditor to 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. Un-calibrated blower doors only detect leaks. With un-calibrated doors there is no method for determining the overall tightness of a building.