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--
Phil Scott
Ideas are bullet proof.
"Lacustral" <lark@adore.lightlink.com> wrote in message
news:e6291q$3j6$1@admiral.lightlink.com...
> I would like to use an exhaust fan (fan from a ceiling grille to
> outside) to
> run overnight in the summer, with the windows open, so that
> my house is cool
> in the morning. I am not sure how much CFM is needed. I
> do not want a big
> powerful whole house fan because I would like it to be quiet.
> Just a small
> fan that keeps running overnight.
>
> If you're using a fan for that purpose, can you tell me how
> much CFM gets
> your house down to the temperature of the outside air, and
> how many cubic
> feet of airspace you're ventilating, and how long does it
> take to cool
> the house down to the outside temperature?
>
> Just trying to get a ballpark idea.
>
> (I could calculate the cubic feet of airspace in my house,
> divide by CFM
> of a fan, and come up with a guess, but I am sure it's not
> that simple -
> the hot stuff in the house is heating up the air, fans
> aren't completely
> efficient about clearing out the inside air, etc.)
One air change an hour would do it... 3 air changes an hour
would do it by midnight.
so if the house is 1500 sq ft with an 8' ceiling the volume is
maybe 12,000 cubic feet...divide by 60 to get CFM for one air
change..thats 200 cfm... a very small fan, you can do a well
by leaving a few windows open... 600 cfm is more like it, most
attic fans will fit that bill. you could mount it on the room
and fit a vent though a hallway ceiling so it pulls the house
air out first, then the attic air cooling both of those
spaces.
Phil Scott
>
> Thanks
> Laura
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Re: fanpower needed to cool house overnight
