Image sourced from: https://scotthomeinspection.com/blower-door-testing/
by Ashland resident and ACC Board Member Candace Turtle
Last month, Ben Scott, ACC’s volunteer energy expert, conducted a blower door (or air leakage) test at my home. This process exaggerates air leakage into the home, then measures and quantifies the air leakage rate. Ben sealed the front door and installed a large fan calibrated with a manometer that measures air pressure & air flow. We turned off the HVAC system, opened interior doors, and then Ben turned on the fan to depressurize the house.
My leaky old house didn’t score very well. We found many leaks by simply feeling for drafts around likely culprits: windows and doors, light fixtures, attic access, plumbing lines, air intakes, and vents. Others were less obvious — visible only with an infrared camera or with the manometer. While the blower-door equipment isn’t strictly necessary, this process does make it easier to pinpoint problem areas. Air-leakage tests like these typically cost $250 to $450, and come with an energy audit. Making this upfront investment can help you prioritize your time and money to reap the biggest energy savings down the line.
One of the more unexpected findings from my test is that many of the outlets on my exterior walls act as “inlets.” That is, lots of hot air was rushing in. Ben suggested I seal the outlets by removing the covers and caulking around them, and/or adding inexpensive insulating gaskets to outlets,available at hardware stores. (This video shows how to make these improvements licketty split.) Other sources of air leakage: My electric panel (fuse box) and old bathroom exhaust vents, to name only two.
Using an infrared camera, which shows surface temperatures, Ben also found unexpected hot air seeping in around the edges of my window frames, a window seat, and even my staircase. Ben suggested using the expanding spray foam for big gaps and caulk for small ones.
I also asked for a bid from AA Insulation to air seal all accessible leakage sites they can, and then blow more insulation into my attic. I may get a city rebate for this improvement. And the next time I get my house painted I’ll make sure the painters caulk all the seams and wall penetrations outside — yet another way air seeps in.
Lastly, Ben noted that I had gaps between my foundation and home where air was leaking in and out. More foam to the rescue. Thanks Ben! I’m hoping all this weatherization work pays off in the winter with a snug house — and less smoke intrusion during the summer.
Cheers,
Candace
Candace Turtle is a member of the board of Ashland Climate Collaborative. She’ll share details about her journey to electrify and weatherize the Historic Nelson House from time to time.