In Passive architecture, you really don’t want your buildings to suck. Technically, you want them to lose less than

  • 0.6 air changes per hour when depressurized to 50 Pascals of pressure for the “old” Passive House Standard, or
  • .05cfm of air per square foot of exterior envelope area when pressurized to 50 Pascal.
Jason LaFleur of EcoAchievers, a PHIUS+ and LEED-H trained rater did a preliminary blower door test today along with his laptop and Tectite software, wirelessly connected to the blower door assembly. Cool tools for sure.
the red door of truth
plotting readings
As you can see on the screen, the device sends a scattering of points which it plots on a curve. We were a little surprised that our first reading was over 0.6ACH50 so we did a walk around the house with his thermal imaging camera to look for leaks.
IR image: “cold” temp is about 66F, 35F outside
We didn’t find any at the windows, but found a big one where the ERV exhaust penetration was taped off. Once we taped it off, we tested again and got a much better reading:
129cfm, or .46ACH50
At 129cfm/0.46ACH50, we’re comfortably under the threshold! So big congrats to the team at Evolutionary Home Builders. This reading is likely to get better after drywall goes in, but it’s not something to count on. One of the lessons of Passive building is to have a single dedicated air barrier system that you can see, test, and repair as needed. Additional layers can help, but first test that system.
living room, facing entry and TV built-in
The house is feeling, aside from warm, much more spatially solid with the insulation (that’s blown-in fiberglass, Knauf JetStream, recycled. no formaldehyde). And the late afternoon winter light was very soft in the master bedroom:
One more shot, looking from front sitting room out to the fireplace–can’t wait to see the Elmwood Reclaimed wood mantle, the wood ceiling of the screen porch, and a fire in the grate…
Drywall, cabinetry, doors, siding…exciting month coming up. See you back here soon.