The geothermals are more efficient but more expensive and designed to
benefit from the heat in the earth. That's the way you should go if
you have the room and installation cost.

My estimate is that your idea would save a little on your electric
bill when the outside temp is below 40 degrees, but not nearly a much
as you might think. Maybe 3 or 4 percent for the winter.

But then what are you going to do in the summer when the green house
is hot?





On 15 Jul 2006 08:26:43 -0700, "Zaphod" wrote:

Hi Folks,

I live in lower Michigan about 30 miles norht of Indiana. My niece's
husband who does heating and cooling has talked me into switching to an
air transfer heat pump with electric back up. I currently have an oil
furnace and Iive in an old two story farm house that has about 1,500 sq
ft.

I have been thinking of an idea and have not yet discussed it with my
nephew and I thought I would post it here and see if I get any
comments.

I was wondering if the outside unit of an Air Transfer type heat pump
could be put in a small greenhouse during the winter so the air around
it would be warmer during the day?

Or maybe even put the outside unit in a small enclosure and run vents
from the house to it so that when the heat pump is warming or cooling
the house it would also be warming or cooling the air around the
outside unit?

Would this even help at all in keeping the electric use down?

Thanks, David