The amazing simplicity and efficiency of rocket stoves as space heaters, stoves and mass water heaters. What is a rocket stove, how does it work and how to make your very own rocket stove, covered here!


After researching and pricing solar water heating systems, I went on to look at back up water heating systems for the solar geyser and came across the Rocket Stove Mass Water Heater. I love things that are multi-functional and can offer redundancy back ups to systems when living off grid. So of course the rocket stove, which can be cooked on, used to heat a whole home and heat water for showering, grabbed my interest immediately!

Off Grid In South Africa Our Journey banner

Follow our off grid journey as we go from looking for land to building our off grid home.

We are on a journey to living off grid and self sustainably in South Africa.

Along the way, we’re doing a lot of research into various topics involved in this lifestyle.

Off Grid Living In South Africa banner

Browse articles with information and tips on off grid living in South Africa

What Is A Rocket Stove?

In essence, a rocket stove is a “J” or elbow shaped contraption with 3 defining features.

1. At the bottom end of the J is a small opening called the feed, where you add your fire’s fuel.

2. Underneath that is a gap to allow air to flow in.

3. Then you have a long chimney or heat riser, its length having a ratio of 5:1 or 6:1 in relation to the feed.

There’s other types you can look up as well, like the “batch box” style.

Rocket stove diagram
Image from Instructables

What’s So Cool About A Rocket Stove?

  • It can reduce smoke and harmful emissions (less air pollution).
  • They use less fuel (some say up to 80% less than a traditional wood fire) to create more heat.
  • You can use any dry plant matter, not just wood – it’ll cook a meal with some dry leaves and twigs.
  • More efficient cooking.
  • Inexpensive to use and inexpensive to make.
  • Can heat a home, heat water and be cooked on!
Rocket stove space heater built in
Rocket stove heater built into cob home

How Do They Work?

Rocket stoves, unlike rockets, are actually very low tech. They get their name from the sound they make when they burn.

What makes them so efficient is the airflow – the air rapidly gets sucked up the heat riser (pipe) which causes the fuel to burn super hot and almost complete combustion of the fuel happens.

As a result, very little smoke is released while a lot of heat is created. Below is a great little video demonstrating how a rocket stove is used to heat a space efficiently.

Great explanation and demonstration of a batch style rocket mass heater by ABC Acres

Make Your Own DIY Basic Rocket Stove

You can make a basic rocket stove out of various materials, depending on what you have available, your preferences and what you want to use it for.

For example, if you’d just like to use it to cook a one pot meal, a simple 16 brick stove will do the trick. I’ve seen them made from left over cement, welded together metal, clay and cinder blocks. Aim for the 5 or 6 to 1 ratio from feeder to heat riser and you’re ready to go!

Rocket Stove Mass Water Heater

After researching and pricing solar water heating systems, I went on to look at back up water heating systems for the solar geyser and came across the Rocket Stove Mass Water Heater.

If you’ve got time, these two videos below demonstrate the basics. There is a ton of information online and you can really adapt your build to suit your unique requirements.

This shows a rocket stove mass water heater at its most basic
This one’s by Geoff Lawton (love his videos!) and gets more detailed – really worth a watch.

Our Plans

Well, I’m in love with the whole concept!

We have bought a small metal rocket stove (found it on Gumtree for R550) to try out while we camp on our land.

Once we’re familiar with it, I’d like to experiment with building up around the stove with insulation to create a larger cooking surface and heat retention area.

I figured metal would be a good base / core to build around.