Safe to run a box fan face down? (sopuli.xyz)

submitted 1 week ago* (last edited 1 week ago) by [email protected] to c/[email protected]

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My business has a swamp cooler (evaporative), but none of the windows open so I have no way to vent air. There is a vent in the alcove (?) over my front door facing downward. The vent is about the size of a box fan. I have been thinking about putting one face down on top of the vent.

If this is not a good idea is there a better option? I have an outlet not too far from the area, but do not think that there is anywhere near to hard wire. I could run a wire out the vent for a solar panel, but the awning is north west facing.

Vent opening:

With fan laying on top:

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[-] [email protected] 5 points 1 week ago

Aside from premature failure, the actual answer to your question is: Yes. There are no inherent dangers to running a box fan face down.

[-] [email protected] 4 points 1 week ago

Box fan bearings are not typically designed to run in that orientation. It will probably run for a while before failing prematurely. Might make it a couple months or just a few weeks.

This is a much more robust fan and they come in various sizes to better fit your opening. They move a lot more air, and many styles come with a thermostat and speed controller. Sorry for the Amazon link, this is just the general style: https://a.co/d/bLeBCeD

[-] [email protected] 2 points 1 week ago

And that one will be okay laying to push air down?

[-] [email protected] 9 points 1 week ago* (last edited 1 week ago)

Anecdotal, but I ran a box fan in that exact orientation (facing/blowing down) for years with no issues. I used it for an overhead fan in a garage.

[-] [email protected] 2 points 1 week ago

The bearings are much sturdier as the fan is bolted to the motor, and the motor is a generic one meant to be used in any orientation. I personally bought [this](iLIVING 20" Wall Mounted Shutter... https://www.amazon.com/dp/B0BVY8VCNZ) one for my house to cool it in the summer and at half power, every open window in the house has a stiff breeze.

[-] [email protected] 1 points 1 week ago

Thanks. I will look into that, but at that price 2-3 box fans over the summer would be a better way to go.

[-] [email protected] 2 points 1 week ago

You could always build a plywood box/cube thing to duct the airflow downward, but with an opening on the side so you can use any cheap box fan.

[-] [email protected] 1 points 1 week ago

That has been a thought too.

[-] [email protected] 2 points 1 week ago

If you don't care how it looks, and you're specifically blowing air in with the box fan, you can just use a large garbage bag to direct the air in. Mount the fan vertically facing the opening, cut open a trash bag, and attach it to the remaining three edges of the opening and your fan.

If it's stupid and it works, it's not stupid.

[-] [email protected] 0 points 1 week ago

A vented security door would work better.

[-] [email protected] 1 points 1 week ago

It is an old building with odd sized everything, and I have to get the landlord's approval for anything like that.

this post was submitted on 30 May 2025

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