On Tue, 8 Jan 2008 06:15:14 -0800 (PST), wrote:

I'm still to be totally convinced by heatpumps. COPs of 4 and even 5
are advertised by manufacturers, yet the only real world figures I've
been able to find are 2 or a bit better - and that's ground source
with UFH and plenty of insulation.

I'd agree, they only really make sense in a new build where you are
installing underfloor heating and you don't have mains gas and don't
want an oil tank or are worried about future oil price. Compared with
bulk Propane or electricity they would be a good choice but not
otherwise.