Rocket stove

[magic_bus]

Wondering if anyone has ever tried to build a rocket stove on a school bus?
Being they are able to easily carry loads, it would seem these could be a great alternative for heat.
In case you may not know what a rocket stove is----->
http://www.richsoil.com/rocket-stove-mass-heater.jsp
I bet it could be adapted for mobile use using many scrounged free or almost free materials.
hmmmmmmmmmmmmmmm.........

[travelinwithus]

Hmmm. is right, that looks interesting.

[100MPG]

It will heat the entire house or that part where you sit...? pretty amazing he only uses 1/16 the amount of wood he used to use!

[crazycal]

That's cool but what are you going to use as a thermal mass that won't weight 10,000 pounds?

[jlhollowx13]

I am very interested in this topic as well. I take it no one on this site has ever tried it? My wife and I manage an RV park and a customer told me about these this year. We live in a VERY cold place in the winters and our wood/coal stove leaves a bit to be desired. We recently purchased a new bus and are highly considering putting one of these in one of them, but are a little skeptical on if it will work or not. seems great, but i wouldnt want to be short on heat in the middle of the night where we live. the other issue is the weight. We bought the second bus with the intention of using it to travel while living in the other full time or at least during the winters, so the bus we put the rocket stove in will not be driven much, if at all. There are also some pretty small and light versions of rocket stoves out there as well, i think its a very customizable. i mean, my wood stove probably weighs 400+ lbs, plus the stone it sits on. I think a smaller rocket stove, made with a 30 gallon drum, maybe some asbestos insulated stove pipe surrounded by fire brick and sand, encased by a wood frame, just to keep it simple, might work in a bus. I need to do more research on the relationship between the drum size/exhaust length/exhaust pipe diameter, but i think it could be done. with the amount of wood we have used this winter we would really like to use something a little more efficient if possible.

[lornaschinske]

I think a smaller rocket stove, made with a 30 gallon drum, maybe some asbestos insulated stove pipe surrounded by fire brick and sand, encased by a wood frame, just to keep it simple, might work in a bus...

I would not use asbestos. Just me maybe but....

I think there should be a "lighter" something you could use as thermal mass. There is a Rocket Stove Mass heater on Instructables that uses lightweight vermiculite.

[jlhollowx13]

I think a smaller rocket stove, made with a 30 gallon drum, maybe some asbestos insulated stove pipe surrounded by fire brick and sand, encased by a wood frame, just to keep it simple, might work in a bus...

I would not use asbestos. Just me maybe but....

I think there should be a "lighter" something you could use as thermal mass. There is a Rocket Stove Mass heater on Instructables that uses lightweight vermiculite.

Sorry, i meant metalbestos, like the insulated wood stove pipe. might be expensive, but seems fairly lightweight and definitely well insulated. probably need some other sort of insulator around that as well though, all surrounded by some kind of wooden box maybe.

[red_zone]

I registered because I was browsing through and the rocket stove designs caught my eye... and I had some ideas to share.

The beauty of the rocket stove is that it's a totally passive heating system, but such a radiant system requires a large thermal mass to heat up, long runs of exhaust pipe for the exhaust/combustion products/smoke to transfer all of its' heat.

So, to scale down to bus-sized there may have to be two things that need to be cut - mass, especially, and exhaust duct length.
Now, the ones I've seen in all the videos have used vermiculite, clay, lots of brick, etc. Vermiculite is highly insulative, has high heat capacity, and is very light.
What you really need to store all that heat is water. Water has the highest heat capacity of any readily available material, and is the best heat storage available. This is why trombe walls in solar buildings are filled with water. Efficiently transferring the heat from the air to the water is the challenge. Luckily, this has been done; your engine does it in reverse with the radiator.

