What Blower Door Tests Really Tell Us About Performance

Energy Use

Course Description

Behind glazing ratio, the air tightness of an enclosure is the second most significant factor influencing energy efficiency.  We get a sense of how air tight a building is by performing a blower door test. “Blower doors” use a large fan to pressurize a building to a set pressure (usually 50 pascals, which is about the pressure induced by a 20 mph wind) and we can then infer how many times all the air in the building would be replaced if we were to hold that pressure constant for an hour.  We often use blower door test results as a proxy for energy efficiency.  This is useful in that it provides us with a standard benchmark and allows us to compare different buildings . But buildings don’t actually operate at 50 pascals!  What is the relationship between blower door test results and in-service performance?  And how might a building’s climate affect our interpretation of the test results?

Course Instructor Christine Williamson

Course Length 12:15

Published 30 Jun 2022

Please note: viewing this course and completing this quiz do not currently count towards AIA CEU credits.


About Building Science Fight Club

Christine Williamson - Assoc. AIA

Building Scientist | Instructor

Christine Williamson has spent her career in building science forensics, discovering why buildings fail and working with owners, architects, and builders to remedy the problems. She is the founder of the Instagram account @BuildingScienceFightClub, an educational project that teaches architects about building science and construction.