The principles of a rocket stove and how to build one.

[chefgiovanni]

We just built a wood fired pizza oven out of recycled materials and pizza stones, click on my name and check it out on the site. Chef Depot . c o m find the pizza section page 5 !

[keptyeti]

How do you clean it out?

[starman2765]

@keptyeti Most of the combustible material is burned off. That is the beauty of the rocket stove. Check out Ianto Evans book Rocket mass heaters for more information.

[scott98390]

That is one bad hat, Harry.  :-)

[Rockinghorseshart]

@scott98390 , I think that hat could be an excellent source of biomass for use in a rocket stove.

[starman2765]

@Rockinghorseshart some people use sunflower stalks for the biomass.

[Rockinghorseshart]

starman, thanx 4 the reply! Yes I know (though I was thinking about saving u the embarassment of wearing it! lol! sorry!) re: this biomass source- I've wondered if it is actually better 2 plough it in to the soil? I visited ur video as I intend 2 build a water heater to supplement my gas central heating in a utility room connected to my house. I am trying to think how i can use the J stove in a more upright position (for compactness) whilst still benefitting from the design. BW, RHS

[starman2765]

@Rockinghorseshart the rocket stove will give off a little smoke into the house. It's important to realize that before installing it. If the utility area you mention is like a screen porch, then it may be appropriate to put the rocket stove there. Not a lot of smoke; just a little as the fire gets started. As for alternative designs; I'm not so sure. The main thing about the 55 gallon drum is it won't burn. Something smaller but still hardy might work for you.

[Rockinghorseshart]

@starman2765 TY again. Here in the UK the inclement weather means my stove will be indoors with a chimney of at least 60cm height. I will fire the stove with discarded wood (there's a seemingly infinite supply of this in populated areas). The central heating radiator hot water will be diverted from the gas heating system and preheated, then heated as it passes thru' the J stove and returned to the house. Best Wishes, RHS.

[starman2765]

@Rockinghorseshart let me know how it turns out!

[chrismallyon]

The only question i have, is how the heck you clean out the ashes when your done?

[starman2765]

@chrismallyon Most of the combustible material is burned off. That is the beauty of the rocket stove. Check out Ianto Evans book Rocket mass heaters for more information.

[amos033]

Mexicans have been building rocket stoves for over a 1000 years. They call it a 'cheminia' made of clay. They made them of clay - look them up - identical technology.

[starman2765]

@amos033 Fascinating how these sorts of technologies emerged at about the same time in different continents. Thanks for the comment.

[Organikmechanic]

Great vid. I like the idea and its well explained. Got to try for myself now.

[myastroflight]

They were far from smokeless. Not suitable for indoors at all.

[MisterBahston]

Now all we need is the US government to stop squashing self sustaining heat / energy production because THEY cant profit off it.

And we need them to also reinstate legal growth of cannabis ruderalis (hemp) so that we can have rapidly replenishable solid fuel source without the need for deforesting.. -- dont hold your breath.

Great stove! Great educational!

[starman2765]

@MisterBahston thanks for you thoughts!

[muserwood]

Do you put a concrete cover over the cob ?

[starman2765]

@muserwood if can do that. I'd go more with fire bricks; and just plain cob. The cob will be fine.

[Anvilshock]

Uh, question. How do you get the ash out of this thing after a run? Do you just poke around in it with an awkwardly bent rake and then reach into the feeding hole with your hand? This looks somewhat like a design flaw. :/

[starman2765]

@Anvilshock Ash builds up very slowly if at all. There is almost no ash created at temperatures above 1500 degrees; and that's how hot it gets in the burn chamber.

[jtcweb1]

Are you going to be doing a demo in S.E. MI again sometime?

[skywriter1962]

you forgot the chicken wire step! What is under the chicken wire?...it don't look like bricks?

[DCVU2]

I have 25 fb2 firebricks, and many old solid red bricks. Can I build a rocket stove mass heater with this, or must I buy more firebrick?

[starman2765]

@DCVU2 This depends on the size of the barrel that you are using. Fire bricks don't break up due to repeated exposure to heat; and they tend to store and release the heat better than regular bricks. The combustion chamber gets very hot! I've recommended Ianto Evans book before, and I recommend it again. Thanks for asking.

