Xisca Nicolas wrote:Josh, I did post this same question, and was told that the barrel is absolutely necessary because it is metallic!
The good conduction of the metal makes the high temperature of the smoke coming through the inside rise fall down dramatically, thus helping the draft because the colder smoke will go down on the sides.
So, with all masonry, more smoke at the beginning, more need of a good outside smoke exit, or a need of electric ventilation as seen on this video it seems.
The barrel determines if the heat is radiated immediately or not.
You must have sufficient surface area to absorb the heat w/o a barrel, or it will exhaust to the chimney, wasted.
It is the responsibility of the chimney to exhaust the gases.
All rocket heaters should have a good chimney for reliable performance.
Xisca Nicolas wrote:So, with all masonry, more smoke at the beginning, more need of a good outside smoke exit, or a need of electric ventilation as seen on this video it seems.
allen lumley wrote:
This is only my latest interpretation of what goes on within the Heat Riser, (which I think we all agree works as a 1st, primary chimney) and the Barrel, and the words are my
own, I claim no special knowledge! Everything said here relates only to the functioning of a Good R.M.H. !
Not only does a Well insulated Heat Riser create the High flow rate, high Volume flow of Hot Exhaust gases, these hot exhaust gases by their very nature is/are packed with
'potential energy' !
The rapid cooling of the until then Hot Exhaust gases, from their contact against the skin of the Top and sides of the Barrel, allows them to fall rapidly through the transition area
and flow out the horizontal pipe ! The turbulence created within both of these sections creates both more heat, and the Rocket-y sounds that you hear !
Failure of the External skin of a R.M.H. to radiate sufficient heat will eventually cause the Flow of the Hot Exhaust Gases to stall as the temperature within the R.M.H. equalizes
everywhere ! This is even more pronounced when the Heat Riser is poorly insulated, as enough heat can then leak through the Heat Risers External wall - into the area of the
barrel or exterior skin of the R.M.H. to cause that 'stalling' to occur at a higher temperature and sooner ! Massive fail, and a living space filled with smoke !
Glenn Herbert wrote:I notice your plan shows windows set deeply into the south wall. This will cause the glass to be shaded much of the day except near noon, drastically reducing solar gain. I think you would get much better results putting the glass near the exterior face of the wall.