Ah yes, that did the trick thanks Cicero.

I came across something quite interesting in Poland which looks like a
massive investment in this technology.

http://www.ebrd.com/projects/psd/psd2005/35540.htm

It looks a bit tidier than a lot of Eastern European district heating
systems where a "goalpost" bend in the pipe indicates an entrance;-)

Cicero wrote:


==================
I don't know of any particular source but you might try 'googling' for
'district heating' which seems to achieve what you're looking for, although
on a much larger scale.

Cic.


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