I agree with you guys.The information on the web sites and several heating and cooling contractors that I have spoken to, tell you to look at it differently from how we would believe this to work. My thinking was the same as Russ, If the water temp is sitting at 34 to 40d that this would tend to cool the heated water from the earth,the theory is that the surrounding water actually works as a conduit ( even better than the earth its self) drawing the heat out. every hvac rep I have spoken to claims the pond or underground well source is the best and cheapest route to go.I am not real fimilar with heat pumps, Nick has probably delt with a few living in Texas.My understanding is that the heat pump works well until the temps dip below 10d then your in trouble. But through the ground or your pond the temps never dip below 50 or 55d underground (in southern Ia) Take a look at this photo to get and idea of whats actually going into the pond
http://www.morrellcompany.com/services/geothermal.html ( it should be the bottom photo ) one way it was explained to me.. think of a hot frying pan sitting out at 70d in the air to cool, now take the same hot pan and put it in a 70d pan of water. which cools the pan faster? Thanks for the input, fellas.
