"IMM" wrote in message ...

Heat exchangers are not cheap. Many people make their own. It is using
all the heat available. Having a small LPG genny, about 1.5 kW/hr, and
extracting all the heat is feabile. But you have to extract all of its heat
and store it in a large thermal store. Then your house has to be run mainly
on LV lights, run from batteries overnight with the genny off, and all
appliances run on gas (gas fridges are available). Washing machines, etc,
have to be super energy efficient and hot and cold fill, with the hot water
comming from the stored water. No appliance should draw more than 1.5 kW.

Now there are Combined Heat and Power Stirling units available.
http://www.whispergen.com
http://www.microgen.com/products1.html

Excellent sites well the first one was excellent except that it gave
no clear idea of the size weight and price. Ditto the other one but I
couldn't get on with the way the pictures loaded.

I'd never heard of the stirling engine and am having difficulty with
the concept. They seem to be shooting themselves with the overbuild
quality as a fuel efficient small unit that wears out rapidly would
sell if it was cheap enough to supply a site. It could be without the
heat saving ad ons.

Of course the firms shown were designing a unit for specific purposes
not including what I would buy one for. If I was in the market for a
genny.

I wonder why they can't incorporate an oil way in the crancks and etc
the way that motorcycle 2 strokes do.