Construction of a Rocket Stove

Rocket Stove

I experimented with the plans that Ianto Evans and Leslie Jackson prescribed in the first draft of ‘Rocket Stoves to Heat Cob Buildings: How to Build a Super Efficient Wood Fired Heater‘. I gotta tell you that it didn’t sink in the first time I read it. I understood it in principle, but it just seemed counter intuitive. The smoke goes down instead of up? Every time I’ve seen fire and smoke it goes up.

The rocket stove is a efficient wood burning device. All the heat is stored in the thermal mass; cob bench, soil bed, wall or floor. By the time the smoke leaves the building it has lost a significant amount of heat and transferred it into the building. So much that you can keep your hand on the chimney top. It’s mostly hot air and moisture leaving the flue.

The rocket stove is a down-draft heater. The oxygen hungry fire sucks air into the mouth of the stove. The fire and air move down the horizontal burn tunnel, in this case made of fire brick, and up into a insulated internal chimney. The insulated chimney was constructed with a clay tube embedded in vermiculite and clay, embedded in a metal cylinder. Then the hot air and smoke moves into a 55 gallon drum, cools ever so slightly, releasing heat into the building and sinks / is pushed into the 8″ horizontal stove pipe. The pipe is embedded in a cob bench, releasing the heat into the thermal mass of the bench there by storing it like a battery. From the bench the pipe leaves out of the building.


The second edition, Rocket Mass Heaters-Superefficient Woodstoves You Can Build (and snuggle up to) is available here:


3 Responses

  • gud day,i’m very much interested to have a rocket stove, i wish to see the photo copy inside

  • John says:

    Bill, why can’t you see it as viable? The system can be scaled with larger diameter pipes and burn tunnel using larger wood if needed. I looked into masonry heaters and there is a great book written about them. Tracing their building is Europe. The basic principle of burning a small hot fast burning fire then feeding the flue through a thermal mass has been used in many countries with intensely cold winters. This design just brings it back to the owners ability to create a safe warm way to heat their own home.


  • I do think Rocket stoves are very cool to play around with but in the north I cant see it viable for heating even with a thermal mass available….

    Survivalbill dot ca