Stoves using for burning wood

What size stove do I need?

As a rough guide, most stove manufacturers suggest using the following equation based on the room size you want to heat:

• depth x height x width (in metres) divided by 14 = heat load requirement in kW

This is based on a rectangular room, average insulation and an outside temperature of -1oC. You should always discuss your requirements in detail with the supplier or manufacturer, particularly for unusual shaped rooms or well insulated homes.

Log stoves

Logs are often the cheapest option in terms of heating your house with wood fuel, particularly if you have access to your own log supply. Many stoves are available with a multi-fuel option and can burn both logs and solid fuel, though it is not advisable to burn wood and coal at the same time.

Larger wood burning stoves can provide enough heat to run up to a dozen radiators, but will require frequent manual re-fuelling. These stoves are plumbed into a pumped central heating circuit which can be controlled by thermostats. If a woodburning stove is used to heat water in an accumulator tank, then the wood can be burnt more efficiently and the heat delivered to a central heating system in a much more controlled way - in this case the stove may need to be fired only once or twice each day.

Many people in the more remote parts of Scotland need heating that will operate during a power cut. Wood burning stoves and ranges can provide this, and it is possible to have domestic hot water as well, as long as the system is fed by gravity. A pumped central heating system will, of course, not work in a power cut. Indeed, a fully pumped system should not be fired during a power cut as there would be a risk of boiling the water which cannot circulate.

Pellet Stoves

Wood pellet stoves burn pellets in a similar way as conventional log burners. You can use them as small room heating stoves, with outputs of 5 -10kW [check]. With a back boiler they can provide convenient hot water and central heating. Pellets burn very efficiently and require much less manual handling than logs.  Most stoves have an integral hopper which can hold sufficient pellets for several days burning. Pellet stoves are much easier to regulate than log burning stoves, and can be left to burn all day with minimal attendance. Stoves are filled by hand using bags of pellets of 15kg upwards.

The number of suppliers of wood pellets is increasing and you should be able get them delivered in your area. The flues for pellet stoves are sometimes smaller diameter than for traditional wood and multi-fuel stoves, making them more unobtrusive and installation easier.

A pellet stove consists of a hopper to store the pellets, screw feed mechanism to transfer the pellets into the combustion chamber, electronic controls and electric fans to deliver the combustion air and to distribute the heat. The heat output is thermostatically controlled by regulating the flow of pellets into the combustion chamber. The stoves are ignited electronically and the ash falls into an ash pan at the base of the stove. Because of the high efficiency combustion the ash pan may only need to be emptied every two months.

Ranges

It is still possible to buy range cookers that can be fuelled by wood. Rayburn, Esse and Stanley sell models that can be used for cooking only; cooking and domestic hot water or cooking, hot water and central heating. More information and technical details can be found by contacting the manufacturers. With the exception of the Esse cooker, these ranges were primarily designed to burn coal and solid fuel, and therefore burn wood less efficiently; nevertheless they still work well with dry logs.

Tile or Ceramic Stoves

Ceramic stoves are wood burning stoves which are made of fired clay blocks or from carved soapstone. They are quite large structures and can extend to ceiling height. The internal flueways are very long and this leads to complete combustion of all the gases from the wood. The ceramic blocks store heat and the stoves require firing only once each day. Because of their size, ceramic stoves are best suited to new-build situations and can sometimes prove difficult to retro-fit into existing houses.

Maintenance

Stoves require regular de-ashing but a bed of embers on which to set a fire should be left.   Providing the stove has been installed and is operated within the manufacturer's guidelines, and wood burned is within the specification provided by the manufacturer, the only regular maintenance required will be thorough cleaning of the flueways, appliance flue connector pipe and the chimney.

Other considerations

If you are in a Smoke Control Area you must check whether your equipment and the fuel used is listed as exempt under the Clean Air Act. If you are located in one of the xx Air Quality Management Areas in Scotland, further restrictions may apply and you should check with your local authority.

Building Standards provide guidance on appropriate installation of wood burning systems and storage requirements.