GregP asks:

My Father in Law had a ground water heat pump installed on his farm.
It extracts its heat from ground water which is supposedly at 55
degrees year round. It was efficient but you had to return the water
you extracted some distance away from the source to prevent the
gradual lowering of the temp from your source. Not much of a problem
if you have the land but a pretty big one if you don't.


If it's a heat pump system, couldn't you also rig it to lower
air conditioning costs in the summer

Naturally.

Charlie Self
"It is when power is wedded to chronic fear that it becomes formidable." Eric
Hoffer