[DCVU2]

@starman2765 I've got that book, it doesn't solve everything. Thanks anyway.

[starman2765]

@DCVU2 All I can suggest is trial and error; and be safe! We used non-fire bricks that were a distance from the fire. The fire bricks will retain their shape, and release heat into the space. They are ideal for the application.

[DCVU2]

I have 25 fb2 firebricks, and many old solid red bricks. Can I build a rocket stove with this, or must I buy more firebrick?

[MrSafetymeeting]

I am trying to figure out how to mak one for a housebus. Its a small cabin that moves from time to time so I don't know if fire bricks are going to work. I was thinking of something like the rocket stoves people cook on with the barrel riser set up over that. I would use heavy steel pipe for the burn area, feed pipe,riser pipe all welded with vermiculite insulation and surrounded by bricks for thermal mass. Any thoughts?

[starman2765]

@MrSafetymeeting There will be some minimal smoke that gets into the space where the feed for the rocket stove is located. I'd put that outside on the tailgate of the vehicle. As for the plan you mention, that sounds fine. I'd love to see picture or video of it when you are done. Best wishes!

[MrSafetymeeting]

@starman2765 Smoke? I figured the draw would handle most of that but I will definitely consider this. I actually have a porch but the intended position of the stove is 6 feet from there. My concerns were the draw eating up my air. Thinking of a Y where I could bring in outside air. The main concern is many of the materials are heavy and brittle. I'm assuming all appropriate thermal mass material is heavy . I will post something when I finish and I thank you for your response.

[starman2765]

@MrSafetymeeting The draw does handle most of it. There will be a little smoke that comes out from the first few twigs that are used to start each fire.

[Rauschelesee]

@MrSafetymeeting

Please can you help me. Whats are the name from this "rocket stove mass heater" in German? Thank`s Martin

[starman2765]

@Rauschelesee I'm not sure that there is a good translation. The best I found was: Rocket Stove Masse Heizung. I hope that this helps.

[Anvilshock]

@Rauschelesee Most (bricked) ovens for heating are designed to have a good draft and use of flue gas' heat well (compare Kachelofen), so "Raketen-" would be kinda redundant. If you want to underline the special J shape combustor in German, you might want to say just that instead.

"mass heater" simply describes what the German word "Wärmespeicher" is common for. One translation attempt would be "(Selbstbau-) (Raketen- oder J-Rohr-) Ofen mit Wärmespeicher". Beautifully technical German, i'nit? ;)

[Frankenlego]

RE: why doesn't the smoke/heat go out the firebox vs sideways and up the heat riser? this is how I see it:

Ever siphoned gas out of a car? stick in a hose, drop the outer end below the surface of the liquid, apply vacuum and let gravity take over (gravity creates a vacuum which keeps the siphon in effect)

now, flip it upside-down, the 'hose' is now above the surface of the "gas", reverse-gravity in this case is 'heat rises'. The heat rising creates a vacuum which keeps the siphon in effect

[starman2765]

@Frankenlego That's right. The heat rising creates a forceful vacuum that draws the smoke into the barrel where the smoke burns, leaving no ash.

[weaubleaumo]

Thanks for the effort expended in this video. Diagrams- common sense explanations and lessons learned ( barrel paint burned off BEFORE installation =D ) and great camera work ( NO VERTIGO ! )  Excellent resource guys!

[Dolichocephalus]

is there something else I could use instead of vermiculite for insulation? Would ashes and sand do the trick?

[starman2765]

@Dolichocephalus just don't use any thing that is flammable. If there are any unburned bits mixed in with the ash, they likely would catch fire, as the stove reaches very high temperatures. The vermiculite is volcanic and so very heat resistant as well as being ideally suited to dispersing high heat. Ash and sand would work, and could do a very good job of it too.

[petthekittyz]

@Dolichocephalus perelite is usually cheaper, and its about the same thing

[Wazabooz]

So am I correct in saying the barrel radiates heat into the living space, and the piped out exhaust supplies heat to a thermal mass (like the seat in the photo)?

