Blower door disappointment and questions
We had our final blower door test and it wasn't what we had hoped. Our initial cfm50 was 98 with windows and door and all the sheathing done so I expected a substantially better result with insulation and the smart vapor barrier. Our result was 220.
Obviously the higher air leakage has to be from penetrations after the building envelope was finished - vents mostly, I figure.
My questions are - do you tape over the vent covers or the HRV vents for the blower door test? Also, when you calculate volume do you include everything within the thermal envelope? The ceiling joists are insulated with dense packed cellulose. In the 2 upstairs bedrooms, the ceiling is 8 ft, but the storage area above that is not really closed off from the house. Is that considered part of the house volume?
Thank you for your help. I realize that 220 is still a "Pretty Good" result, it's just that I hoped for better.
Posted Aug 14, 2014 8:40 PM ET
Edited Aug 14, 2014 8:47 PM ET
Other Questions in Green building techniques