What’s the range of window air leakage values for good-quality US windows vs. garden-variety vs. Passive House-quality?
It’s very hard to find published window air leakage rates (in cfm/ft2), harder still to get independent test reports with this information. So far I’ve found the following data points:
* a maximum of 0.3 for all of one US mfr’s product line (in an internal manual);
* .02 for a tilt-turn unit by same mfr (from independent test report);
* .003 for a Canadian mfr’s tilt-turn unit (from website literature).
I’ve also been told that the test apparatus doesn’t yield a result smaller than .01.
What’s the real story here? What is a typical value for a US good-quality (i.e., double-pane, low-e, wood or fiberglass) residential window? What is a typical value for an older, single-pane window? What is a typical value for a Passive House-worthy window?