What is the best fuel for my wood burning stove?
Posted by Helena Ripley on 18 August 2015 at 1:40 pm
A stove is a good way to heat a single room when it isn’t cold enough to put the central heating on, or when you want to create a warm cosy atmosphere. But what is the best fuel to use?
Before discussing the types of fuel that are available, it is worth noting that some urban areas are smoke controlled. In these areas you would either need a DEFRA exempt stove or to use a smokeless fuel, such as anthracite.
When using logs as fuel the moisture content must be less than 25%; if there is more water in the wood than this it will not burn efficiently. Burning wet wood results in a visible smoke, which is polluting, and a build-up of tar which can lead to a chimney fire. There are several options for getting dry wood fuel: You can buy unseasoned logs then leave them for a year to dry out, but this requires a large space. Another possibility is to buy kiln dried logs: this is a more expensive type of wood but it will save you space as you won’t need to store as much fuel. If you are lucky enough to have your own supply of wood you do need to make sure that the moisture content is low enough. You can get a rough idea just by feeling and looking at it, as dry wood is lighter and often has radial splits. But in order to be certain, you can also easily buy a moisture gauge online- just type “firewood moisture meters” into your search engine.
The best species of wood to burn are ash, beech, hawthorn, rowan, thorn and yew. These all burn slowly and have a good heat output. Two species to definitely avoid are laburnum and poplar, as they both burn badly with a lot of smoke.
To cut down on the cost of fuel for their stove some people collect waste wood from skips or use other waste wood, such as old pallets. However, it is difficult to tell if this wood has been treated with chemicals, so it’s not a good idea to burn it. If you are going to, then obviously you want to avoid painted or varnished wood. Plywood and MDF should also never be burned as they can release toxic urea-formaldehyde vapour. In short, waste wood should only be burned if you know the source and are sure that it is untreated. If you’re interested in this option, check with local tree surgeons or carpenters.
Pellets are not particularly common as a fuel for wood burning stoves in the UK. They are usually made of recycled or waste wood, particularly sawdust. Wood pellets can only be burned in a stove specially designed for their use. Compressed wood briquettes, which are similar to pellets, can be bought online. These are more efficient than logs as they are very energy-rich and very dry.
While coal might be a very energy dense fuel, giving out a lot of heat and burning slowly, it is also the most polluting. Various brands of coal are available. It is best to steer clear of coal altogether if you are concerned about your carbon footprint. If you are in a smoke restricted area and don’t have a DEFRA exempted stove you will need to use smokeless fuel. The most well-known of these is anthracite which is a form of coal.
It is most cost effective to buy fuel in large amounts, but this does mean that you will need the space to store it. All fuels will vary in price depending on your supplier. Wood can cost nothing (if you have your own supply), between £50 and £100 for about a ton, if you buy it but season it yourself, to around £150 for 300kg of kiln dried wood. (Figures based on prices from Logs2u and The Luxury Wood Company). Pellets are more expensive, costing around £120 for 250kg, but the prices come down if you buy a larger quantity: a ton will set you back only £260. Solid mineral fuels such as coal start around £110 for 250kg or £300 for a ton.
There are many types of fuel available for use in a stove. If you’re looking to save money and have a substantial and dry storage area, then bulk buying is your best option. To reduce your carbon footprint, locally sourced sustainable wood is best. Some people find that a mix of fuels is the best option for heat and duration: if you do want to go down this route, you’ll need a multi-fuel stove. Finally, if you live in a smoke control area and don’t have a DEFRA exempt stove you will need to burn approved fuels.
If you are interested in seeing wood burning stoves in place you can visit homes with wood stoves during SuperHome Open Days in September.
Photo credit: SuperHomes
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