As winter closes in, work continues on this Passive House project. The Intus triple glazed doors and tilt-turn windows are due to be delivered next week. When they are installed, we can perform a preliminary blower door test, to see how close we are to the mythic air tightness requirement of 0.6 ACH.
In the mean time, the duct system has already been installed, with dual distribution systems for tempered air, and for fresh air supply and exhaust. As soon as the building is closed in, other rough-in work will continue.
TESTING FOR AIR TIGHTNESS
AJ Soriano of Elysian Energy records blower door output. We came in at about .75 ACH @ 50PA–four times better than the IRC maximum, but still slightly higher than the PHIUS requirement.
With most of the rough mechanical, electrical, and plumbing work (MEP) complete, it was time to test the Grant Residence Passive House for air tightness.
We scored approximately 0.75 air changes per hour (ACH) at 50 pascals (PA) of pressure. Although this is four times tighter than the current energy code requires–it’s not good enough for Passive House, which requires a reading no greater than 0.60 ACH@50PA. So we still have some tightening up to do.
The bad news is that the testing did not reveal any major leaks. That means mitigating that last little bit will be extremely difficult.
On top of that challenge, the items yet to be installed–the drier vent and the fireplace flue–are inherently leaky.
Using a smoke pencil, DJ searches for visible leaks. Unfortunately, he found very few–which will make additional tightening up very difficult.