 #76
OmCheeto
Gold Member
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 2,594
Ratios!...
Not sure what you were after with RValue, but Greg is asking about direct air leakage....
What's the ratio of heat loss from Greg's house via:
the lack of insulation
vs
direct air leakage
?
the lack of insulation
vs
direct air leakage
?
We know that Greg has a 3 story house, with one of the stories being at least partially underground, and from a previous post, the upstairs is unheated, so, I'll interpolate his above ground surface area as being 189 m^2. (1000 ft^2 floor area with 8 ft tall walls)
Using your temperature numbers, I calculate that with the fan on, he would be losing 635 watts.
With a nominal Rvalue of 13, his walls and ceiling will be losing 1815 watts.
Since we don't know his actual air leakage rate, nor his aggregate Rvalue, it's difficult for me to recommend a course of action.
Also, since we now know his bathroom fans have "back draft dampers" and he has exterior flaps, I would not recommend adding more flaps.
ps. obligatory graph:
This tells me, that even at 10% of the fans flow rate, it's still losing 1/27th as much energy as the house, itself.
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