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 combustion efficiency of well over 98%: practically all of the wood and its gases burn.
Combustion efficiency is not the same as thermal efficiency. Thermal efficiency tells how much of the energy in the wood ends up as heat in your room – the rest leaves through the chimney. Tested by SGS, an EU notified body, the Gamera 7 reaches 80.6% and the Tiny 3 75.4% thermal efficiency.
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.