auto reversing window fans based on external temperature?

[markm75]

Do they make any window fans that can be electronically reversed, like this one:

Where, if the outside temp hit a certain temperature, it could reverse and blow the cooler air into the room, or if it were hotter outside, it would go in the direction to suck hot air out of a room to the outside?

Thanks

[metspitzer]

Flip the plug. No wait! Flip the fan. :)

[Edwin Pawlowski]

All window fans do something like that. They suck the hot air out and suck the cooler air in other windows at the same time. You just have to learn how to balance the right windows for maximum effect. You also need a proper window fan with side baffles and not just a box fan sitting on the window sill for maximum effect.

[markm75]

Well i'm trying to find a way to get my ambient temps down in my office, about 9x12 foot.. it houses alot of computer equipment.. i have the cpu case up on a shelf about mid level.. its close enough to the one (of two) windows in there.. i first thought about ducting the heat from the rear of the unit to the window, maybe to a fan in the window..

But i saw the link i posted earlier, figured it might help lower the temp a bit.. i guess certainly pulling cool air in the winter, not so sure on the summer.. i guess in the summer the duct work combined with it would be needed, but i wanted an autonomous setup if possible..

I also thought about an ac window unit, but those dont work or freeze up under 60F..

[Don Young]

I don't know if any are still available but window fans with reversible motors used to be quite common. I also had one with two fans so you could set one to blow each way but that was not very useful. I also had one where the fan would swivel to aim the air inside or turn completely around to blow out.

Don Young

[markm75]

Someone in a review of a holmes twin fan, mentioned that the honeywell could be set to both go inward or outward or only one fan at a time etc..

I'm assuming they were referring to this honeywell(that i posted earlier)

[Ralph Mowery]

It does not mater which way the fan blows or sucks. If it is hot outside and you try to suck the hot air out, more air has to come from somewhere. That air will come in by another window in the room or from the door. If from the door, it still has to come from the outside somehow. If you leave the door and other windows closed, you will suck a vacuum on the room, or build up pressure in the room. For a fan it will only be a small change in the pressure either way.

[Bennett Price]

If the goal is to cool the room when it's cold outside, just opening the window may do it - something you'd need to do anyway if you purchase a window fan.

[markm75]

True, but during the summer/early fall when the outside temp is say 75 and higher, i guess i'm out of luck.. short of manually setting the window fan to push air out the window..

I thought about an AC unit just for those times.. seems like a waste of $100-$350.. plus it will be noisy.

Was hoping for a truely effortless and automated solution to this.

Ambients are 77 to 85 at times in the room, though this morning after the 3 lcds were off all night, it was down to 74..

[Uncle Monster]

It just dawned on me what would work for you, instead of modifying a window unit. I've used portable air conditioners to cool small computer rooms quite effectively and there is no problem with freeze-ups because the whole darn unit is in the room. It has a big hose to exhaust the hot air. Take a look at this:

[8~{} Uncle Monster

[Uncle Monster]

If you're handy with some simple rewiring and possibly using a relay or two, you can modify the Honeywell fan. Here's a link to some items I use all the time:

The thermostat has an adjustable cut-in and cut-out that can be set for a wide range. The relays and control can obtained in either

24 VAC or 120VAC versions. [8~{} Uncle Monster

[Mike]

replying to markm75, Mike wrote: Did you ever figure out a solution?

[Gerald Fnord]

replying to markm75, Gerald Fnord wrote: I came here looking for such, but (apart from the rewiring idea by Markm75) found none such. The closest I've come is two window fans, one blowing out hooked to a thermostat-enabled 'on when hotter than' switch, one blowing in hooked to a standard 'on when dark' switch, essentially using light as prixy for heat. It might be simpler just using two timers. Inadequate, but 0.) not entirely, 1.)relatively cheap, and 2.) likely safer than having a probe out their in the elements.

Note: cheap thermostatic controllers are available for controlling reptile habitats.

Good luck.

[catalpa]

Oh No! Ten years ago markm75 got so confused about forward and reverse and hotter and cooler that he fell down the stairs, hit a spinning fan and died.