I was reminded recently what a great deal a whole-house fan is when I read the following in the July/August issue of The Family Handyman:
Depending on the severity of your summers, a fan can work as an efficient prechiller before you switch on your AC, or even as your sole source of cooling. Using only a tenth as much power as your AC, a fan bringing in cooler night and/or morning air can lower inside temperatures by 5 degrees (or more) in just a few minutes.
Does everyone know what a whole-house fan is? It's a huge fan that's usually put into the ceiling of an upstairs hallway (or simply a hallway if you have a ranch home) and vents to the outside through the attic. It's very powerful, so before you turn it on you need to open a few windows/doors. Once on, it then sucks massive amounts of air through the window/door openings, through the house, into the attic, and back outside. The cooler outside air then helps to cool the entire house as it works its way through the home. (FYI, you can see what one looks like as well as a picture of how it works on this page.)
We have had whole-house fans in two of our homes (including our current one) and we simply LOVE them. In the spring and fall when it gets hot during the day and cool at night, we run the fan for an hour or so before we go to bed. It cools down the whole house for the rest of the night with no need for an air conditioner.
In the summer, the fan works to clear the very hot air out of the attic and then makes it easier for the air conditioner to cool the house. We "blow it out" for 30 minutes or so every night. Even thought the outside air may still be 75 degrees at 10 pm at night, it's still much cooler than the attic air (which sits right above our bedrooms.) Once the cooler air is piped in a bit, we turn on the AC and it cools down the house with no problem.
I always knew how well a whole-house fan worked based on our personal experience, but I didn't know it only used 1/10 the power of our air conditioner. That's a HUGE money saver!
I would love if our house had a whole-house fan. I am all about saving money where possible. But, I'm not sure how long we will be in this house and I think adding a whole-house fan might not be cost effective for the time being. Maybe for the next house. :)
Posted by: Patrick | June 26, 2007 at 09:10 AM
I grew up with one of these. We called it an attic fan. I'm sad that almost no new houses around here have them. Almost everyone I knew growing up had them. It was so great in the summer to turn this on and have an instant breeze coming through the house. The one we had was very loud, but I know they have quieter models now. I will definitely be putting one of these in when we build a new house.
Posted by: EricTheGeek | June 26, 2007 at 10:26 AM
There is a potential downside to an attic fan though. Since the fan is essentially a hole in your ceiling, during the winter you lose valuable heat through the fan and its louvered covering. Not to mention there is no insulation in the attic directly above the fan itself. It's hard if not impossible to measure the heat loss but it is something to take into account. I considered having one installed when we built our house last year but decided against it in the end. Sometimes I wish I had it, sometimes not. :)
Posted by: Scott | June 26, 2007 at 01:48 PM
I'm sure you can rig up a cover for the attic fan in the winter.
I think FMF lives in Michigan... I feel like, further south, with a dark brick house, the structure absorbs so much heat throughout the day (and continues radiating in inside at night) that no amount of air circulation alone will cool it down.
As for keeping the attic cool (or trying to keep it cool), you can get temperature-activated 120 VAC fans that go inside the gable vents.
Posted by: segfault | June 26, 2007 at 02:10 PM
I've also read that the whole house fan will bring humid air into the house. If you need to use the air conditioner the next day, it will work overtime to remove the humid air before it can start cooling efficiently. As a result, the article recommended against using the whole house fan to bring cool air (but humid) air in at night, if you anticipate using the air conditioner the next day.
Posted by: Paul | June 26, 2007 at 05:11 PM
House fans seems sort of ghetto. If my cooling system is not destroying the enviornment, then it's not really working now is it?
Posted by: Dee | June 29, 2007 at 04:45 PM
Dee --
Ha!
Our cooling system works too -- byut an attic fans helps it along for much less $$$$$$$$$.
Posted by: FMF | June 29, 2007 at 04:49 PM
What about opening a window or two? Having moved back to North America from 4 years in Australia, I can't see why 2/3 of North America even "needs" air conditioning in the first place?
Posted by: urbanmike | June 29, 2007 at 07:49 PM
Wow urbanmike... you need to stop living in a fantasy world! Try Anytown, USA... that's where the heat is.
It's bloody hot wherever you go in the summer (regardless of your Australia trip).
Besides, we North Americaners would shrivel and die without our airconditioning.
Posted by: Jake | July 04, 2007 at 12:54 AM
I remember growing up with one of these in the house. As other's have said, we always called them an attic fan. We didn't have air conditioning the entire time I grew up and we survived just fine. I agree with urbanmike. In many places (not all) across the country, air conditioning is a luxury not a necessity. As for the winter, a little bit of insulation over the fan in the attic would do the trip.
It's true though that most new homes don't have these. That's a shame if you can really save 90% of your cooling costs.
Posted by: Jon | July 05, 2007 at 01:11 PM
OK, OK, I'm getting one. I know they're wonderful because my sister-in-law had one for her huge house, and she never needed the ac - she had plenty of windows all over the house. The only time I'll probably use my ac is when the air is too humid.
Posted by: dePriest | June 29, 2008 at 02:07 PM
I got my whole house fan about 20 years ago in Chicago from the Suburbanfan company in our area.
The fan finally died...i just had it replaced with a Quiet Cool QC4500. the fan is smaller but does the exact same job with less power. Like 75% less power. The best part is the guy who installed my fan 20 years ago is the same guy who removed my old fan and installed my new fan. There should be an award for this kind of thing...i went on line and looked for the best price and even with me having to pay tax I still got a better deal. The fan is cool because it comes with a remote control that allow me to select high or low speed from my chair where I watch TV.
Posted by: Bob | June 07, 2010 at 06:29 PM