Callum Hoffman

how will you clean out the spiral section of the heat exchanger?....i built a top loading downdraft boiler (not a rocket type) a few years back with a spiral heat exchanger/flue similar to what you show in your drawing and it worked really well EXCEPT that it was a major mission to clean out the spiral pipe when it needed done

i built a Babbington Ball waste oil fired boiler to heat my house last winter.....if you are going to build a babbington ball version of a Rocket stove be aware that a vertical riser with no gas flow restriction will probably have a issue with the flame 'running away' down the tube and up the riser before flaming out= smoke out city lol....the 'draw' that a babbington generates has to be seen to be believed