Once in a brick veneer house I had was freezing on a sunny winters day, I then left the house to find it quite nice outside, I then thought about a system of using a solar water heater to then warm the house. Then thought, OK but most of year we are trying to keep the cool so what would you do with with the hot water? I then wondered if, in the hot weather you could use the hot water operate a refrigeration unit, like the gas fridges once popular in caravans, to use as air conditioning? I am sure it would work, but would you get enough heat out of the hot water to be effective? I was thinking of running the air though a evaporative type air con first, so the refrigerative part would be more of a condenser than a cooler. I would be interested if any people with good knowledge of heat transfer would comment on this.