What temperature do you keep your house in the winter?

[Exeric]

Originally Posted by AC_Hacker

This is why Ground Source Heat Pumps were invented.

-AC

This is true. But your ROI has to include how many days there are in a year where really low temperatures exist. A lot of people use the principle of using the least expensive technology available that will cover 90 to 95 percent of their needs before going to a much more expensive technology that will cover 100 percent of their needs. I'm not one to decide which is best but I think both philosophies have merit.

How long you stay in your present house will enter into that equation.