cezar blimpyway

Hi, thank you Allen for the warming welcome.

My heating needs are quite low, it's a 150sqft, lightweight (litle mass in the walls), well insulated cabin, which could be easily kept warm with a 500-1000watt continous heat source.

I'm hesitant on just using an existing, proven rocket heater design since I feel the 8 and even 6 inch flue, full 50 gallon barrel with 2 tons of bench storage are too much - overheat and overweight - for such a small space.

From Janto's book and other good sources I found that the mass heater isnt easy to scale down but still, if most of the heat of combustion could go into mass storage then it might be usefull.

Finding how much % of the heat is imediately released through the barrel and how much of it goes into the mass storage is as simple as measuring flue temps in three points: combustion zone, the passage between barrel and bench and the exhaust from the mass bench.

I have found figures for combustion and exhaust temperatures, but not in between.

thank you

By rad you mean radical? Can you share some more, like how much fuel in a load, how long does it lasts, how clean is the exhaust on low power and... pipe temperature at the bottom of the barrel?

Why do you call it "mini"?

Hi everyone, this is my first post in permies forums.

I am also interested in finding more about what temperature have the gases as they leave the barrel into the horizontal pipe, the one usually covered with cob for mass heat transfer.
I'm interested in it because I suspect that between the max 600-800 centigrades (or more?) in burning zone down to the 40-70 centigrades at exhaust, the most significant drop is inside the radiating metal barrel. That would make the rocket more of a direct heater stove instead of a mass heater.

One simple way to increase the temperature of gases entering the benchis to simply reduce the heat lost through the barrel, by using a smaller barrel and/or covering it partially, at least after the room is hot enough.

All other sizes being the same, the 8" flue will draw almost twice as much combustion air, and fit twice the wood in combustion zone as the 6"... that means twice the power. Shouldn't the exposed convective metal surface (barrel surface) be half size too for a 6 inch pipe?

regards,
cezar