How to Make a Rocket Stove From 5 Tin Cans and Some Perlite – Infographic
Launch into a more energy-efficient way of cooking one-pot wonders
if you enjoyed this rocket stove infographic you can find and download more of these on the:
Geoff Lawton’s Masterclass Page
It’s not rocket science.
They may sound high-tech, but rocket stoves (named for the way air moves through them) are anything but.
Designed to increase fuel efficiency without increasing harmful emissions, rocket stoves are helping people become more self-sufficient, slowing climate change, and saving lives in developing countries where fuel wood is scarce and traditional open fires are polluting indoor air.
They are ideal not just because for their social and environmental benefits, but also for economic reasons: they’re cheap and easy to build, and they require very little fuel. So whether you’re looking to save money, build an affordable, portable and efficient camping stove, or just have a backup in case of emergencies, a rocket stove is a winner.
The rocket stove is a wood-burning outdoor cooking stove that was developed by Dr Larry Winiarski in the 1980s . Its as a safe, effective, environmentally conscious alternative to open fires for impoverished people in developing countries.
Compared with traditional open fires, rocket stoves can be healthier and more efficient. They reduce smoke and harmful emissions, use less fuel, and increase the amount of energy from the wood that is turned into heat energy.
How does a rocket stove work?
In open fires that are not carefully maintained, only a small percentage of the heat energy released from the burning wood makes it into the cooking pot. With a rocket stove, only the tips of the fuel wood are burned, eliminating that waste (and also eliminating smoke).
Fresh air enters the fuel chamber from beneath the burning wood resting on the grate, allowing the air to be preheated before it enters the combustion chamber, which in turn leads to cleaner combustion.
The small fuel entry not only demands less fuel wood, but also limits the amount of cold air that can get in.
The combustion itself is confined to a small, insulated space, so most of the energy in the wood is converted to heat for cooking.
The cook pot sits directly on top of the combustion chamber, so the hot gases contact it immediately after combustion, reducing smoke.
Want a rocket stove but aren’t keen on building one yourself? Don’t worry; they can be purchased. Larger, more sophisticated versions can even be used to heat a home.
If you do build your own, be sure to test it before using it for cooking by boiling a pot of water first.
That Portable Rocket Stove is soooo uber cool!
This is one of the best descriptions I’ve ever seen about tin can rocket stoves! I’ve built quite a few myself by attempting to follow directions on various websites and YouTube videos, as well as coming up with a few ideas of my own. Yours is as clear as I’ve seen, much better than most. I’m not a “Rocket Stove Scientist”, by any means and in fact have spent a lot of hours today trying to find out if my new ideas have been tried and published. I guess I feel a new rocket stove build coming up within the next few days. :)
Here are some minor points that might help improve this article.
I believe it would be helpful to have a description of the principles of successful rocket stove design as ‘defined’ by Larry Winiarski or at least a link to a website or papers on the subject. I’m not affiliated with them in any way, but here is one with a decent diagram .
Without these principles, a builder is likely to:
A) use the wrong size small cans (like so many on YouTube), thereby getting the “firebox:riser” ratio all wrong, creating an inefficient design that possibly will either not stay lit or burn fuel faster than the smoke can be combusted, among other problems;
B) use sand, gravel or rock which will act as a heat sink, instead of insulation (again, like so many on YouTube), with the resulting effects of 1)sucking heat out of the burn chamber instead of directing the heat up to the cooking vessel, and 2)causing an inefficient low temperature burn, among others;
C) let the heat out to the sides of the top of the stove, instead of directing the heat up the sides of a pan (which is part of Winiarski’s design);
and there are most likely a few more that I’m not thinking of right now.
Having Winiarski’s design priciples in mind while making the stove will help builders ensure that their rocket stove works properly. An acknowledgement that the tin can rocket stove is not as big as and therefore is not going to be as efficient as Winiarski’s recommendations, would also be beneficial.
Next, I believe you should be a little less vague on some of the parts of the diagram.
A) There are no exact dimensions given on the diagram. One gallon paint cans and #10 cans have a standard size, but without giving the dimensions, a builder might end up with a 1qt. paint can by mistake or a shorter coffee can, and then the design principles mentioned above won’t be met;
B) There is no such thing as a “regular size tin can” as called for in your diagram. Here, in the mid-western U.S.A., the most often used size found in a market (approximately 2&7/8″X4&9/16″ or 75X111mm, about 14.5-15 oz. or 398-425g ) does not provide the desired “firebox:riser” ratio, and doesn’t provide room for enough insulation (according to Winiarski’s principles), while the size of a small condensed soup can (2&5/8X4″ or 67X102mm) can do both in a #10 can or one gallon paint can — but they are much smaller diameter than Winiarski suggests for cooking;
C) It isn’t clear to me whether or not you have raised the inner cans up off the bottom of the #10 or one gallon paint can, but it definitely needs to be raised a little and insulated underneath, both to retain heat in the combustion chamber and prevent the surface on which the stove is sitting from becoming excessively hot, and I believe that should be pointed out.
D) Your use of the word “hob”… I have a pretty large reading vocabulary, but, I’m sorry, I had to go to a dictionary, only to find they haven’t defined anything like what you are mentioning. In relation to a stove, a hob is something to keep food warm, but your “circle for the hob” might mean a circle for the hole for the riser, might be the hole through which the riser protrudes, or might be the actual top of the can with the hole through which the riser protrudes, etc. Or you just might be using it as a pronoun, in which case it is taking the place of a noun, and you might just as well say a doohickey, for all the clarity it provides. There is such a thing as ‘proper terminology’, and its use makes thing clear.
E) Vermiculite and sifted wood ashes can be used with the same effect as Perlite, and I feel it should be mentioned, along with discouraging the use of sand, gravel or rock for reason’s mentioned above. Also, how big of a bag of perlite does the builder need to buy so that he can use just half of it? Obviously, that’s a rhetorical question. Bags come in all sorts of sizes. I have no idea how much “half a bag” is and neither would anyone building one of these stoves.
Lastly, you write, “Want a rocket stove but aren’t keen on building one yourself? Don’t worry; they can be purchased. Larger, more sophisticated versions can even be used to heat a home.”
A rocket stove is a STOVE, not a HEATER. A stove, such as your “rocket stove”, is for cooking on, using a vessel of some sort (pot, pan, wok, griddle etc., even a grate) to hold the food being cooked, with the secondary goal of NOT heating the surrounding air and area. A heater (such as a “rocket mass heater”) is for warming the air and surfaces inside a home, with the secondary goal of holding the temperature fairly even over long periods of time. Two completely different sets of reasons for existence.
Well, I’ve said more than enough. Like I said at the start, yours is among the best I’ve seen, but in my mind, at least, there is still room for improvement.