In article ,
"Matthew Augier \(dps\)" writes:
I've been looking at these as well, thanks for the extra info... However in
the true DIY spirit I was also thinking about somehow using the existing
plumbing and radiators to do the job. If you pumped very cold water around
the house would this actually generate any coolness from the radiators? Any
other ideas for cooling the whole house (split ac's are good but only
designed for one room?)

You would need fanned radiators, and you would need something to
collect the condensate. Then you just invented a fancoil unit.
Also, you need to insulate all the pipework very much better than
you ever do with central heating, otherwise you will have
condensate dripping off every tiny gap or crack in the insulation,
looking rather like it's all leaking.

--
Andrew Gabriel