I went to lowes and bought a 5,050 BTU Air Conditioner for my grow room for $90. My room is 4'X12' and it keeps it plenty cool. without it, my room would be like 95F++++. this thing works great. the hot air that is taken out of my grow room is put into the rest of my home, and my big A/C unit in my home removes it from my house. this way I did not have to cut any holes in my walls or anything. Also the AC unit has not dripped one drop of water since I started it 3 weeks ago. Even though it has not dripped water at all, I still have a cake pan under it. Here is a picture of my AC unit.. I love this thing. uses only 6 Amps. I can keep my room as low as 62F, but i have been keeping my grow room at 75f. Lot better then the 85-95f temps my last grow.
Olds442,
what you are talking about is called a swamp cooler. And they cool the air pretty good. but they put a ton of humidity into the air. This is exactly why I did not get one. I got a Air Conditioner unit. they do not put humidity into the air. They actually remove Moisture from the air if anything.