Heatpump infomation

[heatpumper]

Hello,
would like to build a air to air heat pump for domestic homes.Can any body help with uptodate practical information source.
Better still; an Engineer who Knows heat pumps I can contract to undertake this project I would be glad to hear from.
Charles.

[rbartlett]

What are you trying to achieve as the air-air HP market is pretty well sourced already?

IE I'm struggling to remember the last time we sold a 'cooling only' system...

Cheers

Richard