I don't know your layout. I usually call these attic fans because they
are usually in the attic sucking interior air out. I would install two
of these for my application, and the motor is not at the opening
further reducing noise.
Mine is in the ceiling of the second floor hallway between bedrooms.
It's the kind that has louvers on the bottom that open when the fan is
Besides sucking air from the living area, it also ventilates the attic
above and I have used it many times in the summer when I had to go into
the attic to search for something, or do repairs, or make alterations.
It is a lot cooler in the attic than if I went up there without using
Don't go for one of those generic fans they usually use. I have
installed two. The last one I was able to install a green plug to slow
nit down so it was fairly quiet. The current one I only use to flush
the house. I have also been known to turn the fan on high and use a
motorized blower to clean the house. Do you like the sound of an
airplane engine? That's what the fan sounds like.
Go with a lower cfm Panasonic fan. They should do the job. I think
they have a 400 cfm or thereabouts. Check noise levels of specified
I measured the dB in the hallway with my slightly reduced speed fan.
85 dB. Typical bath fans are 100 cfm. My attic fan is probably rated
about 3000 cfm. True, I need more than 100 cfm for the bath, but I up
the cfm by using a bigger online fan which is installed in the attic.
That's the only way to get a nice quiet system by moving the fan away
from the port.
My understanding the whole house fan is not run continuesly. It is
turned on for some time late at night when outside temperature is cool
so together with opening windows downstairs it sucks warm inside air
out and sucks cool air in. After that it is turned off. So the noise
level is not of such a great importance.
I installed one in our first house (no AC). In hot weather I'd leave it
running from sun-down to when we got up in the morning. On really hot days
we'd turn it back on after the house got hot enough to open back up (to keep
the attic "cool"). It was fairly loud but at a rather low frequency so wasn't
obnoxious, like a bathroom fan.
We had one of those when I was in JHS and HS. It seems to me it is
only useful after the outside has cooled off, and that can be pretty
late 8 PM to 1AM on a hot day, depending on how hot the day was and
other things.. Otherwise, when you turn the fan on it draws hot air
from the outside through the open windows making the house warm or
hot, maybe hotter than it was.
If you ran the AC during the day, it sucks all the cool air out of
your house, replacing it with hot outside air.
It probably does cool off the attic, but you dont' care aobut that, do
I have a roof fan (though a gable fan would do the same thing). It
goes on maybe between 10 and noon, and blows the hot air out of the
attic, replacing it with outdoor air, which won't be as hot usually.
It turns off betweem 5 and 8 Pm, or 4 and 9, when the attic cools off
to some preset but adjustable temp.
It keeps the attic as cool as possible which lowers the amount of heat
ing the atttic which can go through the insulation in the floor of
the attic to the occupied floor below. Maybe it's possible to have
enough insulation that no heat makes it from the attic to the floor
below, but i'm not there yet.
I guess the ideal would be to have both or an either/or option. Could be
done with dampers. Cooling the attic space helps with keeping the heat down
so the AC runs less.
On days you don't need AC, but want to cool the attic and suck the heat from
the oven out of the kitchen, or otherwise change the house air quickly, a
whole house fan is ideal. Fans don't remove humidity either.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.