Is Using Water to Cool a Room Effective?

[Renaatier]

Hey all,

Bear with this stupid question. So I noticed that my apartment is currently 85 degrees, and my tap water is currently 65 degrees. I looked up the volumetric heat capacities of water and air, and found that water has approximately 3200 times the Joules/(Kelvins * cm cubed). So if my apartment is like 6400 cubic feet, would it not be at least semi effective to douse my entire apartment with 2 cubic feet of water, spraying it on all the walls, carpet, floors, to maximize how fast it absorbs the heat? Before I go dumping water in my apartment out of desperation and making a fool of myself, I was wondering what you all thought on the subject.

-Renaatier

 

[rcgldr]

It depends on the relative humidity. Wiki article:

http://en.wikipedia.org/wiki/Evaporative_cooler

 

[Renaatier]

It depends on the relative humidity. Wiki article:

http://en.wikipedia.org/wiki/Evaporative_cooler

I would consider the heat/humidity exchange about even an even trade in terms of comfort levels, in my climate. I know that a certain amount of heat from the air would be absorbed in the process of vaporizing the water...

But I'm still wondering about the other component--the process of thermal entropy involved from dumping the cooler water all over my hot apartment. Since the temperature difference is sizable, and water has a much larger volumetric heat capacity, would it be effective at absorbing the heat from the air in a noticeable way?

 

[russ_watters]

I would consider the heat/humidity exchange about even an even trade in terms of comfort levels, in my climate.

Is your climate very dry? Because if not, you really won't like the end result...

But I'm still wondering about the other component--the process of thermal entropy involved from dumping the cooler water all over my hot apartment. Since the temperature difference is sizable, and water has a much larger volumetric heat capacity, would it be effective at absorbing the heat from the air in a noticeable way?

The temperature difference is not the key, it's the latent heat of vaporization of the water that absorbs most of the heat. In any case, this works well for very dry climates. Devices that do this are often called swamp coolers: http://en.wikipedia.org/wiki/Evaporative_cooler

 

[creyc]

If you just wanted to use the temperature difference from the water maybe a heat exchanger would work, with the added benefit of not getting your appartment sopping wet..