[Red Badger]

The water out of my lawn pump comes out of the ground at around 68°F year round. It feels cold in the summer and warm in the winter. A simple heat pump or “swamp cooler” would work in Florida and other places not near magma vents.
Here’s one company’s solution:

http://www.groundloop.com/

[thackney]

I should have said: Many of the cooler areas are suitable for home size geothermal unit for some heating and cooling.

Some of the homes on the lakes around here do this as well heating and cooling.