We use the same thing here in the southern california desert (I live about an hour's drive north from california city) as inexpensive air conditioning, called a swamp cooler. Water is pumped over a pad that air is blown through. The evaporation of water in the low humidity conditions will reduce the temperature from over 110F (44C) to about 85F (30C) using only the about of electricity to run a small blower. It does use quite a bit of water, and only works in very dry places.