Zero's Ultra-Efficient Wood Burning Rocket Stove Heater Plans
Rocket Stove Mass Heater is a wood-fired heater with an internal riser or flue, covered by a barrel with a long exhaust pipe that runs through a cob (a mixture of clay and straw) thermal mass which functions as a heat battery. This gives off stored heat in between burns in the mornings and evenings when the family is asleep and you don’t want to burn wood to waste.
Design variations include the ‘Pocket Rocket' and Mini-Rocket Stoves that are mainly designed for cooking.
Rocket Stoves are built with an innovative technology that makes them burn clean with a vertical heat riser or insulated internal chimney, which results in extraordinary heat capture and low waste from a small amount of wood. The goal of the Rocket Stove includes:
- Help meet the human need for warmth, food, comfort, and safety.
- Conserve fuel by avoiding over-harvesting of firewood which causes droughts, famine, and climate change.
- Enhance clean air by reducing the amount of smoke emitted by stoves.
- Turn wastes into resources such as finding new uses of waste and scrap.
- Encourage resourceful thinking and hands-on problem-solving technique.
- Offer affordable, clean alternatives to conventional technologies.
Rocket stoves primarily use the chimney or “hot stack” to draw pyrolytic gases through a hot zone for complete combustion.
You will find different designs of rocket stoves for different purposes. Some are cook stoves while others are curated to provide heating in homes, metalworking, or water heating.
The key benefits of Rocket Stoves are:
- Rocket Stove has a consumption rate of 1/10 and provides effective heating for your home.
- Produces no smoke or carbon monoxide byproducts, instead, it emits carbon dioxide and steam.
- Very easy to clean up due to its small ash buildup.
Key Features of Rocket Stoves
- They have a vertical wood inlet to a small firebox,
- Have a horizontal burn chamber,
- The insulated internal flue or riser,
- A drum or barrel over the riser for gases to cool and give off heat,
- An exhaust at the bottom that often extends through a cob bench to slowly store and release heat.
How Rocket Stoves Works
Any wood stove requires creating a draft to pull air into the firebox for the wood to combust. In average, a wood stove sends 80% or more of the heat created by the burning wood up the chimney flue and out. This means that it will give off only leftover radiant and convection heat transferred to the body of the stove and subsequently into the room.
A Rocket Stove, by contrast, is capable of scavenging almost all of the otherwise wasted exhaust heat without buildup of creosote or other deposits.
Here is how that happens.
When a fire is ignited in the firebox of this stove, it just takes a puff of breath or two down over the firebox to get the hot gases to start traveling through the short horizontal burn tube and up the internal riser. Once the heat starts ascending up the riser, the process becomes self-sustaining.
The Rocket Stove functions properly when the heat reaches the inside of the internal riser.
From the moment the gases exit the top of the riser and down the sides of the barrel, they begin to cool. The draft created by the riser behind the cooling gases should be so strong that it pulls in fresh air behind it and also pushes exhaust gases out ahead of it without the need for any additional draft created by a typical chimney flue. This is the reason why the internal riser should be insulated so that it creates a super strong draft in a very small space and provide the environment for the secondary burn of any unburned gases.
How to Build Your Own Rocket Stove
The first thing you need to assemble is the required tools, the skills you learn in the manual. The tools include:
- Mig welder (flux core is fine or gas if you have the extra cash).
- Sheet metal bending brake.
- Tin snips.
- Angle grinder with grinding wheel and cutting disks.
- Drywall square.
- 12” bubble level.
- Sharp indelible marker.
The next thing you need to consider before starting to build the stove is the size. The size depends on the amount of space you need to heat with the stove.
- Find your own perfect barrel, drum or tank
If you can access a compressor tank, it will be the perfect choice because it is light with thick sidewalls. Alternatively, you can use the discarded electric hot water tanks, slim propane cylinders, artesian well water storage tanks, stacked and welded 20lb propane tanks and more.
- Determine the internal sizes of your riser, burn tunnel and feed tube
This is commonly known as the J-Tube, and you need to be careful with the internal size of your riser, burn tunnel and feed tube to avoid:
- Emissions of poisonous gases from the burning zinc galvanize.
- Short lifespan caused by rooting under the extreme heat.
- Melting of the fiberglass wool.
With the right tools and material, the manual will direct you on how to build yourself a Rocket Stove and provide heat to your homestead.