Blower Doors are used to measure the air tightness and air leakage of building envelopes. As existing dwellings in the United States are ventilated primarily through leaks in the building shell (i.e., infiltration) rather than by whole-house mechanical ventilation systems, quantification of airtightness data is critical in order to answer the following kinds of questions: What is the Construction Quality of the Building Envelope? Where are the Air Leakage Pathways? How Tight is the Building? How Much Ventilation Does the Air Leakage Supply?
Now a widely used diagnostic tool, blower doors have revolutionized the way most professionals approach retrofit work. This introduction explains how blower doors work, what can be gained from their use, and what a typical blower door test involves.