Wood-burning stove

A heating appliance capable of burning solid wood/Biomass fuel. Generally the appliance consists of a solid metal (usually cast iron or steel) closed fire chamber, a grate and an adjustable air control.The appliance will be connected to a suitable chimney or flue, which will become hot once the fuel is ignited. It is critical that the chimney or flue is hotter then the outside temperature as this will result in combustion particles to be drawn up th chimney out of the fire chamber.

Closed appliances offer far greater efficiency as the user can control the combustion inside the fire chamber through the air controls (this ensures that the wood burns at a controlled rate). Heat is transferred to the room by convection as the stove body becomes hot. Open fires suffer from lower efficiency as they have access to far greater oxygen supply, which causes them to roar away meaning that more heat is sent up the chimney rather than into the room.

Additional Information

As fuel costs soar and people are becoming increasingly concerned about the environmental impact of burning fossil fuels, there is a real need to find sustainable and environmentally friendly fuel sources.

Clearly there are different types of wood, but basically they will usually fall into either the hardwood or softwood types. Hardwoods derived from broadleaf trees offer the greatest outputs and will burn at a slower rate for sustained output, however these trees are slow growing. Softwoods are derived from evergreen trees such as conifers, they are fast growing but burn at a far greater rate.

One of the most critical factors in wood burning is the moisture content of the wood, this is where wood seasoning comes into play. Freshly cut wood will contain a moisture content of around 65-90% this wood will produce very low outputs and will also generate large amounts of soot and tar (this can potentially lead to chimney fires as these particles will coat your chimney and will fuel a chimney fire). For best results wood should have a moisture content of less than 40%, the process of removing the excess moisture is called seasoning. Seasoning is basically air drying the wood and can take up to two years, wood is stored in a well ventilated (but covered) structure outdoors.

High heating efficiencies on closed appliances can only be attained by controlling the supply of air to the fire chamber (operating the air controls correctly) therefore leaving the air control fully open is not recommended beyond the point of getting the chimney/flue hot initially.