Air Sealing our Passive House One (Progressively Smaller) Air Leak at a Time
Having established a real baseline with our first blower door and thermal imaging tests, Lisa and I began the arduous task of sealing (plugging) the air leaks one at a time.
To aid us in identifying and eliminating the air-leaks, we constructed our own blower-door out of a conventional box-fan , some left-over vapor barrier material, and tape from our sub-slab basement installation.
Of course we didn't have any measuring equipment attached (like a true blower door would have), but the purpose of our make-shift blower door was to simply generate enough negative pressure to pull the air-leaks through the openings that needed to be sealed.
Fortunately, our air-tightness efforts were conducted during the cold winter months. This made it very easy to feel the cold air rushing in to our heated interior space as the temperature differences were significant at that time. At this phase in our construction, we had no electricity and no drywall installed. As such we resorted to using LP heaters to raise the internal temperatures of the house to upwards of 70F.
An interesting consequence of heating with propane, was the generation of elevated levels of relative humidity. At certain times, we were also able to identify potential problem areas, by spotting areas where condensation was taking place--a tell tale sign of an air leak.
And so it went, hour after hour, day after day, repeatedly locating an air-leak and then sealing the air-leak until we felt we took it as far as we could on our own.