Blower Door Test

To perform a thorough energy efficiency analysis of your home, energy advisors use specially designed "blower door" test equipment to measure your home's rate of air leakage.

The blower door is a variable-speed fan mounted on an adjustable panel that can fit into any exterior door opening of your home. Here’s how the test is run:

1. Reduce house pressure. When the fan is turned on, the pressure inside your home is gradually reduced to allow outside air to flow into the house through unsealed openings or cracks in the house structure.
2. Measure airflow rate. Pressure gauges connected to the fan measure the rate of airflow required to keep your home at a constant pressure so that the advisor can calculate your home's resistance to air infiltration.
3. Calculate energy efficiency. The results of the test are incorporated into your home's energy efficiency rating. Because airtight homes are energy efficient, a house that has little air leakage will result in a higher rating than a home that has a lot of air leakage.
4. Check ventilation. Advisors also ensure that the home is adequately ventilated as part of their analysis because modern airtight homes must always be adequately ventilated, usually with mechanical ventilation.

As part of the EnerGuide for New Houses service, the blower door test is performed after the house has been built so that the "as built" results of the test are incorporated into the rating and the new house label.