Water has a very unique characteristic as it goes from liquid to steam. It takes something like 7 more times of heat to evaporate than to rise 1 degree under the evap temp. Like evaporating sweat takes away heat, the old swamp coolers were built into the upper part of a building and water evaporating in the heat (of higher in the building) carried away heat with it.Thus trays of water near the vents in a roof would act as a heat transfer mechanism that would draw in new air, if this air was geothermally controlled it could be drawing in cooler air as well. An AC blueprint- sorta.
