Rocket Heaters in Skoolies

[Seeria]

I've been considering putting a small rocket heater into my skoolie. Built by me and positioned at the rear of the bus (sitting area). I like the idea of these type heaters because I can build it myself without needing expensive materials or welding abilities; they're more fuel effecient than traditional wood fireplaces; can make them dang near any size I need; they are near smokeless. The one I would build is for immediate output of heat rather than those mass collector styles (no space for that).

Anyone else built or use a rocket heater? Have any tips? Comments? Resources?

[crazycal]

How do you keep the CO2 out.

[Seeria]

Ah sorry, guess I should have done some links. Listed some below.

Basically, the way it burns reduces the amount of emissions and uses fuel far more efficiently than traditional wood burners.

Several designs for them, some used to heat rapidly for small areas, some to heat entire houses, heat water, or as a cook stove. Some links

http://www.richsoil.com/rocket-stove-mass-heater.jsp
http://www.aprovecho.org/lab/index.php
http://www.aprovecho.org/lab/pubs/arcpubs
http://blackearthrocketstoves.blogspot.com/
http://en.wikipedia.org/wiki/Justa_Stove
http://www.stovetec.net/us/index.php
http://solarcooking.wikia.com/wiki/Rocket_Stove

I own a mini-size camping stove that is based on the rocket stove principle and find it works wonderfully, so am working on making one a bit larger to use in the skoolie that has more "rocket" design to remove the emissions and smoke.
Not sure what design to use to the heater, though, thus looking for ideas.

[crazycal]

so am working on making one a bit larger to use in the skoolie that has more "rocket" design to remove the emissions and smoke.

The only way to safely remove those emissions is to have them go up the chimney.

[Seeria]

There will be a chimney, and probably an additional air intake like some of the plans show on YT vids and the publications linked. That would do away with any left over from the high combustion, and make it a tad bit safer on the air consumption. Though, not overly worried there since I'd never stay in a RV, bus, whatever without windows cracked. Darn condensation.

Since it seems to be a new idea here... anyone have links or tips to setting up the flooring, backing, etc for a wood stove-heater, pictures of it done in their own bus?

[crazycal]

I would think you could use cement board. I have bought some at HD before. Looks at Smitty's pics, he has a nice wood stove he built. He used corrugated steel around his stove.

[Stuff]

very interesting idea! works well to if the zombie apocalypse happens

[Redbear]

I hadn't heard of these, either. At first glance they remind me of a "Russian Fireplace," where the smoke goes up and then down in the masonry, and then goes through a floor-warming masonry channel under the floor before going up a chimney opposite the fireplace. I understand there is an art to their construction, as getting them to draw properly can be tricky. (Probably like setting up the draft behind a propane fridge!)

The Finns make a line of soapstone wood stoves and fireplaces based on this principle. They are beautiful, and they are not inexpensive. They also use the thermal mass of the stone, so they claim a handful of kindling provides slow heat for 12 to 24 hours, if I recall correctly:

http://www.tulikivi.com/www/TLTuoteU...auunit&id2=TA1

Both do require a tall vertical stack at the end of the horizontal section to get the draft flowing properly. I can understand how the rocket chamber could sustain a horizontal side draft once it was started, but can't wrap my head around how it would start one. I admit I just took a quick peek at the photos and diagrams in a couple of the links, and have not yet read in depth to find what physics are at play or how you use one.

[lornaschinske]

I have to agree with Smitty on the fuel usage. I think they are either using a huge thermal mass (can't do that in a moving vehicle), they are in mild weather or they don't mind being a tad cooler than I would (I dislike cold). Too much thermal mass means too much weight to be moving around. Anything you save in fuel heating costs will be used up quickly in fuel moving costs. Diesel is $3 per gal and that's on the Reservation where gasoline is 21 to 30 cents per gallon lower than in Socorro & ABQ. Diesel seems to not be lower priced by much but the truckers are lined up there to refuel.

IF I were going to be putting in a solid fuel heat plant (which I'm not... just the mantle! ) I would opt for one of the small multi-fuel stoves or a good small airtight wood stove WITH A BLOWER FAN. If you are going to be traveling around, you will not know what type of fuel or how much is available. And if you plan on staying in public lands, they have limits on how much wood you can bring in as well as what type and from where (bugs!). Out here in Socorro, NM, where a tree in a campground seems to be rare... they sell bags of the pellets for the pellet stoves (didn't see much of that stuff back in the Nantahala & Cherokee Forests) and we have also been told that you can pick up "downed" wood for FREE FREE FREE "on the other side of the mountain" which is BLM land (just need something to cut it up with and to transport it in). There is so much that folks will load up huge truckloads and sell it on the street. Seems to be mostly red cedar from what I can tell (and smells heavenly). In a private campground, they usually don't want to see huge stacks of wood next to your RV (and certainly not exposed!).

