With the help of our summer interns, we built our first rocket stove for use in the village a little over a month ago. A rocket stove is a more efficient way of cooking with fire. It uses smaller diameter wood — and less of it — but still cooks faster than a traditional open fire.
A rocket stove is incredibly easy to construct, and it can be made entirely out of materials already present in rural areas.
Parts of a Rocket Stove
- Chimney: the vertical hollow space on which the cooking pot rests and through which heat passes to escape
- Fuel Magazine: the horizontal hollow space through which a) fuel and b) air travel into the combustion chamber
- Fuel Shelf: a metal shelf in the fuel magazine on top of which fuel is placed and under which air flows
- Combustion Chamber: where the fire burns; also where the fuel magazine and chimney meet
- Heat Exchanger: some device which forces heat from the chimney to pass over the sides of the cooking pot
We use cob to build our rocket stoves, as all the ingredients are readily available in every village. Cob is also fireproof and easy to repair. Sorry I didn’t get any photos of us actually placing the cob on the banana stalk frame. But I’m sure you understand the process.
Probably my favorite advantage of the rocket stove is how little fuel it requires. Deforestation is a big problem in our part of Sukuma land, and much of this is due to charcoal-making and firewood supply. Rocket stoves allow families to harvest fallen and cut branches, rather than entire trees. [I'm wanting to encourage families to begin coppicing (planting an area of fuel-providing trees which regrow limbs quickly after being cut).]
Many manufactured rocket stoves use a tubular sheet of metal as a heat exchanger. It sits on top of the chimney, circling the pot, in order to force heat to remain in contact with the pot. [I'm not sure if they're really called "skirts," but that's what I call them.]
We opted for making our heat exchanger out of cob, as a part of the stove itself. The disadvantage to this is that our rocket stove works most efficiently with only one particular (size) pot. But we felt like the advantages (many having to do reproducibility and the availability of materials — clay being easier to find than metal) won out in the end.
We made spiral cut-outs inside our heat exchanger (where the pot will sit) in order to keep heat in contact with the pot (and more sides of it) for longer.After letting the the rocket stove dry for a week, and then curing it with a small fire, Christie organized (at the request of several women in the village) a class on making chapatis and pancakes. All the cooking that day was done on the new rocket stove.
All our friends at Mwakiwasha seemed to really enjoy the new stove and how little wood it requires. Several women were asking us to build rocket stoves at their homes. Our answer: “No! Build it yourself.”*