Blower-Door Testing Basics
Get ready: Airtightness requirements are part of the 2012 building and energy code.
Synopisis: Airtightness will be a watchword in the coming years as the requirements of the 2012 International Residential Code (IRC) are put into practice. Building-science educator, Larry Armanda, gives a detailed account of how airtightness is measured, and the standards that must be adhered to. A blower door has a powerful variable-speed fan and a two-channel digital manometer, or air-pressure gauge. After being temporarily installed in an exterior door opening and turned on, it draws air from the house and blows it outside. The manometer measures both inside and outside air pressure. The idea is to register the difference between the inside and outside air pressure using the blower door’s fan. The amount of air and fan power that it takes to register the difference corresponds to how tight or how leaky the house is.
Air leaks in houses are a big problem. Leaks make homes uncomfortable and expensive to…