I am wondering if there is a difference in performance between the RMH systems that use a cylindrical heat riser rather than a square heat riser
I have constructed and deconstructed my RMH system twice because of poor performance. I thought I had a good draft, and the fire burned realyl well, but the barrel never really got hot. I mean of course it got warm, but never to temperatures that can radiate heat and heat up a space. ( a small space, I have, maybe 100 sq. ft) After burning the system for several hours I could still touch the sides of the barrel for ten seconds or so. So I decided to take out some of the variables and test out my J-tube core. Here are my dimensions
Feed: 15" high
Burn Tunnel: 22.5"
following the 1:1.5:3 ratio. All components with a 7.5" x 7.5" CSA
Mine is made with bricks and all is insulated with clay.
So after testing just the J-tube core I noticed that my fire does not really get very high. The highest it has gotten is just about halfway up the riser. I am wondering if something is wrong because I have seen videos online with the fire blazing out of the riser and also have seen videos of people with fire vortexes in their risers. Mine just doesn't seem to be doing that and I'm not sure if it should be. In both the videos that I've seen they used cylindrical risers, and I know the designs have evolved from square to cylindrical.
Also as a bit of side note - the hot coals build up so much during my burning that they begin to clog the burn tunnel. Is this a common thing or a sign of something going wrong with the burning.
Any tips or help is greatly appreciated!