Final Blower Door

With the house completed and buttoned-up it was time for the final blower door test and checklist audit. Over the course of a few hours, my energy consultants checked-out the house from bottom to top.

They started with a blower door test of the structure. After spending countless hours sealing every nook, cranny, and crack I was crossing my fingers for a great result. Within minutes I had my answer- 134 cfm/50 or in other words .49 ACH (Air Changes Per Hour).

This is not only a fantastic result, but indicative of top-notch quality construction. The Passive House Standard, which is arguably the absolute best house you can build, mandates 0.6 ACH or less. Obviously, .49 ACH substantially beats that number!


Next they checked the air flow through each of the bathroom vents. As you may recall, rather than install bathroom exhaust fans, I chose to vent through the HRV. My primary objective here was to recover the heat from the steamy warm bathroom air as well as avoid puncturing another hole in my envelope.

Upon measurement, I handily exceeded the requirement with 35 cfm continuous through the vents.

The next step was to check the incoming and outgoing exhaust rates from the HRV. Unfortunately, since I have not yet balanced the HRV I did quite poorly in this area. The intake was sucking in nearly 110cfm while the exhaust was putting out only 65cfm. This creates an over pressurization situation which is not desirable.