What is a Blower Door?

A Blower Door is a device that fits into a doorway or building, containing a fan, for supplying or extracting a measured rate of air flow. It is normally used for testing air leakage by pressurization or depressurization [1]

[1] M. Limb, “Technical note AIVC 36- Air Infiltration and Ventilation Glossary,” International Energy Agency energy conservation in buildings and community systems programme, 1992.