Stuart Hoenig, an electrical engineering professor at the University of Arizona, is exploiting water's ability to be easily ionized in his improvement on the basic design of evaporative coolers.
The new design places an electrical gradient across the input side of the cooler. Water in the incoming air (assumed to be 90°F and 85% relative humidity) is charged, and charged air ions are attracted to a grounded screen or an array of electrified needles. Ions collect, drops form and they fall into a collector. Relatively dry air (24% RH) is then drawn through a wet porous medium, dropping the air's temperature by 25°F and raising humidity to 35%. Not only does the system improve the cooling capabilities, it also destroys bacteria and removes dust from the air.