Rocket Stove Mass Heater

[awoodman]

I came across this term (Rocket Stove) last week and it is undoubtledly a super eficient wood burning technoligy.

http://ilovecob.com/gallery/rocketstove/
http://ilovecob.com/gallery/solunit-rocket/
http://www.chilakootbowhunters.org/cooker.htm
http://www.permies.com/bb/index.php?board=10.0

 

[daleeper]

I have studied some of these sites, and like some of the concepts, not unlike a masonry stove. However, I just could not install anything that has an open flame like that. I guess it is not a whole lot different than an open fireplace, but I don't have one of them either.

 

[awoodman]

These stoves are revolutionary yet soooo simple. Suitable for straw-bail or ICF type homes where THERMAL-MASS is what keeps the house temp. constant. This is where modern home construction falls short. So the result is wood consumption in my stove and just about every one on this forum.

I am a cabinet maker and have my own shop I see these hundreds of thousand $ homes go up and still making the same mistake(inefficiency). The builder I supply I have told (give the people what they need not what they want). :lol:

 

[daleeper]

These stoves are revolutionary yet soooo simple. Suitable for straw-bail or ICF type homes where THERMAL-MASS is what keeps the house temp. constant. This is where modern home construction falls short. So the result is wood consumption in my stove and just about every one on this forum.

I am a cabinet maker and have my own shop I see these hundreds of thousand $ homes go up and still making the same mistake(inefficiency). The builder I supply I have told (give the people what they need not what they want). :lol:

The concept is simple, but I really don't think proper implementation is any simpler than a common wood stove. A wood stove and chimney really is not all that complex, yet the implementation of that system from one space and climate to another is what makes this forum fun and helpful. You hit it on the head when you said that most new construction does not take into consideration efficient use of resources, including design of the home around heating/cooling needs. Heating and cooling a home efficiently and comfortably can be more complex than some may want to admit. It also takes resources and compromises that most don't want to allocate.

Don't expect too many folks here to get real excited about these Rocket Stoves.

 

[awoodman]

Most of the people in the USA are oblivious to what is going on outside their own (comfort zone).

Now that said...........

Half of humanity cooks over wood fires -- the poorer half. Nearly half the world's wood supply is used as fuel.

But it's not enough -- more than 2 billion people are facing fuelwood shortages. Forests in the developing countries are shrinking by more than 15 million hectares a year. The ratio of forests-to-people is less than half what it was in 1960.
For most, there's little alternative to burning wood -- wood energy is here to stay.

In fact burning wood is no bad thing: the efficient use of wood fuel is much more eco-friendly than more efficient and convenient fuels like kerosene and natural gas (LPG). LPG emits 15 times more CO2 (carbon dioxide) per kg than wood, and kerosene nearly 10 times as much. CO2 is the main source of global warming.
http://journeytoforever.org/at_woodfire.html

(bump this post up so more people become aware)

 

[awoodman]

Maby I have this post in the wrong catagory?

 

[Todd]

CO2 is the main source of global warming.

BS! Biggest scam of our time!

 

[begreen]

I remember reading up on the experiments with this stove design a couple years ago. It takes some skill to build one that works well and drafts properly at all stages. Still, when working, they make great bench warmers.

 

[Nonprophet]

I run a small nonprofit that builds Rocket cooking stoves all over the world. They are very simple, yet very efficient stoves. Their main advantages are that they are very inexpensive to build, designed properly they produce very little smoke (there are serious health issues for women and children in the 3rd world from breathing in wood smoke from daily cooking) and thus don't need chimneys, and, they limit deforestation by using underutilized resources for fuel (like sticks/twigs, coconut husks, etc.) It's pretty amazing to cook a meal for 5 people using a handful of sticks that would otherwise rot on the forest floor.....

While a Rocket stove heater isn't practical for our yurt (weight issues) we will be building a cob home this coming year and we'll definitely install a Rocket stove mass heater in our cob building. We have two very good friends who use one in their cob home, and it's really amazing how much heat these stoves put out for such a minimal amount of wood--plus they produce virtually no smoke at all. Add to that the fact that you can build one for about $100, pretty cool stuff. I'm thinking that I would like to incorporate a gravity/self-feeder design into ours where splits would be stacked in a chamber and fed automatically into the fire once their predecessors are burned. The would be a grate that would stop the splits from self-loading when desired.

Gotta love appropriate technology


NP

 

[awoodman]

If I were to build one the gravity feed would be my choice. To bad I didn't know about these 7 years ago when I was building my house. This is what I use to heat 2000 sq. foot.

 

[awoodman]

Another Rocket Mass Heater site.
Rocket Stoves.. Experimenters corner.. Answers questioned!
Just do a search for ( donkey32.proboards )

..............................................................................................
rocket/bell project:

I have spent a lot of my spare time trying to simplify the rocket syphon. In fact, the majority of my experiments has been in vain: at the moment I'm back to square one, more or less.
In an attempt to make a very compact layout I've been testing a rocket syphon on top of the firebox. No good at all, it refused to work properly, whatever layout didn't matter. Two months down the drain and no results until two weeks ago.

