Wood burning stoves

A wood-burning stove (or wood burner or log burner) is a heating appliance capable of burning wood fuel and wood-derived biomass fuel, such as wood pellets. Generally the appliance consists of a solid metal (usually cast iron or steel) closed fire chamber, a fire brick base and an adjustable air control. The first wood burning stove was patented in Strasbourg in 1557, two centuries before the Industrial Revolution would make iron an inexpensive and common material, so such stoves were high end consumer items and only gradually spread in use.

The stove is connected by ventilating stove pipes to a suitable chimney or flue, which will fill with hot combustion gases once the fuel is ignited. The chimney or flue gases must be hotter than the outside temperature to ensure combustion gases are drawn out of the fire chamber and up the chimney. Many wood-burning stoves are engineered such that they can be converted to multi-fuel stoves with the addition of a grate.

Keeping the air flowing correctly through a wood-burning stove is essential for safe and efficient operation of the stove. Fresh air needs to enter the wood compartment to provide oxygen for the fire; as the fire burns, the smoke must be allowed to rise through the stove pipes, and exit through the chimney. To regulate air flow, there are damper devices built into the stove, flue, and stove pipes.

By opening or closing the dampers, air flow can be increased or decreased, which can fan the fire in the wood compartment, or "dampen" it by restricting airflow and reducing the flames. The dampers can usually be accessed by turning a knob or a handle attached to the damper, found outside the stove or stovepipe. One of the uses of the dampers is to increase airflow into the wood compartment to raise flames and thus the temperature of the stove, to temporarily create a high heat for cooking.

High heating efficiencies on closed appliances can only be attained by controlling the supply of air to the fire chamber (operating the air control correctly). It is not recommended to leave the air control fully open, except when helping the chimney/flue heat up initially. A fully open air control will lead to more heat being sent straight up the chimney rather than into the room (which reduces efficiency). The biggest problem with leaving the air control fully open is “overfiring”. Overfiring is caused when too much heat is generated within the fire chamber, which will lead to warping, buckling and general damage to the stove and its internal components. Individual stoves will have their own quirks, so it is necessary to learn each new stove's settings.

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Wikipedia