On Fri, 29 Oct 2004 14:07:02 -0600, someone wrote:


Actually, there is a new version of heat pump that works quite well in very cold
climates. I was able to look at one installed in North Dakota last summer.

The traditional air vented pumps do not. The newer geothermal heatpumps use
multiple wells with a closed circulating coolant running 100-200 feet
underground.

They are nothing new, back when I was in college in the 70's, one of
our class projects wasw design of a geothermal heatpump system. I was
indeed talking about the "usual" air system. I doubt that geothermals
are even 1% of the actual in service installations, so I omitted them.
Their capital cost is huge compared to a "normal" system. They don't
work for every site either.

Glad you got your in.

-v.