The syphon at the moment is made of refractory concrete, very thin-walled at one inch. The riser is short, twice the main opening plus a burn tunnel of one inch. Main opening is 4" by 8".
The riser is made of vermiculite board and is heated up in a very short time. As visible in the drawing, the air pipes are not just in front of the main mouth but 4 inches away from it.
Two weeks ago I started with optimizing the burn. The results are very encouraging: the thing is running better now with less wood than last October. The pipes inside the firebox are lengthened with a piece that's running back to the door at the same wall. The horizontal piece has a thin slit of about 1/8" x 5 1/2".
The slit is about half the surface area as the inside of the pipe. With minimal air fed through the loading door this runs remarkably well.

For performance, see graph:
http://www.pberg.demon.nl/pictures/large/test090516.gif
Exhaust temp is in Celsius, highest point 212 F.

I've tried to take pictures of a burning stove, but that's only disappointing. Last week I've got a new camera which is capable of taking short films. Two of that I've uploaded to YouTube. The first is of the stove burning just before the height of the run. The flames which are blowing away from the pipes can be clearly seen.
The second is at the end of the test-run after the second refill. The mouth of the syphon is a lighter orange than the firebox walls itself.
Highest temperature just behind the second vertical wall of the syphon during the run: 1790 Fahrenheit. In fact, it's not the spot with the highest temp of the whole contraption. But the sensor is only capable of measuring up to 1830 F. Any higher and the thing will die quietly.
Next goal: upscaling to 1.7 times and using the mantle and door of a commercial Bergkachel version.

 

[awoodman]

This guy's stove is ausome................another post from that forum.........
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Re: rocket/bell project
« Reply #10 on Nov 15, 2009, 1:40pm »

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Today, another test run has been performed. Air intake has been altered slightly, starting up problems has finally been overcome.

In fact, the firebox is loaded up to the edge of throat, with some kindling on top. As close to the syphon as possible. The kindling is lit and the regular air inlet closed and the loading door open for as much as about half system size. After about 10 to 15 minutes the syphon is warming up sufficiently, the rocket roar is starting to be very audible. The door is closed at that point, air inlet open slightly, something like a quarter system size.
The performance of the stove has been impeccably after that.

Moreover, refilling has been problematic up till now because shortly after that the CO would rise to a high peak, sometimes beyond the capacity of the Testo. Today's run was very successful in the sense that now the CO will rise slightly after refill. In 2 minutes or less the CO will go down again, sharply. To a level of less than 100 ppm, O2 level down to 7.8% at the same time. And only water vapor to be seen from the top of the chimney.

I'd call the results very good for this run. I am very happy, the thing is stable at last! A year ago I've said "I've got a dragon by its tail" and now I finally know the size of the dragon!

 

[awoodman]

More info ..........
http:// donkey32.proboards.com /index.cgi?board=experiment&action=display&thread=113&page=2
http:// donkey32.proboards.com/index.cgi?board=experiment
First rocket/bell PD drawing is ready.

This one do contain all the results of development so far.
I've decided to release in stages: the heart of the thing first, next with the first bell around it, etc.

Of course the picture above isn't the drawing, that's just a jpeg image. The real 3D-picture is here: http://www.pberg.demon.nl/pictures/PD/RB-PD1.skp
The format is Google's SketchUp, version 7, this is a free 3D drawing program.
In order to view and manipulate the drawing, download the program here:http://sketchup.google.com/download/gsu.html

Tonight, I've found out that some links do point to the wrong location. The download will be version 6 in a number of occasions, so I've uploaded the executable of version 7.1 to my own website, just for now.
http://www.pberg.demon.nl/pictures/PD/GoogleSketchUpWEN.exe

The drawing itself is organized in layers, every row of bricks forms one, more or less. It's perfectly possible to take it apart with the SketchUp tool "Move/copy". Select the tool, select a brick and move the layer away. In order to view all around it, press the scrollwheel or middle button and move the mouse.
Once you're familiar with it, it's a great toy.

About the stove: this one is more or less complete to build a bell around it. The firebox is there, and so is the syphon and the first upstream channel. Just in case anyone would like to build the thing with a single bell, please do omit the upstream channel. The bricks represent one with the dimensions 8"x4"x2". SketchUp do have a tool to check dimensions.
« Last Edit: Dec 26, 2009, 2:21pm by peterberg »

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Re: rocket/bell project
« Reply #29 Yesterday at 5:33am »

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During this week the updates will following close behind each other... This update can be found here: http://www.pberg.demon.nl/pictures/PD/RB-PD1a.skp

The lowest region has been changed: the horizontal side-airducts are repositioned 4" higher up. Consequently, they will be closer to the fire and warm up quick.
The floor of the firebox do consist of replaceable firebricks. To this end, they are not glued together in any way.

So, it's possible to replace the airducts without dismantling the stove in its entirety.

 

[karri0n]

I think these are great for small buildings such as camps, yurts or huts, and definitely better than using an open flame in the living space for cooking like is done in much of the world. For modern, well-sealed, contemporary construction in first-world countries, I would prefer something like a masonry heater that vents outside. The No chimney thing gives me the heebie jeebies. In a house that has a hole in the top because cooking is normally done over an open pit, it's a very different story.

 

[cycloxer]

Very cool what you can do with wood burning.

 

[myzamboni]

Very cool what you can do with wood burning.

yeah: %-P

 

[yeshuaschosen]

Here is a link if anyones interested in making a rocketstove pizza oven!
http://woodfiredpizza.org/Rocket/index.html

 

[wkpoor]

On this site I can't believe nobody said anything about not being EPA approved.

 

[pen]

Thread's from 2009.