[TriLUG] OT: thermodynamics of A/C question

[Joseph S. Tate]

I'm just skimming the thread, but two points I think that have been
missed or misunderstood.

1) evap. cooling works best with drier air not because of heat
absorption, but because water when it evaporates absorbs a lot of
energy.  This energy sink is much more significant than the deltaTs in
heat transfer, so evap cooling doesn't work in high humidity climates.

2).  Cold ground water is still warmer than cold air in the winter,
and Heat Pump efficiency is related to temperature differentials: dT
for groundwater to internal home temp is only 30°, whereas air temp dT
is 60° or more on cold nights.