I have a 2.5 foot tall barrel and i would like to use it as the barrel for my RMH, from what i have read it seems that the taller the heat riser the better the performance. I am only heating a small space so the exhaust run could be short.
so my question:
can you create a rockety burn with a very heavily insulated but only 2 foot tall heat riser?
and if so would this work better with a larger internal cross sectional area, perhaps 8in?
I don't know what the minimum is, but I should think that your heat riser can be rather taller than the barrel. that might allow even more insulation surrounding the portion of the riser that is below the barrel.