A cleverly designed convection-fueled air duct directs preheated air at 300°C back into the top of the combustion chamber that ignites the smoke (smoke is just unburned fuel).
The stove also utilizes an insulating heat shield, made of a highly reflective grade of stainless steel, as an insulator around the chimney or fire chamber. This not only serves to contain the heat but it also creates an envelope in which tertiary air is pre heated to around 300 degrees centigrade.