David Corne

Devon Olsen wrote:i see nothing non-RMH about an elevated "chimney" after all the mass
the main reason i would say it is not getting draft would be taht it has no rise at the other end, for GOOD drafting to occur the exhaust has to exit higher than the feed comes in
i would first try simply making sure that the exhaust is higher than the barrel before making it higher than the whole house
the warmed air rising out of the exhaust creates a vacuum of sorts and pulls air through the rest of the setup, if the exhaust isnt higher than the barrel (theoretically the highest point in the design) than the vacuum is weak and doesn't have enough power to really pull it through and create that rocketty goodness

in a cherokee fire pit (im calling it cherokee because i forgot the name of the tribe that did this and it sounds right to me) is basically two holes close to each other and connected at the bottom, burning your fire at the bottom of the lower hole created a draft and sucked the fire up through the second hole, which was higher up, creating less smoke and concentrating heat for cooking, also saving fuel, the fire pit doesn not work very well, if at all, if the exhaust pit is not higher than the burn pit
and i think thats your main problem here, the heat goes to the highest point, working against the draft and slowing it down, also preventing burning past that point because any oxygen that does manage to get drafted in gets smothered with CO2 due to this

the idea of a rmh-if i understand correctly-is the heat riser generates thrust, or draft. should i need to add a vertical run to improve draft, i have constructed something wrong. the pursuit of excellence i as a libertarian aspires to, would be sacrificed for delusion and convenience. i would be glossing over a technological problem with a "gimmick", rather than solve the problem. knowledge is not gained by cheating.

your input is appreciated. many ways to explore a problem, and many solutions. this is the value of open sourcing.

Peter Berg wrote:

Jamie Corne wrote:It's gonna take quite a bit of energy to get that heavy smoke to to up that vertical tube...isn't it?

No, it isn't. Smoke will go up the stack when it's warmer than the outside air, that's all. Gases of higher temperature are expanded, therefore lighter and tend to rise. So this "heavy" smoke do get it's rising energy from the earth's gravity.

(Hope this is clear, I'm wrestling with the English language all the time.)

Hello Peter, and thank you for your input and continued interest.

We had considered a vertical run for a temporary solution, which would make our rmh into a conventional woodstove with a heat exchanger, but that would be to admit defeat. we are determined to have a honest to goodness rmh.