It is the evaporation of the water that cools the air just like when your sweat dries off your skin it cools you down.
Now that works well except for when the air is saturated and can not hold anymore water, then it just blows wet air.
yep when its hazy out side and humid it dosen't work
![](http://img372.imageshack.us/img372/3654/picture2573zz9.jpg)
You can see the Kat houses in the distance. Along with the heat haze over the mountians.
unclejpl4x4 the temp dropped 15 degrees when I tured it on. a cool 72 now