[starman2765]

@Wazabooz That's right :)

[starman2765]

@Wazabooz That's right.

[jmg1957]

nice.

[starman2765]

They should last a long time; just keep them dry: indoors, with a tarp or whatever. They are much more efficient than regular chimney stoves. I've recommended a book by Ianto Evans, and recommend it again. Just google rocket stove, Ianto Evans to find it. Or check at your library.

[brucebrucelois]

What 's the life span of these stoves, and are there any problems with creosote build-up? Are they the same, or more effective with fuel consumption and heat output than a masonary heater?

[assym2006]

do rocket stoves use less fuel{wood{ than a normal fire place to heat the same square area please ?

[starman2765]

Yes they do, significantly so.

[starman2765]

Much less wood.

[assym2006]

@starman2765 thanks , I am like the look of these more and more.

[parryaj72ss]

How long does it take for the barrel to burn out?

[starman2765]

Please refer to Ianto Evans book Rocket mass heater for more information.

[PedyCoober]

But how can I get "sand dug out of the ground in Michegan" when I live in Texas?

[starman2765]

You can buy sand at a store; or perhaps a neighbor has access to some.

[WoodBClayMaster]

My question is, first how do you clean out the barrel, since over time it will collect residue that in itself will be combustible & two, could you use refractory brick & clay tile, to better make the combustion chamber?

[starman2765]

Most of the combustible material is burned off. That is the beauty of the rocket stove. Check out Ianto Evans book Rocket mass heaters for more information.

[Soldier957]

Looks interesting but does it meet the firecodes for indoor operation?

[starman2765]

You'll have to check with your local government agency.

[HISandman]

I love this idea but how does the smoke from the fire take the path of "Most" resistance rather than out the feed tube?

[starman2765]

The draft is caused by the intense heat and vacuum thereof. At first some smoke comes out the lighting chamber; but then it is funneled through the exhaust tube. Build one, or visit one to see what I mean.

[1jks]

What chances is there of a chimney fire occurring? How do you clean out the creosote build up in a enclosed system like this where everything is built up all around it?

[starman2765]

Check out the book by Ianto Evans Rocket Mass Heater for detailed information to questions like these. The principle interviewee in this video has lived through 3 severe Michigan winters without having to clean out the chimney. The Creosote is almost completely burned away in the combustion chamber before it reaches the chimney.

[Spugeli]

Almost like the Sauna. :)

[neoplasticity]

why doesn't the smoke just go straight up? how do you get it to go sideways into the combustion chamber? seems like it would be much more likely to suck in air from the combustion chamber and blow smoke straight up into the room.

[starman2765]

When you first light the stove, some smoke goes into the room; then when there is sufficient heat the smoke is drawn along with the hot air into the combustion chamber. The best way to deal with this is to encase the area where the fire is lit, rather like a traditional fireplace has a screen on it for the same reason; or to put the part of the stove where it is lit outside. It doesn't take long for the heat to drawn all the smoke into the combustion area.

[starman2765]

The smoke is drawn into the combustion chamber by the vacuum created by burning creosote. Please refer to Ianto Evans book Rocket mass heater for more information.

[Naanoux]

Could the "ugly" barrel be covered for more thermal mass ?

[starman2765]

That could be done with something that won't catch on fire. The barrel gets very hot too.

[pumoo]

good

[bwpenoyer]

That's kinda cool!!!

[starman2765]

For more information google Ianto Evans Rocket Stove.  He has a great book on the subject!

[johnjmw1]

Loved the presentation. I've been looking at building one of these for a few years now. It's good to see the information getting out to the general public in an understandable format.

[pudnhead41]

Excellent! Quality work! And a dashing fellow in the straw hat;) Question:In an indoor setting, does the smoke at the initial lighting going into the living space?

[oediVideo2]

This is a well thought out video.......I was at the Energy Fair in Manistee where this was made and the crowd got quite large, which doesn't show in the video. Good job!

[rogeliomarigomen]

hi, nice work. how do you remove the ash which accumulates after a while ?

[starman2765]

Using a suction device as a vacuum cleaner; the other way I'm aware of is to put removable bricks in the design.