Monday, September 28, 2009

21st Century Barnraising

For Centuries New Englanders have gathered to help their neighbors raise barns. This past Sunday my wife, Rachel, and I joined a group of our fellow Cantabrigian's in raising the energy efficiency of a neighbor's home.

For over a year the nonprofit Home Energy Efficiency Team (HEET) has organized monthly weatherization parties for buildings here in Cambridge, MA. The hosting home provides the food, local weatherization companies donate insulation, caulk, foam, and other weatherizing essentials, and volunteers provide free labor in exchange for learning how to better insulate their own home.

Each barnraising starts and ends with a "blower door" test to determine how airtight or leaky the building is. I'd heard about blower doors before but I'd never seen one in action. It's essentially an airtight collapsible door with a large fan in the middle of it (see photo). To run a test you jam the blower door into the building's front entrance, shut all other doors and windows, and then fire up the fan which tries to pump additional air into the building. Air flow monitors connected to the fan tell you how much air is being pumped in, which in turn tells you how leaky the building is.