IMM wrote:

"Steve Firth" wrote in message
...
Ian Stirling wrote:

Of course, if you could get small 24*7 generators, doing the CHP
thing and putting the exhaust heat into the house, and the low-grade
residum into the heat source, plus using the shaft power to run a
compressor, then that would pretty much beat anything.

Heh, I'm working on something similar. Generators work best at constant
load so I'm fixing up an immersion heater as a ballast load and planning
to run the exhaust through a coil in a separate calorifier.

The calorifier will have to be a strong, expensive stainless job. The
exhaust may rot a lesser one very quickly. It will generate much heat (the
IC engine produces more heat than turning power), so you will require a vast
amount of hot water storage to make it anywhere near viable.

Conventional IC engines are pretty close to breakeven, if they are
run on cheap fuel, and the result compared to electricity.
If you add in the heating, it can be an overall win.
(neglecting maintainance, and capital costs, which is the biggie.)

Insulation is indeed generally easier, as are many other measures
in general.