- unless it is covered somewhere else on Permies!!
I am working on designing (building soon) a RMH
totally enclosed within a 55 gallon drum. J-tube at the bottom, insulated riser in the back. Then the heated gasses do a 180 back down into the drum - making a 90 just above the burn chamber and across the lower 1/3 of the barrel to another 90 degree turn then out the top. All these three runs within the barrel will be surrounded by mass for radiant heat. The top would have a heavy 1/4" plate welded on for cooking or a cast griddle sitting on top. To preserve heat when not cooking a round 2" piece of soap
stone or other mass would be placed over the cook surface.
Question: Would a 4" j-tube generate enough
heat to "fill" this mass or should
it be a 5" j-tube and insulated riser?
I'm guessing a 6" would be difficult to fit inside the barrels space and make all the turns needed.
Secondary idea - rocket stove
in a bottom 55 gal barrel with a 2nd 55 gal drum on top that is insulated as a bell. A 30 gallon stainless barrel enclosed in the top barrel as a water heater
with three or four hollow stainless 3" tubes welded into the bottom of the stainless 30 gal drum for more surface area to heat the water
. So this 30 gal stainless tank will likely be a 25 gallon water heater after accounting for the inner heat exchanger tubes.
This stove could be a 6" box and riser or a small batch box and 6" riser to generate the heat and duration of heat needed to heat 25 gallons of water.
This idea is born from the following requirements:
* Compact design for a small space, but still has some mass to it for extended warmth (fire once or twice a day)
* A gravity fed rain water catchment system will feed
the water heater design
* No pumps used - this kind of excludes using coiled pipes that circulate into a holding tank - the holding tank is the heater in this design