How does the attic fan work? And can you use it in the winter?
Koko22611
| Posted in General Questions on
We bought a house early this year in northern Virginia that has a attic whole house fan. It h’s a pulley on it that closes a box on the fan or opens it. we believe that one way makes the air blow in the attic and the other to push the air down into the closet under the stairs to the bottom level of our home. We had it where the air vented to the attic all summer but not sure that we did it correctly. Now it is getting cold and we are using the fireplace and not sure if we should run the fan or not. The fan is attached to a thermostats in order to adjust it.
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Replies
There's no need to run the fan in the winter unless you burned the turkey for Thanksgiving. Whole house fans were designed to help cool a home during those hot and humid days. Today, Building Scientist think they belong in a trash can for many reasons.
See the claims here.... https://www.greenbuildingadvisor.com/blogs/dept/building-science/top-two-reasons-powered-attic-ventilators-are-waste-money
http://www.finehomebuilding.com/toolguide/departments/what-is-the-difference/whole-house-fans-vs-powered-ventilators.aspx
So when we use the fan system in the summer how do we know how to use the pulley? And we don't have the ventilator system.
Are you saying your fan does not exhaust to the outside, that it only moves air around between the attic and living space?
We have the whole-house fan, but ours vents out from the closet under the steps but only when we have the pulley pulled down. If we have the pulley up it pulls the air up I think. But I am confused on when to have the pulley down and when to have it up.
Aleasha,
The whole-house fan should only be used during hot weather, as Richard said.
The box controlled by the rope and pulley is the cover which prevents heat loss during the winter. The box should be lowered all winter long, so that your house stays warm and your energy bills are lower.
Next summer, when it gets hot enough to use the fan again, you can raise the box using the pulley and turn on the fan at night. You should never operate the fan with the box lowered.
The correct way to operate the fan is to turn it on in the late evening or early morning (before breakfast), when outdoor temperatures are cool. Open the windows on the lowest level of your house whenever the fan is operating. Once your house cools down -- say, by 8:00 a.m. -- make sure that you turn the fan off and close your windows. Don't operate the fan during the afternoon or early evening.
For more information, see Fans in the Attic: Do They Help or Do They Hurt?