# How fans keep the heat out

**URL:** <https://boards.straightdope.com/t/how-fans-keep-the-heat-out/62995>\
**Category:** Factual Questions\
**Created:** [April 23, 2001, 2:25pm UTC](https://boards.straightdope.com/t/how-fans-keep-the-heat-out/62995 "2001-04-23T14:25:22Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![jdl](https://avatars.discourse-cdn.com/v4/letter/j/4bbf92/32.png) [@jdl](https://boards.straightdope.com/u/jdl)\
**Post date:** [April 23, 2001, 2:25pm UTC](https://boards.straightdope.com/t/how-fans-keep-the-heat-out/62995/1 "2001-04-23T14:25:22Z")

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I remember seeing something on TV many years ago about a way you could setup electric fans to keep the heat out of your apartment.

I think you had to have one pointing sideways on the windowsill and maybe another pointing towards the window. Or something like that.

**Does anyone know the best way to position (non-ceiling)fans to keep a highlight apartment (with no AC) cool in the summer?**

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**Author:** ![Skelji](https://avatars.discourse-cdn.com/v4/letter/s/b38774/32.png) [@Skelji](https://boards.straightdope.com/u/Skelji)\
**Post date:** [April 23, 2001, 3:40pm UTC](https://boards.straightdope.com/t/how-fans-keep-the-heat-out/62995/2 "2001-04-23T15:40:09Z")

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I don’t know if fans alone would actually keep an apartment _cool]_…maybe just less warm than no ventilation at all.

One way to try would be to set up fans in windows at opposite ends of the apartment - one being an intake fan, and one an exhaust fan. If possible, you should have your intake fan on the shady side of the building, depending on the time of day.

Depending on room configuration, you may need to position additional fans to deflect air off of walls to achieve maximum circulation.

I used to live in an apartment that didn’t have central a/c. I got a cheap window air conditioner and put it in the bedroom. At least I had one room to go to for relief.

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**Author:** ![hibernicus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hibernicus/32/2802_2.png) [@hibernicus](https://boards.straightdope.com/u/hibernicus)\
**Post date:** [April 23, 2001, 10:28pm UTC](https://boards.straightdope.com/t/how-fans-keep-the-heat-out/62995/3 "2001-04-23T22:28:40Z")

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There is no way you can arrange a fan that will make your apartment cooler. The electric motor will increase the temperature of the apartment.

_However_, a fan in your apartment will make _you_ cooler. This is because evaporation of water (sweat) from your skin takes heat away from your body. Increased air-flow leads to increased evaporation.

Therefore, the correct way to arrange the fan for maximum cooling effect is blowing straight at you.

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**Author:** ![xash](https://avatars.discourse-cdn.com/v4/letter/x/c6cbf5/32.png) [@xash](https://boards.straightdope.com/u/xash)\
**Post date:** [April 24, 2001, 1:03am UTC](https://boards.straightdope.com/t/how-fans-keep-the-heat-out/62995/4 "2001-04-24T01:03:05Z")

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here’s what we used to do in our hostel rooms in college…throw a bucket of water all over the floor…find a movie or someone else’s room till it dries…seemed to cool the room for us…some in the hostel had the theory that if we water the room above us it would cool the room below ( ours )… we didn’t have the apparatus/patience to test whether that theory held any water 🙂