re: solar attic fan question
14 mar 2002
gary tait wrote:
>bill roosa wrote:
>>...i believe that we all have roofs to "keep the water out" so
>>a hole would not even be an option for most of us.
>make a riser, and install a rain cap (much like you do for a chimeny).
or use a ridge vent, or put the hole in the gable.
cfm = 16.6asqrt(hdt), so a = 800cfm/(16.6sqrt(8'x10f)) = 5.4 ft^2
makes 800 cfm with a 10 f temp rise and an 8' height difference.