Spray Foam in the Building Envelope >> Blower Door Testing

What is the Blower Door Test and How Does it Help Save Energy?

If you decide that builing your home tight, is the way to build it right, then you may want to consider the use of a blower door test.

The blower door test and equipment apparatus is fairly simple.  It used extensively to determine where leaks are and how leaky a house or building is from an "air tightness" standpoint.  Air leakage through cracks, gaps and holes in a typical house results in the waste of up to 40% of the energy you buy to keep your home warm in winter and cool in summer. 

Tests using the blower door enable the builder/remodeler to assess the “tightness” of a building, eliminating guesswork regarding leakage and air tightness. The test methodology is widely accepted and is used as one of the predictors for “energy efficiency” in homes. It has been used by energy retrofitters for years to measure the success of their air sealing efforts.

Preventive Analysis
Builders who carry out repeated blower door testing on finished houses learn to anticipate where and how air leakage problems are likely to occur and are able to find ways of avoiding them during the construction process. By avoiding air leakage problems in the first place, builders can avoid costly callbacks and increase customer satisfaction with their product.

The safety of ventilation levels for occupants can also be assessed. In addition, the knowledge that builders or remodeler's gain from the frequent use of this testing leads to a better understanding of the dynamics of airflow in buildings, and thus a better understanding of how their buildings actually perform.

The Blower Door System
The system consists of a powerful, variable -speed fan with a speed controller mounted in an adjustable panel that is temporarily fit into an open exterior doorway. A set of pressure gages are used to measure pressure differences generated by the fan. Airflow across a calibrated opening in the fan housing is also measured.

Test procedures are fairly straightforward. Detailed instructions are usually provided by the supplier or manufacturer of the blower door kit. After the necessary procedures to set up the house have been performed, the test itself takes about 10 to 15 minutes to conduct.

ASTM Blower Door Test Method
E1827-96(2002) Standard Test Methods for Determining Airtightness of Buildings Using an Orifice Blower Door