Rocket stoves come in four layouts: the L-tube, a horizontal feed turning into a vertical riser, which is the simplest and most forgiving; the J-tube, with an upright or angled magazine that feeds itself by gravity; the rocket mass heater, which sends the exhaust through a thermal mass to heat a room; and the multi-pot stove for groups. For survival use, build the L-tube first.
Part of Rocket Stove Design
All rocket stoves share an insulated burn tunnel and a riser. The variations change how fuel is fed and where the heat goes.
The Layouts Differ In Feeding And In Where The Heat Goes
| Layout | Fuel feed | Heat goes to | Page |
|---|---|---|---|
| L-tube | Horizontal; push sticks in | One pot | J-Tube vs L-Tube |
| J-tube | Upright or angled magazine; gravity | One pot | J-Tube vs L-Tube |
| Mass heater | Either, then a long duct | A bench or wall that stores heat | Rocket Mass Heater |
| Multi-pot | Long horizontal chamber | Several pots in a row | Multi-Pot |
Choosing
- Cooking for a household: L-tube.
- Less attendance, more building skill: J-tube.
- Heating a room: mass heater, but only with a complete exhaust to the outside; this is a Phase 2 project, see Heat Storage Systems.
- Feeding 10 or more people: multi-pot.
Common Mistakes
- Starting with the mass heater. It has the most places for exhaust to leak into a room.
- Changing the riser to suit the pot. Adjust the pot support instead.
- Assuming a bigger stove is a better one. Fuel and draft must balance.
Safety
Every variation burns fuel and makes exhaust
More ducts, more joints and more thermal mass mean more places for smoke and carbon monoxide to escape, and carbon monoxide has no smell. Use any variation outdoors, or with a sealed exhaust to the outside. See Carbon Monoxide Risks.
What’s Next
- Learn next: J-Tube vs L-Tube — choosing a feed
- Combine with: Fuel & Operation — running whichever you build