Cooler water will actually evaporate faster in warm/hot dry air, just as warm water freezes faster in cold air due to the temperature spread. The "boil" of bottom diffused air will cause cool water to evaporate faster.

The heat transfer rate is proportionally faster the wider the temperature differential is. The small bubbles of the diffused air that help lift water also provide a huge surface area for the heat to transfer rapidly.

Last edited by Rainman; 09/28/15 12:13 PM.