The Amazing Rocket Stove

I just built a Rocket Stove out of 3 tin cans and tested it by making my morning coffee:

My 10 year old son then followed up by frying an egg. Each time we used a tiny amount of fuel; a bit of cardboard to get it started and maybe two sticks 1cm wide by 10cm long, weighing a few grammes:

Rocket stoves are very efficient as they burn the fuel at high temperature. You can see some ash between the inner and outer cans above which insulates the combustion chamber. Air flows under the tray in the magazine which is preheated before combustion. They can be built in a variety of sizes. Mine used a small paint tin as the outer container and is big enough for a coffee pot or small fry pan. A larger one (say using a 5 litre oil can) could handle a families cooking.

I am interested in Rocket Stoves for a couple of reasons:

  1. On our recent trip to East Timor, I noticed most people cooking on 3 stone fires. This is causing environmental (and practical) problems as vast amount of firewood are being used up. The cost of the wood fuel is also significant for people in one of the poorest countries in Asia. So an efficient wood stove could really help. Rockets Stoves can be built out of locally sourced materials (old tin cans, bricks) and could generate much needed employment.
  2. I am interested in heating my house from wood this winter, but don’t want to pay $3,000 for a commercial slow combustion wood heater. So this little stove is a first step. I have seen some heating stove designs that use bricks and old drums to make efficient radiant heaters.
  3. I am interested in alternatives to fossil fuels like natural gas for cooking. Over the last few years we have been taking steps to improve our home energy efficiency and in particular reduce fossil fuel consumption. Our last gas bill was trivial ($12 gas, $50 supply charge) as we have solar hot water. The low fuel consumption of a Rocket Stove means we could supplement our household cooking with fuel from garden waste, e.g. sticks and other garden material I usually throw out!

It took me three tries to get a working stove; I spent a pleasant Saturday afternoon messing around with tin snips and tin cans and like everyone I love playing with fire! My Rocket Stove takes a little while to start burning well, but once it does you get a small, very stable flame. Almost like a gas stove, but coming from one little stick. It’s easy to control, just slide the sticks in or out of the magazine.

Links

I used the tin can Rocket Stove example in this Capturing Heat booklet.

6 thoughts on “The Amazing Rocket Stove”

  1. Dear David
    From time to time I take a look at your website. This week I found that you, also, have developed interest in stoves. I just want to comment that there is a project in El Salvador which is building efficients stoves.

    http://www.latimes.com/business/la-fi-stoveguy28nov28,0,2014432.story?coll=la-home-business

    I think they have an important technical problem—The need to power a small electrical fan—to solve. I hope they will came out with a solution

  2. Thanks Carlos, that was an interesting article. I think the investor should just open source his invention.

  3. Dear David
    As I understand the salvadorean inventor wanted to develop an industry here in the country. By the 1st of June, there is going to be a new goverment which, he dreams, can support the project of exporting those stoves. Reading the news, I found the following article

    http://www.nytimes.com/2009/04/16/science/earth/16degrees.html?ref=earth

    The idea of “adding a small fan that improves combustion” is being tested. We will see if that solution helps the efficiency of the stoves.

    Wishes,
    Carlos

  4. Google bioenergylists for gasifying and fuel efficient woodstove designs.

    In particular stoves.bioenergylists.org have a big range of designs including TLUD (top lift updraft) gasifier stove by Reed/Larson.

    I fail to see how an oxygen starved slow combustion heater can efficiently pyrolyse and combust all the fuel without putting soot and creosote up the chimney. Fast, hot stoichiometric burns are what you need.

    Thought about a masonry stove aka kacheloven aka tulikivi?

    Also http://www.stove.ru is worth a look for how one Russian likes to do it, modelled on the heating/cooking/fuel efficiency work of Podgorodnik in the 1930s.

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