Types of wood fuel
Wood is a versatile fuel that can be utilised for heating in the home or on a larger scale in offices, workshops and community facilities. There are 4 main types of wood fuel - Click on the images below for further details
The type of fuel you use will depend upon the size and complexity of space you wish to heat, the storage space available and the level of automation and control you wish to have.
What’s right for you?
First, you need to decide what system will do the job you need it to do. Know whether you are looking at a multi space heating system, (primary heating) in which case you need to be looking at log or pellet boilers, or whether you are looking to heat one room, for example just the sitting room, (secondary heating) in which case you will need to be looking at log or pellet burning stoves. Unless you live in a very large house, wood chip systems are not appropriate for the domestic situation.
Advice and guidance for home owners is available in ‘A Householders Guide to Wood Fuel’. Click the image below to read.
For developers, designers and planners of larger projects
Wood fuel heating technology can work at all scales. Be it for a single room, a whole building or multiple buildings, there is a wood fuel solution.
For larger buildings, community and district heating, automated chip or pellet boilers fulfill the same role and can run at typical efficiencies of 85%. When planning for wood heating systems on a larger scale it is important to consider the time, staff and resources that those owning the system will have to dedicate to loading, maintaining and monitoring the system. Also, large primary boiler systems need large and accessible fuel storage facilities, consideration must be given to ease of fuel delivery and appropriate dry and safe storage. The level of involvement and space available will dictate the type of system and fuel suitable for your project.
Advice and guidance for larger projects is available in ‘A professional’s guide to wood fuel heating’. Click the image below to read.
Here are some answers to a few common questions:
Q – Where will I get my wood fuel from?
Research the wood fuel products available in your area. Ideally you want a ready supply of quality logs / pellets / chips / briquettes to be sourced locally, as that will keep delivery costs as low as possible. Don't discount pellets, briquettes or kiln dried logs if they are not made nearby – the transportation networks are improving all the time and a dry storage space the size of a garden shed might be enough to store a year’s supply.
Q –Can I use any type of wood to burn in a boiler or stove?
No! You need to consider the quality of the products available and the specifications of your appliance manufacturer. A common misconception is that you can use un-seasoned logs (generally above 25% moisture content) to burn in your boiler or stove. This is absolutely not recommended as it will be inefficient and may damage your actual appliance. You should never use treated or painted timber.
Q- What must I have in my home to make wood fuel a good option for me?
You need to consider how the whole system will fit physically within your property. Although work can be carried out to install any type of burner, you need to be aware that a log stove will need a proper chimney. Therefore, for those in more modern homes or in, say, a flat, a pellet burner might be the cheaper and simpler option to install. A log stove could be serviced by as little as a few square feet in a porch to store logs that are delivered weekly, whereas a boiler system would need space in a utility room or outbuilding, as well as greater storage space. You also need to consider transportation of the fuel to the fire – you don’t want to be barrowing wood for an hour a day because your store is too far from the boiler! Ash also needs to be disposed of: if you have a garden, you can use it as a soil additive, but if you don’t, you will need an outdoor space to allow it to cool before binning it. A large wood boiler will generate a lot of ash, whereas a domestic pellet stove creates as little as a handful a day.
Q- Would switching to wood fuel affect my lifestyle in any way?
Think about the aesthetics! Do you like sitting around a real log fire of an evening? If so, a boiler in the garage might not do the job, and a pellet stove certainly does not compare with the flame and look of a log fire. Wood fuel does have an impact on your lifestyle. A log stove will require regular manual refueling, whereas an auto-feed pellet boiler will feed automatically from the hopper. An indoor pellet burning stove may only require a few shovels-full of pellets per day which might be a useful consideration for those who couldn't manage – or don’t want to manage – carrying logs from store to fireplace. If you are away from home all day, a stove fire may mean you return to a cold house, so maybe a wood fueled boiler would be better. Pellet stove burners have temperature controls, so they could be left on low during the day, and then turned up during the evening when people are sitting in front of them.
Q- How efficient are wood burning stoves and boilers?
Once you have decided upon your system, research the makes and models. Open fires may look nice, but they only operate at around 15-20% efficiency, whereas modern wood-burning stoves will operate at a level of 70-80% efficiency. Wood fuel boilers can work even more efficiently and reach highs of 85-90%. These figures are offered as an industry guide and you should take into consideration variations between different manufacturers and models. Even if you already have an appliance – consider up-grading it: newer models have a far higher rate of efficiency, and pay-back time for the investment could be small.
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