WARNING... Long, drawn out ramble....
We used to heat a poorly insulated 2 bed house with a mid-sized airtight Appalachian brand stove (it was this size and yes it did burn for a very long time on hardwood). http://www.appalachianstove.com/woodstove_30CD.php I would stoke it at night before we went to bed with about 4 or 5 pieces of split oak, bring the fire up real hot and shut the damper and vents down. Then about 5 in the morning, I would go to the bathroom and add wood & open up the vents a little to boost the heat so we could get ready for work. We were up by 7 and before leaving to work in town I redid my nightly fill (I was gone about 11 to 12 hours because I worked a 9 hour shift at the factory). By the time I got home the house was still warm. And I would just toss one or two chunks of wood in the rest of the evening. We had built a "L" shaped brick wall and placed the wood stove in at an angle on a raised hearth.. the stack was exposed until it when thru the ceiling into a triple wall pipe and spark arrester cap. It had a blower unit on it (definitely recommend a blower) to circulate the warm air thru the house. We had an LP gas furnace as a backup and it never kicked on not once... except when we when to FL for a week over Christmas one year. That was the second wood stove we owned. The first was a cheap Ben Franklin type that LOVED to eat wood. Hey, it was $25. Our second stove was used and cost us $300. When we moved down to SC, we sold the 12 lb monster maul (what I used to split wood with) along with the Wood stove, the salvaged triple wall pipe sections and cap (our house had burned down a few years before... electrical fire... turned out the house had been wired by a drunk and we didn't find all the bare live wires inside the walls). I told David I wasn't going to split wood anymore. So that put an end to wood stoves and fireplaces for me! Besides, it took me years to get over feeling a little sick when I smelled wood smoke. Now I usually enjoy the smell but not like I used to. Still at times it reminds me of watching almost everything we owned going up in flames.

[Ob1]

My converted bread truck came with a real deal propane RV furnace, sealed burn chamber, air intake contained within the exhaust, 120VAC/12VDC blower.

Once I cleaned all the mud dauber nests out of the burn chamber, it works fine. My only complaint it the place where the original builder put it; towards the back of the vehicle by my bed, the Aft Stateroom. I like to sleep a bit cool, and it wants to run me out of there, while the front area runs cool.

Heats well, the blower is a bit anemic though. If you find one, be sure to place it in a central location. If I ever redesign my layout, a central location and maybe some inventive mods to move the heat around will be in order.

[lornaschinske]

Originally Posted by Ob1

... Heats well, the blower is a bit anemic though. If you find one, be sure to place it in a central location. If I ever redesign my layout, a central location and maybe some inventive mods to move the heat around will be in order.

Ductwork! When we remodeled the Class C we had to remove a couple of vents. We built a plenum out of flashing and now instead of vents out the sides, it vents at the front (into the galley) and out the side (next tot he front door and the front living area. I also put in a new thermostat. Works great... when we run it. We usually run the little electric heater if we have the electric included with the site rental... which we currently do.

[Seeria]

The interest in these LOW mass rocket stoves for me is primarily their low fuel consumption. Even the little can models that weigh next to nothing (the low mass ones) use far less wood due to the design. Finding "legal" wood to burn while on the road that doesn't cost me is rather hard from my past experiences, so fuel consumption vs heat output is important. Hope that helps

[Redbear]

Well, I took another look this past week, and downloaded the Aprovecho labs .pdf. It appears there is a vertical stack at the end of the horizontal pipe heating the mass of the bench. Some of the incomplete construction pictures I first saw made it appear that the flue emptied horizontally into the room. So it appears the rocket stove fire is undamped, and the accelerated airflow gives a blowtorch-type fire heating up the storage mass. I would think the hotter fire would burn shorter, not longer as '87-IH supposes, with the mass then storing and releasing the heat. This is certainly like the Russian/Finnish masonry stove designs. These definitely deserve a look, but space in a skoolie may limit construction options. Most big buses should probably be able to handle the weight, depending on how much water or engine fuel is intended to be carried.

[lornaschinske]

I would say that you need to mock up a semi or full working prototype. Often that is the only what you can see if something will work. Do it outside of the bus, following the same criteria and space constraints as if it was inside the bus.

[tomas_maly]

I would love to have an efficient woodstove situation in my bus. I think the nature of a rocket stove is that the flue follows along some sort of bench, etc or something with a lot of mass (ie solid clay/cob) so heat gets stored and radiates over time. I think the second half of the rocket stove is trying to keep it to run at a lower temperature, which may involve controlling/minimizing air flow and the size of the box. I do know that part of the equation is how the fuel (ie wood) is fed, through a smaller vertical shaft, shaped like a U, where the fire burns on the left side of the U and the wood slowly gets burned/pulled down on the right side of the U. I could be wrong, I've only seen a demo once.

I do know that it's common to put barrels on top of the fancy duct work (ie up and back down), which should provide a cooking surface.

There's an interesting book on "rocket mass heaters" by Ianto Evans, which may be good for a design standpoint. As for general woodstove design/DIY, there's a book "Wood Stoves: How to Make and Use Them" by Ole Wik, which goes into several varying designs. Since I've never done any before, I'd either get a used woodstove one at first, or spend several months designing and prototyping in/near my garage. The tricker part of a rocket heater is that they traditionally involve lots of brick/clay to

There is a prototype 'super efficient' stove out there called the 'Kimberly', but the owners of the company has quoted me something like $4,000 . I'd rather spend a month or two and design something myself and then share the plans online.

[Jellyfungi1987]

4000+ ibs yeah right

[BowserJournal]

I have used rocket stoves to cook in my backyard and such. I have never gave it much thought to use to heat a bus.. Have you done this yet?

[Jellyfungi1987]

I made a cob oven last year. It's not very big like 3' x 3' and its is extremely heavy. Iam looking for a way to heat my bus at the moment. I want a wood stove that's not to large.

[jrtroubleshooter]

I had a homemade 30 gal oil one that I made with 12x28 talipa greenhouse.

It worked ok. I do not think good app.

They burn fast and hot, if you have mass to hold that heat this is good. Most busses loses heat fast and unless you parked mass is a problem.

I am going to try a cabeles thin sheet metal stove this winter in upstate NY when working on conversion.

I think it is this one.

Cabela's Sheepherder's Alaskan Stove : Cabela's

[Tango]

The rocket concept works best when combined with lots of heat retaining mass. Mass = weight. Might be tricky in bus but worth examining.