Air-tightness of US dwellings.

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? How Much Energy Does the Air Leakage Loose in this Building Too Tight? Is this Building Too Loose? When Should Mechanical Ventilation be Considered? Tens of thousands of unique fan presswization measurements have been made of U.S. dwellings over the past decade; LBL has recently been collecting available data into its air leakage database containing over 12000 measurements. This report uses that data to determine the leakage characteristics of the U.S. housing stock in terms of region, age, construction type and quality. Results indicate that US dwellings tend to be quite leaky without respect to climate.