Here’s a picture of our geothermal heat pump, at least the basement part. A large loop of pipe goes underground outside the house and a liquid in the pipe transfers the ground temperature (55 degrees) to the heating system, so the heat pump works very efficiently. The same method is used to cool the house in summer.
We also use a wood stove, often in the evenings, which makes the living room more cozy, but on lazy days the heat pump does just fine.
A book that was helpful in our research is Natural Home Heating by Greg Pahl.
Neat.
Comment by Eric — February 1, 2010 @ 9:25 pm