Wood Burning Stoves are Environmentally Friendly
Wood burning stoves are one of the most cost-effective forms of renewable power that you can incorporate into your home. By 'renewable' we mean that wood used for fuel can easily be replaced by simply growing more - in fact wood experts tell us that if everyone switched to wood burning stoves the UK could quickly become self-sufficient in wood fuel once our woods were properly managed and coppiced. Providing the wood fuel is harvested from a sustainable wood source then there is no net increase in CO2 emissions (the most significant greenhouse gas). At the moment in most woodlands wood is left to rot and is regarded as a waste material.
The Woodland Trust, the UK's leading woodland conservation charity, encourages the planting of trees for wood fuel and state: Using wood fuel to produce heat can be an excellent low carbon alternative to coal, oil and gas, but it depends on having a local, sustainable supply. The carbon released when wood is burned is effectively recaptured by growing replacement trees. This is much better than using fossil fuels, which add carbon dioxide to the atmosphere: using wood fuel avoids those extra emissions (http://www.woodlandtrust.org.uk/). A well managed wood provides a diverse habitat for wild life and even a pile of wood left to season creates a home for insects which can then attract a variety of different birds.
Wood burning stoves are also very efficient. A high quality stove operating with an efficiency of up to 85% also looses very little heat through the flue and produces very little smoke pollution. Compare this to an inefficient open fire operating at around at 10%. The more inefficient then the more polluting it is.
Although stoves are not quite as efficient at producing heat as a modern central heating boiler, they effectively have a zero carbon footprint, since any carbon dioxide produced by burning wood fuel is simply the same carbon dioxide which was absorbed by the tree when it was growing and you can't say that about a gas or oil boiler. A good wood burning stove is also between 20% to 30% more efficient than a typical gas fire or room heater which only operates at around the 60% efficiency mark.
Studies in Australia and the USA have shown that an open fire draws huge amounts of warm air out of the room to 'feed' itself and thus produces a negative efficiency. The warm air the open fire has used is replaced by colder air from further inside the house, or even from outside, making the house generally feel colder despite the appearances of a roaring open fire. It's no wonder that in today's new homes it is almost impossible to specify an open fire without having to compensate for its inefficiency and poor environmental credentials with additional, often expensive, insulation.
In contrast, recent changes in Building Regulations now highlight the specific benefits of installing a wood burning stove, both in meeting the government's 20% carbon emissions reduction targets and also in homeowner appeal. The new rules set out more stringent requirements for the energy efficiency levels achieved by houses. From now on secondary heating appliances, including wood burners, have to be specified as an integral part of completing the Standard Assessment Procedure (SAP) calculation which is used to calculate the overall energy efficiency and carbon output of a house. The performance of these appliances, associated chimneys and flues and building elements such as thermal insulation and glazing are all now considered together to arrive at a carbon emissions calculation. Any elements which are likely to increase the use of energy must be balanced by greater thermal efficiency elsewhere in the house. For example, an open fire, then higher levels of insulation with increased costs may be required to offset this.
A key element within the SAP calculation methodology is the adoption of electric heating as the 'default' secondary heating source. However, as we all know electricity is a carbon intensive energy source. So this means that secondary heating appliances with carbon efficiencies better than electric fires, such as wood burning stoves, will offer a considerable carbon credit which can be 'traded off' in other areas of the house design. By making the appropriate choice in this key area important savings in carbon emissions can be achieved, giving a markedly better SAP result than the default electric heating used in the calculation. Apart from that, wood burning stoves are simply a great looking visual asset in any home which, as any wood burning stove owner will tell you, will save you money on your heating costs and will be a pleasure to live with.
A detailed explanation of the SAP calculation method and comparisons on the performance of different types of appliances in conjunction with natural draught flues can be obtained by downloading this pdf from the Chimney development association.
People wrongly associate wood burning stoves with producing a lot of smoke. At The Stove Yard showrooms in Newtownards and Holmes Chapel we operate 7 live wood burning stoves and even when all are burning at there is very little evidence of smoke (except minimal smoke from the flue terminal on initial firing and which only lasts about 15 minutes) and there isn't even the smell of wood smoke inside or outside either of our showrooms. Smoke from wood burning stoves is caused by burning wet or unseasoned fuel, non-approved fuels such as household rubbish, an inefficient, cold or damp flue (see 'Problems with Flues section) or simply starving the stove of combustion air to slow down the burn rate for overnight burning (not recommended by good manufacturers, Hetas or the Solid Fuel Association). A DEFRA approved or Smoke Exempt Appliance, which allows you to burn wood in a UK designated Smoke Control Area, has met stringent emissions criteria and providing seasoned wood (less than 20% moisture content) is used is virtually impossible to burn in a way which would create nuisance smoke. Significant improvements are being made to stoves every heating season, such as the addition of pre-heated secondary and tertiary air, which are all combining to create more efficient and better performing stoves which are further reducing smoke and pollutant levels.