Whole house fan

So after 3 years of living in this house with no AC I went and bought a house fan, the 30" belt drive at Home Depot. So I need to stop tomorrow and get some Romex, a metal box for the attic and a breaker. The install it self won't be to bad, and I have a way to get the Romex to the panel in the garage. But I have pizza and beer if anyone wants to supervise that knows more about electrical then me! The upstairs bedrooms stay to hot to sleep in during the summer so I need to get this done soon before it gets even hotter.

I'm an electrician not an HVAC guy but the air flow exhaust thing is important. Got to have the right amount of vent area in attic. CFM should be listed. Not an easy installation to complete. Sorry not near Ault or I would be glad to help.

I can't offer any help but I've been considering an attic fan as well. I have central air but having a multi level house means the lower two levels are like a meat locker in order to keep the upper two levels cool. Not to mention the late afternoon sun beats down on my bedroom windows.

Mind if I ask how much the fan cost?

Besides the attic, do you have a place from there to exhaust the warm air to?

Man I was just thinking about this tonight. We had a whole house fan at the last house and it was awesome.

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Originally Posted by ray1970

I can't offer any help but I've been considering an attic fan as well. I have central air but having a multi level house means the lower two levels are like a meat locker in order to keep the upper two levels cool. Not to mention the late afternoon sun beats down on my bedroom windows.

Mind if I ask how much the fan cost?

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Ray, attic fans & whole house fans are two different creatures.......

Can't offer any install help/advice, unfortunately. We have A/C but we also had a whole house fan installed right after we moved in . . . had them in other houses and they are awesome. Ours is a 36" and it moves a ton of air. I run the fan for 15-30 minutes early morning to get the house nice and cool to start the day and the A/C doesn't have to come on as early. Then when it cools down at night, we open up the windows, turn off the A/C and cool the whole house down again. Amazing how fast it can cool off the 2nd floor--perfect sleeping temps.

I agree with the point about the added ventilation. You're pushing a lot or air into the attic and it has to have a way to get out. When ours was installed they put in about 5 additional, good sized ridge vents.

Thanks, Bob. I didn't know that. We had an attic fan in the house I grew up in. I think that's what I am wanting.

"Attic Fans" are small, usually around 12-16 inch fans that exhaust hot air from your attic to reduce the heat load on your AC and make your roofing shingles last a couple years longer. These (usually) don't require much additional passive ventilation - the existing soffits and gable vents are usually adequate.

"Whole House Fans" are big mothers, 3-5 FEET across. They are designed to cool the entire HOUSE by drawing in cool air from ground level. A WHF can cool your entire house by 15-20 degrees and make it unnecessary to run your AC 95% of the summer. You get fresher air at a fraction of the cost of running AC (around $1 per day vs $10 per day).

The typical ventilation required for running one of these is an entirely open attic door or pull-down stairs. Additionally, you need to open several windows in strategic spots on the lowest level of the house to draw in cool air. If you don't adequately ventilate, you will quickly burn out the motor of the fan. It's an expensive replacement, or even a fire hazard.

Make SURE you have a fully functioning and RIGID guard in front of the fan blades. A couple years ago our neighbors kid (maybe 10 years old?) accidentally put his hand into the spinning blades. Spent 12 hours in microsurgery, over 250 stitches. These things are powerful.

The attic fan we had growing up was huge. Maybe 36-40" or so. The fan was mounted on the outside of the house in the attic. When it came on it would draw air out of the attic. There was a louvered panel in the ceiling in a room in the center of the house. The louvers would open when the fan started drawing air out of the attic and fresh air would come into the house through any open windows.

Quote:

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Originally Posted by ray1970

I can't offer any help but I've been considering an attic fan as well. I have central air but having a multi level house means the lower two levels are like a meat locker in order to keep the upper two levels cool. Not to mention the late afternoon sun beats down on my bedroom windows.

Mind if I ask how much the fan cost?

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Out heat/ac has a 2 stage? system, we keep the fan on (not in Auto mode) during warmer months. It really made a difference last summer. Kept ac in use time down to 1/2 of what is was with the old system

We have a whole house fan, professionally installed. It works awesome, but you MUST have enough vents in your attic to exhaust the volume of air that the fan will move!!! This means cutting holes in the roof and/or gables and adding more vents. This is not optional.

Otherwise the fan will overload the venting and pressurize the attic, greatly reducing the efficiency of the fan and air movement, stressing the fan and motor, and eventually the motor will fail.

We hardly ever run our a/c, only when it's just too damn hot. The fan works great, but if it's 95* outside, it'll be 95* inside too. Works best to open the windows on the shady side of the house and leave the ones on the sunny side closed. It's bitchin' on hot nights though! Makes a great breeze through the bedrooms.

I believe ours was installed when the house was built. 3' and auto-louvered intake. Each end of the attic has large wire mesh and louvered vents in the gable ends in addition to the normal roof vents.

If it's really hot, I can turn on one of the back yard sprinkler circuits for a cycle, open the patio door, and it's like a giant swamp cooler.

Key for us is getting the house cool at night, then shuttering it up lie a tomb. It will stay comfy even on very hot days into the afternoon unless the wife starts opening doors. [Bang]

Granted, I do have a window AC in my office, but I also have lots of gear in here.

Here in the banana belt most folks use evaporative coolers. Cheap to run and very efficient. Yesterday as temps hit the 80's I got ours going for the first time this year. In half an hour the house was 65 and the wife jokingly complained that it was "miserably cold in here".

Love our Breezeair coolers! One of the best investments we've made here. When it hits 100 they can keep the house at 68-70. Self flushing and the pads will go 8 years or more.

Thanks to everyone here who did their part to pay our $1000 in Xcel energy rebates! [Beer]

Im your huckleberry