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Comment by mrfusion | Hacker News Reader

Has anyone installed a whole house fan? I've heard they can rapidly cool your house to the outside temp at night?

I can't decide if it would hurt resale value too much to have a giant fan vent in the middle of the ceiling though.

We've got a whole house fan and it's awesome. We live in a climate that cools off nicely at night and it works like a charm.

We do run the AC for a few hours on really hot days to 'cut the top off' of the heat, but at night the whole house fan comes on. We can then go a large part of a really hot day by managing shades and windows and the house stays nicely cool.

I grew up in a house that had one.

Pros: Really effective at temps below 95F; Way cheaper to run than central air (but variable flow mini-splits might be closer).

Cons: Noisy; Sucked in dirt & dust from outside; The closed metal louvers didn't provide any insulation in the winter (so we had to put an insulated box over it); Didn't help much when humidity was sky-high.

Might be a good option for overnight cooling in a house with battery-backed solar (would have to run the numbers to see).

Keep in mind that (courtesy of the (aeronautical) engineer buddy o' mine) one of the, if not the primary, costs of air conditioning is condensing water out of the air in even moderate humidity.

If you open your house to the outside at night when it is cool enough, you may be allowing moisture into the house which will cost you more during the day when the AC is running.

Note: your mileage may vary.

Yes. They are great for certain sized homes. They can cool off a house pretty quickly in the evening provided it's cool outside. Installed with whirlybirds on the roof and it also provides the benefit of pushing out the blanket of hot air in your attic to keep temps down... The only cons are how loud it is and the fact that it's uninsullated.

I lived in a house where one was installed. It could cool down the whole house in half an hour. Operation was noisy.

We had one when I was a kid. It really moves the air through the house and can be effective in the right circumstances. Also, it's awesome to fly paper airplanes into.

My apartment has one, but it's too loud to run it overnight. The vent itself doesn't seem like a big deal though. It falls shut when the fan isn't in use.

Can it cool down your place really fast? For example in my house, when it's 80 degrees inside and 65 outside, I can open all the windows, and it gets down to 75 overnight :-(

They move a lot of air and do cool things down quickly. Just make sure there aren't any fresh skunks outside before you turn it on.

I don't know. We don't run it overnight. I just use a pair of box fans (≈ intake + exhaust) to push cool night air through my room.

It has louvers so when the fan is off it is not visible.

We had on when I was a kid. It is much cheaper than box fans in every window and more aesthetic.

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