My name is Don Walker, I am from Indiana, and i am interested in Rocket stoves and have some Questions that i have,about a idea i have,but i do not have the money to make a mistake, maybe you have seen this tried before. My idea is merge a rocket stove mass heater desighn and a outside boiler, if i build a stove that is inside of a water tank, would the water, around the 55 gallon barrel , cause any problems with the draft or not let the stove get up to temp. that it needs to work correctly. i ahve been building a boiler ,with a friend ,for his house and it is a beast. holds 700 gallons and holds 1.5 rick of wood. we are hobby loggers and wood is not short in hand, but thats not what i'm about. I like the way ppl in your way of life style,handle things and would like to build a new style of outside boiler that would use less wood,smoke less and be more friendly to the earth. i also have a wood feed idea for this desighn,but if it will not work,no need to work on that. Please give any help that you can. Thank You. Don Walker
I would go with K.I.S.S. on this one and just coil copper around the 55 gal barrel and let it thermosiphon into an insulated holding tank. heat your house and heat your water! and in the summer do the same except with the solarhot water heater. i have a black hose in a glass box on my roof and its been a jewel!
Dont put a coil around the barrel put the coil around the exhaust and use the thermal siphon. dont put a jacket around the barrel it cools the system to fast and you get soot. hmm i have said it before if you are going to put water as the mass dont use cob cause you are already heating a mass. also dont wrap the barrel in a coil it's not controllable. instead wrap the coil around the first 5 feet of exhaust duct and build a well insulated box around it. thermal siphon it to your insulated tank keep the flow going from tank to coil. adjust the flow to get the best heating of water in the coil without it flashing to steam. make sure you dont have any moving parts to break down. you should be just about at boiling in a 1/2 inch tube by the time you get to the end of a 5 foot section of tubing. cold in the cool end and hot out the hot end closest to the stove so your siphon gets the benefit if the heat and you dont end up cooling it down before the tank.
If you want a batch heater plumb a pipe through the tank like a gas hot water heater and run it off the heat riser. wont be as clean as a RMH but this method works well as long as you dont have a pressurized tank.
Need more info?
Ernie and Erica
Wood burning stoves, Rocket Mass Heaters, DIY,
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As a general note: This is expert territory - meaning training and experience.
I've done minor plumbing (replace faucets, stop a leaking toilet) and have a degree in physics. My favorite way to heat water on a rocket stove is a large kettle or pot. Although I hope to learn more eventually (and have really enjoyed online research and working with experts like Caleb and Ernie), at present I would much rather take sponge-baths than try to build my own water heater. My grandmother did just fine with bucket-baths both in youth and in old age. It's safer for many reasons.
It's not that hard to heat a large bathtub, either, if you are willing to haul the fuel. You can do some quite clever immersion heaters or batch-heated water (like an ancient laundry cauldron), without needing to re-invent indoor plumbing in an off-grid situation without reliable power for pumps.
If you have never done water heating with natural fuels, consider that the heat output based on different types of firewood can fluctuate by a factor of 4. You do not want a "super-efficient" piped heat capture system, because overheating and steam explosions are your biggest risk factor. Big tanks like a stockpot over the stove, a Mexican hot water heater, or the Lawton demonstration system are good capacity buffers so you have some time to stop the fire before it overheats. (Gotta learn the name of the guy who maintains Geoff's system! I think it was a collaboration, or Geoff is showing off someone else's design on his site)
I would suggest that most people are better off starting their hot-water-design careers with steps like installing a factory-made system, or building a kit with well-known design rules and a predictable max. power input (like solar hot water or refined fuels). Then work up to the point where you can anticipate how much water you'd need to buffer a variable-input system like combustion fuels.