Brief description

A rocket stove is an efficient and hot burning stove using small-diameter wood fuel. It achieves high combustion efficiency by ensuring a good air draft and a well-insulated combustion chamber.

Use / Function

• Primary use: Efficient cooking with minimal fuel.
• Secondary uses: Space heating (Rocket Mass Heaters), water heating.
• Scale: Small portable units to large built-in home heaters.

Operating principle

The L-shaped combustion chamber:

1. Air Intake: Fuel is fed into the bottom of an L-shaped tube. Air enters below the fuel.
2. Combustion: Wood burns at the corner of the L.
3. Chimney Effect: The vertical part of the L acts as an internal chimney, creating a strong draft that pulls in air and keeps the fire hot.
4. Insulation: The chamber is heavily insulated so that the fire burns as hot as possible, ensuring near-complete combustion of gases and smoke.

How to create it

1. The Chamber

• Create an L-shaped tube using Metal pipes or Bricks.
• The horizontal part is the fuel feed; the vertical part is the combustion chimney.

2. Insulation

• Place the L-chamber inside a larger container (like a 5-gallon bucket or a brick structure).
• Fill the gap between the chamber and the outer container with an insulating material like Perlite, Vermiculite, or wood ash.

3. Pot Support

• Place a pot support at the top of the vertical chimney, ensuring there is enough gap for the hot gases to escape around the bottom of the pot.

Materials needed

• Internal Chamber: Steel pipe, fire Bricks, or Clay.
• Insulation: Wood ash, Perlite, or dry Stone.
• Outer Shell: Metal cans, drums, or Masonry.

Variants and improvements

• Rocket Mass Heater: The exhaust is piped through a large thermal mass (like a cob bench) to store and slowly release heat.
• Institutional Rocket Stove: Large-scale versions for schools or hospitals.

Limits and risks

• Fuel Preparation: Requires fuel to be broken down into small sticks.
• Carbon Monoxide: Like any stove, it must be used in a well-ventilated area or vented outdoors.
• Heat: The vertical chimney and the area around it get extremely hot.