There has been a whole house fan between the second floor and attic of my house for some time. We usually have it on with the downstairs windows open. I just had a thought: Should there be an open outlet/vent to outside when the fan is on? Can I get a remote opening one, so I don't have to go all the way up there when I turn it on? It does pull very strongly as it is, but would adding a vent cause a notable difference?

  • 2
    Normally, a whole-house fan should be ducted to exhaust to outside the house. On the other hand, normally a non-living-space attic should have vents to outside that are open all year, so if you are going to exhaust to the attic I'm not sure your assumption that there isn't a vent is correct.
    – keshlam
    Commented Jul 24, 2014 at 4:18
  • I don't agree with the first assertion - the vast majority of whole house fans, including the one I live with now (not installed by me) vent to the attic. The second I agree with - the attic should have fixed venting. When the whole-house fan is operating into the attic, it increases attic ventilation. Bathroom vent fans and dryer vents should exhaust to the outside, not the attic - but a whole house fan is moving a much larger amount of air, with a lot less (average) moisture in it, and is generally only used in hot weather when moisture condensing in the attic is highly unlikely.
    – Ecnerwal
    Commented Jul 24, 2014 at 13:08

1 Answer 1


The concept of a whole house fan is two fold. One is to bring in the cool evening air, the second is to flush out the hot air that is trapped in the attic. Your attic should already be vented enough to allow the incoming air a place to push the hot air out. If you where to make an opening for the fan to vent it, the cool air will just travel straight to it and not cool the attic as well.

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