I've talked before about the advantages of a whole-house (attic) fan, but I ran into this article last weekend and thought it was worth a reminder for us all. The summary of how a whole-house fan can save money:
Depending upon its size, a whole-house fan uses only 10% to 20% as much electricity as a central air conditioner. Also, it uses significantly less electricity than a window air conditioner, yet it keeps the entire house more comfortable, not just one room. Installing one generally provides a good payback on the investment.
The comfort and saving benefits of using a whole-house fan result from drawing cooler outdoor air throughout your home and the windchill effect of the breeze upon your skin. The indoor breeze from a properly sized whole-house fan can make you feel up to 6 degrees cooler than you would in still air.
We use our attic fan almost every night in the summer. The days are hot (85 degrees or so) but nights are cool (60-65 degrees). So we set the AC to a high temp during the day when we're mostly out and about anyway. Then, before we go to bed at night, we turn on the attic fan to suck the cooler outside air into the house and out through the attic (pushing all the stored hot air from the day out ahead of it.) It's amazing how running the attic fan for only 15 minutes or so can make such a huge difference in the temperature inside the house.
Once the whole-house fan has done all the cooling it can do, we turn it off, shut up the house again, and turn on the AC to keep us cool during the evening.
We've had a whole-house/attic fan in every home we've owned except for one, and we'll certainly have one in our new home (if we ever buy a new place.) It's a great money saver and one "appliance" we've come to really appreciate through the years.
My parents have one, but it is unbelievably loud. If we had one I would be worried about not hearing our young son wake up if it was on. I wonder if newer models of attic fans are quieter? Theirs was from the mid-80s after all.
Posted by: Kevin | August 21, 2008 at 10:33 AM
Kevin --
We just run ours for 15-20 minutes before we all go to bed -- not throughout the night -- and you could do the same. It would certainly save over having your AC do all the work.
They are loud (they have to be powerful enough to suck air all through the house and out again), but I do believe the newer models are quieter than older ones (ours is 20 years old, so it's probably as loud as the one you're talking about.)
Posted by: FMF | August 21, 2008 at 10:39 AM
These are only actually good for cooler regions. Where I live in Texas it's still 80 degrees at night...you can only escape the need for AC for a few months out of the year.
Attic fan: Good for some regions, bad for others.
Posted by: Otis | August 21, 2008 at 10:53 AM
I remember my grandparents had one in their house when I was growing up and swore by it. I've considered this in the year that I've lived in our new house, but I was wondering what the costs were, as well as what it looks like. I would assume it should go in a central hallway, so you don't want something ugly looking, as that could come back to haunt you later.
Posted by: MoneyBeagle | August 21, 2008 at 12:16 PM
FMF, you're in Michigan aren't you? How does having an attic fan work with the winters there? I'd imagine that you wouldn't want a huge heat leak in your attic during the colder months.
Posted by: Richard | August 21, 2008 at 12:19 PM
If you're attic is insulated properly it shouldn't be heated in the winter.
Posted by: MonkeyMonk | August 21, 2008 at 12:36 PM
Richard --
Yes, I'm in Michigan. The fan has slats that cover it from the inside of the house. Inside the attic, it is insulated around the fan so that any air flow from the attic to the home is minimized. Walking under it in the winter I've never felt any sort of cold or draft.
Posted by: FMF | August 21, 2008 at 12:55 PM
We live in a 110 year old two story Victorian. We installed ours in at the top of the foyer stairs when we bought the house 12 years ago. It's right outside our bedroom door.
It is loud, but it works well. We live in Iowa and we've only had the A/C (window unit that cools the downstairs) on twice this summer.
It sits in a frame box that is insulated around the edges. In the winter I cover it with about a foot of fiberglass insulation.
I think it cost about $300 12 years ago to purchase and have installed.
Posted by: rwh | August 21, 2008 at 04:50 PM