The house envelope is super-insulated and super-sealed. In a passive house, the objective is to seal the home envelope so well that heat energy created by the sun, wood stoves or the back up electrical heaters stays in the house (as long as possible) because there are so few air exchanges or leaks.
The blower door test helps you measure how well your builder/team sealed the envelope: “With a blower door, builders can quantify airflow and the resulting heat
(or cooling) loss, pinpoint specific leaks, and determine when a home needs additional mechanical ventilation.” Energy conservatory has a good article on the testing process.
Rob Gawreletz from Alberta Eco-Visors came the other day to do the blower door test.
After an initial first reading, Rob depressurized the house so that outside air would try to enter the envelope. Then we walked around and identified a few spots where there were minor leaks around doors and windows that had not yet been caulked for painting etc. We noticed that the plumbing stack, which wasn’t hooked up yet, was not closed off. Oops. And we felt some leaks around where the HRV intake pipe entered the box. Both were easy to fix with duct tape.
The test is helpful. You can correct any minor leaks right away with acoustical sealant or other types of sealants in finished areas.
I’m really glad we went with the spray foam on rim joists and the blown in cellulose walls too. They are sealed nicely.
The results were good: .63 ACH (after we sealed the obvious pipes) – .84 ACH before). Congratulations to Doug the builder and the crew. Excellent job.
An average home today is 1.5 ACH or higher. The net zero homes in the city are at about .7 ACH or so after much hard work. . . so we are in the ballpark.
Doug Hyde (DC Hyde Construction, Athabasca) and his team were meticulous and deserve all the credit. Doug told me that he was trained to always take much care when sealing his homes. But this was the first time in his long career that he ever had one of his buildings assessed with the blower door test. Now that he saw the few small errors and fixes, he is looking forward to the next home and next test. And that’s how your good builders become even greener.
I hope Doug becomes an ambassador of the blower door test for other consumers and other builders up north, where winter is long and cold. If there were more grants to reward smarter building standards, as there are in other countries and provinces like British Columbia, then Alberta would be further ahead.