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.


On 18 Dec 2004 10:57:16 GMT, otforme (Charlie Self)
wrote:

John, in MN writes:

Currently, we've got our heat pump set high enough that the gas furnace only
kicks on when it gets below 30 degs. F., here.

Thats interesting Charlie, up here in cold Minnesota heat pumps
usually switch off at about 10 degrees F . I'm fortunate enough to be
on a load shed plan from the power company and pay about 3 cents per
kwh for the heat pump. Never been shed in the winter that I'm aware
of. Maybe the efficiencies balance out different with your higher
power cost. Also have propane for alternate fuel

And maybe I'm getting screwed. Hard to tell. I was told that when the air is
much below freezing, heat pump efficiency drops dramatically. I'll have to dig
out some information on the thing, as we seldom get down to 10 degrees here, so
a setting of, say, 20 or so if it is reasonably efficient, might prove a money
saver when the guy in the rolling propane bottle pops down the drive.

We're supposed to have a guy coming out to check it fairly soon, so I'll ask
him to show me how to re-set the temp and then I can test it.



Charlie Self
"Absolute faith corrupts as absolutely as absolute power." Eric Hoffer