Free Heat with Rocket Stoves

tiny cooking rocket stove

Well, sort of free. Mostly free.  If you like the idea of heating your home with only a 5-gallon bucket worth of wood per day, and building this stove for perhaps less than $20.00 up to around $100.00 then read on.

Rocket stoves: A rocket stove has nothing to do with rocket science.  It is basically a small upright cylinder (or mini-chimney) with a hole in the side at the bottom for putting wood in.  The ends of the wood inside the stove are burnt and the wood sticks out of the hole.  It is more efficient and makes less pollution than the traditional 3-stone fire used in many 3rd world countries.  You can make one out of a piece of metal vent, some bricks, cement, and vermiculite.  In a pinch in the wilderness you can make one out of mud and rocks (just not river rocks.  Those tend to explode when you put them in a fire).

You can make one for cooking, in which case you want to put a rack (out of pieces of rebar, for example) a little bit down into it so that the cooking pot sits down in it.  You can also put a sheet metal sleeve around your pot so the heat gets the sides of the pot as well as the bottom.  Also, the hole for the wood doesn't have to be just out the side.  You can make the stove to be shaped like the letter J, so the wood goes in vertically.

A rocket stove mass heater is for home heating, but you can also design it so it can heat food as well as your house.  With the mass heater, the exhaust from the fire, instead of going straight up the mini-chimney, takes a downward bend after that (usually they put a barrel over the chimney with a sideways vent coming out of the barrel - the top of the barrel being where you could do cooking) and goes into a horizontal thermal mass that works like a bench, and then out sideways.  By thermal mass, they mean you take vent pipe and build a bench out of clay you dig out of the ground and rubble (broken bricks and the like), and surround the vent pipe with this bench.  The heat from the stove dries the clay, but basically you don't want to ever get it wet after that. (so don't build your stove where it floods).  This thermal mass can be made into a built-in bench, or platforms for beds, or even a floor.

Here are a couple of websites about rocket stoves.  Some have videos:
www.rocketstoves.com
www.rocketstove.org
www.richsoil.com/rocket-stove-mass-heater.jsp
http://www.bioenergylists.org/stovesdoc/Scott/rocket/updated%20basic%20stove%20design.pdf Specs in a PDF format