an engine is 100% efficient (energy and matter are neither created nor destroyed only changed in form) so if you want to make use of more than just crank power (generator, driveshaft, etc) then you should definitely use the other energy sources like heat that the engine produces.
That is exactly where I was going with my previous post. The engine could provide electricity, it will run on almost anything, you could circulate coolant through a large loop for heating (though this type of heat does not adjust well and takes a long time to heat the space if its cold). If you dont want to listen to the engine run, put it outside or in a sound proof enclosure.
It is easy enough to pipe heat exchangers (for air or domestic hot water) to this location and you would have everything in one "mechanical room" maybe a detached shed or similar. All pumps, tanks, compressors, exchangers, fans, etc would be located there for ease of operation and service, etc.
What was used for the "generator" portion of the genset pictured on the previous page?
Unless you have a massively huge house with no insulation 100kw is way overkill for a house. You should be able to run the basics on 5-7kw and turn on everything in your whole entire house at once should only take 15-20 kw.
