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View Full Version : Heavy Theoretical Reckonin'



rubah
09-25-2007, 05:34 AM
Do you think fans cool better in dry or humid air? Provide some logical reasoning for your stance!

I'm only guessing there's a difference. I know sometimes fans don't cool much and sometimes they freeze you. My guess is that they work better in dry air, where the air doesn't hold much heat anyways (not much water) and can get away from you to lose that heat elsewhere faster.

That brings up a sub-question; if my hypothesis is correct, then humid air holds much more (heat)energy at the same temperature than dry air. How do you calculate that?

blackmage_nuke
09-25-2007, 07:20 AM
You know when you come out of water and its freezing?, thats because you're wet and the wind blows heat carried in the water off you.

So i would assume humid air makes you wetter and thus it's more coldefying you when it's wet in the air. But i could be wrong as the moisture is in the air and not on your body...

Araciel
09-25-2007, 07:25 AM
well since the moisture is in the air, wouldn't the fan just blow more hot, humid air onto your skin?

the fact that the air moves more quickly around you does cool you to a degree, because it removes some body heat by blowing it off you, but if the air is as hot or hotter than your body, i doubt it would do much, and humid air feels hotter, so...

The Ceej
09-25-2007, 06:17 PM
A fan doesn't actually cool anything down. What a fan does is circulates the air. If you're in front of a fan, you're right where all the air is coming from. It's blowing on you pretty hard. In many instances, the air seems cooler because it's moving faster. Like a breeze. However, if the air is too hot, it still won't make it feel much cooler. So, how cool a fan feels has nothing to do with moisture in the air, but rather wind chill. It's a relative temperature change based on actual temperature versus wind speed which makes you feel cooler. I hope I'm clear enough in this explanation as I don't have all the correct scientific terminology off the top of my head.

Heath
09-25-2007, 08:08 PM
Your hypothesis makes sense to me (even if I lame at Physics). God (e.g. someone good at Physics) only knows how you'd calculate it though.

rubah
09-25-2007, 09:06 PM
A fan doesn't actually cool anything down. What a fan does is circulates the air. If you're in front of a fan, you're right where all the air is coming from. It's blowing on you pretty hard. In many instances, the air seems cooler because it's moving faster. Like a breeze. However, if the air is too hot, it still won't make it feel much cooler. So, how cool a fan feels has nothing to do with moisture in the air, but rather wind chill. It's a relative temperature change based on actual temperature versus wind speed which makes you feel cooler. I hope I'm clear enough in this explanation as I don't have all the correct scientific terminology off the top of my head.

It feels cooler when it moves faster because it is moving heated air away from you :p