Blower Door Testing – Measuring Conditioned Volume of a House
d_buzz
| Posted in General Questions on
Kind of a curiosity question – when measuring the conditioned volume of a home, what are the consensus rules? Do you measure ceiling height nominally (ie 8/9/10 ft) or actually? Include the exterior walls in the SF of floor area (which is typically done when defining house SF for realtor/appraisal/etc.) or measure from interior? What about the cavity b/w floors, and again, nominal measurements or actual?
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There isn't exactly a consensus. Some certification bodies define the criteria (PHIUS and Passivhaus are a couple of examples), so you can use one of those definitions. I think it's generally agreed that only conditioned space counts, but there are some exclusions such as the cavity below floors. Exterior walls don't count. You would use actual ceiling height, not nominal, though in most cases it won't be much different.
This was asked fairly recently, and there wasn't much of a consensus then either:
https://www.greenbuildingadvisor.com/question/ach50-house-volume-floor-to-ceiling-or-floor-to-floor
Thank you, Trevor - I don't know why I overlooked that in the search results from before posting my message and appreciate the guidance to that discussion. Good to know the confusion is not mine alone.