StillSmart

Something completely different but similar...

I would like to recover heat out of a chimney. If I put a copper coil around it and started the syphon, both ends under the water... would the heat create an auto syphon?

I am assuming that you mean a flue liner and not a brick built chimney. you do need to have thermal transfer through the chimney lining into the coil. unless you put the coil directly into the flue gas - in which case you do need to pay attention to the solder. exactly the same as a steam boiler.

however in principle it is sound. personally i would suggest a flue gas heat exchanger, probably a variation of a dephlegmator as opposed to a simple coil, but that is just me being fussy. again!!!!

Thanks Myles.

The idea is a log stove with a 6inch steel flue, wrapped in a copper coil. The plan is to be able to heat water in a bucket by dropping both silicon hose tails it in.

Was this your thinking...
http://www.esru.strath.ac.uk/EandE/Web_ ... ue-hx.html