Whole House Fan?

Anyone have one? Likes? Dislikes? I should have’s? Been looking at these for a while, plan to install one in the next couple weeks. Thanks. CZ

What is it? Anything like leaving your furnace fan continuouly on?

Basically a large fan, say in the 5000-7000 CFM anywhere from 24″ up to 48″ depending on your needs. Mounts between the living space into the attic, pulls air out of the house into the attic creating a vacuum in the house. Idea is to exchange outside air via open windows to cool the house down. I’ve always looked at the outside air temp during the summer and the inside air temp and shook my head, esp when we get home from work in the evenings. Also dislike the AC bill.

ahhh. Another option would be to open your windows then strike up a conversation with BrianK nearby…

Leave the AC on there’s going to be a lot of hot air blowing around

Better striking a conversation when he is around than striking a match if you get my drift.

I have one in our ranch house.

The good: Cools the house off very fast and keeps the attic cool also. Cheap to run compared to AC only a fan motor running.

The bad: Can be noisy and needs to be centrally located for best overall air flow. Only works well when the outside air is cool and not humid which in this part of the country is a fair amount of time in the evenings.

I did build an insulated box around mine and made a door that hinged on one side. From the door I ran a rope through pulleys out to my garage so that I can open and close the box without having to go into the attic. The box is insulated on the inside. We also had the exterior walls, tops of interior walls in the attic, and joist pockets filled with spray foam insulation, when they did that I had them spray the outside of the box also.

Wife’s uncle had one and it is a older model from what I remember it seem to be a little noisey and I remember that his screen on his windows were full of outside dark. They acted like a big filter. I do know that it sure move some air and it did cool the house down. If you get one hope it works out for you.

Similarly, I am putting in just a good Attic Space fan. With my wife’s allergies/asthma, I need the keep the house pretty much closed up and central air running April-October. But my attic get so hot, even with extra vents I installed and a Wind Turbine.

Good Luck with it.

Put one in when I built my Two story house. Mounted it in the second floor above the stair well. The reason I did is because I once rented a house in southern Wi., and it worked so well I rarely ran the A.C. What I also did when building my house was to put stationary vents in one gable end, and a thermostat controlled gable fan in the other end. That way when the whole house fan sends the hot air up, the gable fan exhausts the air by sucking outside air from the gable vents. Works great. My house does not currently have A.C., and there has been only a handful of days each year in which I wished I had A.C. Hope this helps.
Walleyebry #993

When I lived in Georgia many houses have them down there. Much cheaper then AC and they did a very good job, saved a lot of money over airconditioning. You can control airflow by what windows or doors you open. Make sure it has variable speed, and the vents in the attic can handle the air flow. Up north hear be sure and insulate it well with a manual or automatic closure. I have often thought about putting one in I really miss it.

Several years ago I put one in the first house we bought. We lived in town with a lot of mature trees in the neighborhood, with most everything shaded. It really cooled the whole house lickety split in the evening and kept the house cool on the warmer days. Well worth the investment.

Check that off the list. Haven’t seen the cat in days either! Works sweet!

Czech, not to be nosey but, did you cut the 2x bottom cord of your roof truss?

One truss was cut and framed accordingly, offset was only 6″ or so. I think it is better off now, went kind of nuts with the 3″ screws. Not nosy, thanks for asking. I’m dangerous with a sawzall!

fwiw be careful of vented gas burning appliances (water heater/furnace/dryer/etc) while running one of these fans.

Each year we get a few calls on CO in the house and it’s caused by a negative in the house from a exhaust fan..

Al

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fwiw be careful of vented gas burning appliances (water heater/furnace/dryer/etc) while running one of these fans.

Each year we get a few calls on CO in the house and it’s caused by a negative in the house from a exhaust fan..

Al

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I’m considering this for our upstairs. You would recommend not running the fan anytime the dryer is running or the water heater is running then?

Does the size of the house have any bearing on this? Where those appliances are in relation to the fan?

Thanks!

Quote:

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Quote:

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fwiw be careful of vented gas burning appliances (water heater/furnace/dryer/etc) while running one of these fans.

Each year we get a few calls on CO in the house and it’s caused by a negative in the house from a exhaust fan..

Al

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I’m considering this for our upstairs. You would recommend not running the fan anytime the dryer is running or the water heater is running then?

Does the size of the house have any bearing on this? Where those appliances are in relation to the fan?

Thanks!

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Each house is different and so is the appliances, with that in mind…”most” gas burning appliances have some sort of safety device/s on them.

Run the fan and dryer together, if the vent doesn’t get hot, it could be back drafting, considering the dryer has a forced exhaust and limits I doubt you’d have a problem other than the dryer shutting off on limit.

Water heaters are a different story, they can back draft and not trip any safeties, although the new anti explosion models would probably shut down…maybe.

Same for furnaces, biggest problem is gas burning devices that have a draft hood, non power vented water heaters, older furnaces, space heaters are a few.

Best suggestion I can give is to buy a couple CO detectors and mount them where a adult will hear them, that goes for anybody imho.

Chances are you shouldn’t have a problem, but after 30 years in the gas field I’ve seen or heard of enough body bag situations that “shouldn’t have” really isn’t good enough…be safe.

Sorry for the rant.
Al

Great advice from Denny and Allen, both things you need to explore before installing. Our house is a split tuck under, fan is in upper hall, appliances directly below in basement. You CANNOT run this without a door or windows open, the whole point is to pull outside air in. If you do not do this, they will pull ‘air’ from where ever, including chimneys like Allen said! Also, you need to be sure your attic is vented enough to handle the exhaust. Kooty, don’t tell them what I call this fan in regards to the FW…