Indirect Evaporative Coolers

evaporative coolers
(also called swamp, desert, or air coolers) are devices that cool air through the simple evaporation of water. They differ from refrigeration or absorption air conditioning, which use the vapor-compression or absorption refrigeration cycles.
(Evaporative Cooler) An evaporative cooler cools by adding moisture to the air. In low desert areas most people find they provide an acceptable level of comfort before July 1 and after September 15, most years. In higher elevations they may provide comfort year around.
(evaporative cooler) a cooling system that cools by evaporation

indirect
having intervening factors or persons or influences; "reflection from the ceiling provided a soft indirect light"; "indirect evidence"; "an indirect cause"
Not directly caused by or resulting from something
collateral: descended from a common ancestor but through different lines; "cousins are collateral relatives"; "an indirect descendant of the Stuarts"
(of costs) Deriving from overhead charges or subsidiary work
not direct in spatial dimension; not leading by a straight line or course to a destination; "sometimes taking an indirect path saves time"; "you must take an indirect course in sailing"
Not done directly; conducted through intermediaries