An evaporative cooler is a devices that cools air through the simple process of water evaporation. These units – also known as swamp, desert or air coolers – differ from refrigeration or absorption air conditioning, which use vapour-compression or absorption refrigeration cycles.
In the US, small-scale coolers of this type are known as swamp coolers by some because they produce humid air conditions. Another name for these is “sump cooler”. Air washers and wet cooling towers use the same principles as our evaporative coolers – but these are optimised for purposes other than cooling air.