Restoration is easy.

[Nick]

Yes! Nick's heat pump is impressive, neat installation. But as said you need the land (No! not enough) and the number of years (No! not enough) to pay back the high cost of installation.

Installation was the same as a standard boiler - the ground-works were done in a morning - I admit, I had the diggers on-site as we were rebuilding the house at the time - 3 x 50mtrs trenches, 1mtr deep, 1mtr wide with 4 inches of sand in the bottom - each trench has 200 mtrs of alkathene pipe laid in a "pushed over slinky" - each trenches' pipes are in parallel and fed back to the heat pump - pipes were in and trenches backfilled by end of same day.

I monitor all power & energy use in the house and log it - for every kWh we put into the system, we get over 3kWh of energy out - a CoP of 3 - the heat pump system, compared as best I can with the previous oil-fired condensing boiler, paid for itself in just under 3 years, 6 months.

Not bad at all... and far far better than normal solar heating (payback about 21 years).

You can also get "air source" heat pumps that do not use underground pipes - not as efficient, but pretty good none-the-less... a heat pump uses normal plumbing (unlike roof-mounter solar heaters) and is generally a "set-and-forget" type system - it learns the thermal characteristics of your property and adjusts accordingly...

I spent a while at the Centre for Alternative Technology in Wales before doing all this - they agree that heat pumps are the only system that make sense both technically and economically on a domestic scale... (forget wind turbines, roof solar cells and electric solar panels - all madness).

EDIT: You do need the right sort of house to get the best from a heat pump - its a very slow & gentle heat - if the house is poorly insulated or draughty then the heat pump is a no-go. When we rebuilt it was to modern insulation standards and the whole of the new part of the property is built as a concealed thermal store - the floors are basically 2'6" thick storage heaters... (block&beam, UFH & screed)

See http://www.heatpumps.org.uk/PdfFiles/The...tPumps.pdf for more info.