"IMM" wrote in message ...
"Rick Dipper" wrote in message
...

Some info about heat pumps:

Electrically powered compression type pumps can do 3x to 4x heat
transfer, but this is a max figure, and drops as outdoor temp falls.
Thats the gotcha.

Gas powered absorption pumps are hopelessly inefficient, and are
simply a non starter for space heating.


Soil heat recovery systems are even cheeper .............
400% efficient, for each 1 unit you put in, you get 4 out - wow !!

The capital cost of a ground source heat pump is horrendous. The payback
period is looooooooong.

Air source is way cheaper, and sounds diyable. Does someone here know
more about it?


BTW one form of heating that can pay is flat plate solar space
heating. You'll still need the convetional CH though.


Regards, NT