On Mon, 05 Jul 2010 10:44:05 +0100, Tim Watts wrote:

Given that air source heat pumps are routinely installed in the
USA, I
don't really understand what the issue is.

Which bits of the USA though? Cold northern areas or generally warmer
southern climes?

And which way are they pumping? Outside heat in or inside heat out?
B-)

--
Cheers
Dave.