Most wood stoves simply resemble a box, and we take heat from that box to heat a room.
If you look at the burning page, you will learn we want to keep the fire as hot as possible, to burn all the smoke. So burning in a box, directly taking the heat out, will cool the fire and keep it from burning at top efficiency. This also means a lot of energy will escape the chimney in the form of annoying smoke and soot.
A rocket stove uses temperature, turbulence and time, to keep those gasses in the stove hot enough to burn fully. Only after this is done, we collect as much heat as possible.
So we get a lot more energy out of the wood, with burning off that smoke, we get to a burn efficiency of well over 98%.
This results in much more heat from your wood, no neighbor annoying smoke, and you will have to clean your chimney much less.
Want to get technical about it?
All Gamera models stoves are based on the principles of the so-called rocket heaters that features “L” – shaped burning chamber.
The fuel is loaded vertically inside the primary combustion chamber where the same processes take place as in regular stove but upside down. The air
intake is in the center of the fire pit and the draft leads the air
down, around the fuel and inject the flames in the horizontal tunnel on
the lower back side of the primary combustion chamber. The low horizontal tunnel leads the products from the primary combustion (heat, wood gas and smoke) to the vertical part of the burning chamber (heat riser) which acts as an inner chimney. It is made of hi-heat resistant material that is additionally insulated. The secondary burn takes place iside the heat riser which heats up to 1000C. All smoke and gases released from the fuel during the primary combustion self-combust here, generating twice more heat and decomposing to 99% CO2 and water steam.
Schema
How it looks inside, so, where the magic happens.
After leaving the heat riser the exhaust gases (99% H2O and CO2) hit the top metal plate of the stove’s body. Afterword flows through the gap between the burning chamber body and the metal corpus of the stove. The metal body acts as a heat exchanger. No burning is taking place here. Because the hot gasses run all around the body they cool down. This leads to excellent heat release on one hand and creates own draft on the other. The exhaust gases leave the stove from outlet witch is at the bottom of the stove with mid temperature around 140C.
The animation better depicts what happens in the combustion chamber. Hitting in the heated walls of the heat riser smoke and wood gas burns and gas remains 99% water vapor and CO2.
Because of its high efficiency the heater consumes 2 to 3 times less fuel and does not produce any soot or creosote,
this means that you will have to clean your chimney much less, if at all.
Since Gamera stoves uses relatively thin wood it is not necessary to buy regular firewood. Much cheaper alternatives can be found as offcuts from wood processing industry, branches that are left away or offcut from construction timber. In such cases the cost for heating can be reduced ten times!
Eco-briquettes are excellent fuel also. They are very convenient with more caloric value than wood given the same volume, have longer refuel period and are cheaper than pellets. Pellet are not suitable fuel!
The core is made from expanded vermiculate 25mm thick. Its maximum
working temperature is up to 1100C. It can withstand 1200C for short
periods.
The body is made of black steel 1.5mm to 4mm thick. It is designed for optimal heat exchange, durability and weight.
Gamera stoves are designed to last at least ten seasons under normal operation and storage.
Main disadvantage of the rocket heater is the indispensability of frequent watch over.
In its efficiency class it competes only with pellet heaters but it is not dependent on electricity and is not confined to one type of fuel.