I think a small rocket stove (the 30 gal drum suggestion?) with a soapstone firebox and a radiator with a pump to circulate water into a thermal storage tank would be the best option for a skoolie. Drain your thermal mass if you're traveling for better fuel efficiency and hill climbing... if you know you're going to camp near a water source. Soapstone has the best heat capacity of most natural stone materials, equal with fire brick, and can be salvaged from broken counter tops - ask for scraps from your local custom kitchen store. This way you have 50-70lb of firebox, insulated with vermiculite for slow heat release. Water tank could be any shape - put it under your bench or under the bus (heavily insulated and with another pump for under floor heat? That'd be neat, and a way to control the heat release back into the bus. Downside? 2 pumps.)

I'd worry about over-heating more in a bus than a house, you can't move but so far away from the stove. If you drain your water and cannot refill, at least the firebox should hold at least as much heat as a cast iron woodstove.

[jlhollowx13]

I registered because I was browsing through and the rocket stove designs caught my eye... and I had some ideas to share.

The beauty of the rocket stove is that it's a totally passive heating system, but such a radiant system requires a large thermal mass to heat up, long runs of exhaust pipe for the exhaust/combustion products/smoke to transfer all of its' heat.

So, to scale down to bus-sized there may have to be two things that need to be cut - mass, especially, and exhaust duct length.
Now, the ones I've seen in all the videos have used vermiculite, clay, lots of brick, etc. Vermiculite is highly insulative, has high heat capacity, and is very light.
What you really need to store all that heat is water. Water has the highest heat capacity of any readily available material, and is the best heat storage available. This is why trombe walls in solar buildings are filled with water. Efficiently transferring the heat from the air to the water is the challenge. Luckily, this has been done; your engine does it in reverse with the radiator.

I think a small rocket stove (the 30 gal drum suggestion?) with a soapstone firebox and a radiator with a pump to circulate water into a thermal storage tank would be the best option for a skoolie. Drain your thermal mass if you're traveling for better fuel efficiency and hill climbing... if you know you're going to camp near a water source. Soapstone has the best heat capacity of most natural stone materials, equal with fire brick, and can be salvaged from broken counter tops - ask for scraps from your local custom kitchen store. This way you have 50-70lb of firebox, insulated with vermiculite for slow heat release. Water tank could be any shape - put it under your bench or under the bus (heavily insulated and with another pump for under floor heat? That'd be neat, and a way to control the heat release back into the bus. Downside? 2 pumps.)

I'd worry about over-heating more in a bus than a house, you can't move but so far away from the stove. If you drain your water and cannot refill, at least the firebox should hold at least as much heat as a cast iron woodstove.

Thanks for that input. I am seriously considering this in our 'house' bus and using our current wood stove in our traveling bus, but making it so the wood stove is removable from the side door when we arent using it/if we are traveling in the summer when it isnt needed and space and weight is more necessary (our stove is small enough to my wife and I and 1 other person can load and unload it in the bus fairly easily). We are currently looking for some land to move onto, and when this occurs our 'house' bus will probably NEVER move again, so weight wont necessarily be an issue anymore (although I would like to make it manageable so that it would be feasible in a traveling bus as well). the setup you describe sounds good, but having 2 pumps kinda kills it for me. We want to and do run on solar, and if possible have no pumps at all (we will probably need at least one for normal running water though). as far as being too hot, this could be a concern for certain regions, but where we live it is one of the coldest places in the continental US, our cast iron wood stove left a little to be desired this past winter and as much heat that is lost in these buses it may not be a bad thing to have a little more heat than needed, after all, a bus has plenty of windows to open.

for us, this past winter was VERY cold, especially at night, even with the fire cranked and we had to get up 3 to 5 times a night to keep the fire going and keep the bus warm enough. on top of it, we went through way too much wood to keep such a small space warm.

My question is this: would pumps REALLY be necessary? I mean, you can use the hot water to really pump itself if it is in a complete circuit where it will lose heat in one spot and gain it in the other, right? thus continually flowing the water and transferring the heat wherever you want it to go. also, how much water would be necessary to make this efficient? any schematics of this setup in a house type setting? maybe it would be best to put the thermal water storage up high, so that the hot water is forced up into it, then from there it can be gravity fed to a hot water tap or back into the heating system? using water was not something I had considered, so this is a new idea for me to explore.

[lornaschinske]

5 gallon bucket rocket stove

Link is just to get you thinking.