Buying Wood Fuel on the Isle of Wight

It is better to buy wood by volume than by weight because between 35% and 60% of the weight of freshly felled wood comes from water. Poplar is one of the wettest woods when freshly fuelled and ash (at 35%) one of driest. Trying to burn wet wood will produce steam, less heat (as so much of it is being used to dry the wood) and problems with the chimney and pollution.

Seasoning reduces the moisture content of the wood. Wood felled during one winter should be seasoned until the next and preferably a second winter before it is burned. Trees felled during the Spring/Summer will have a very high moisture content compared to those felled in late Autumn/Winter, therefore whilst a log first cut in January may be ready to burn within say, a year, it is necessary for a log cut in May to be seasoned for at least two years.

Whilst seasoning it should preferably be stored under cover in an airy place such as an open sided lean-to. Wood should be burned when the moisture content is below 25% – ‘air-dry’. Your can tell if a log is dry because the bark will come away easily in the hand and the log will have splits across the grain. Ideally, logs purchased should be no more than 10cm thick. Any that are will need to be split again to ensure that they burn properly.

What wood to burn?
In terms of what type of wood to burn it is worth bearing in mind the heavier and therefore denser the wood, the higher its calorific value and therefore the longer it will burn. Hardwoods tend to be denser than softwoods such as pine and spruce and some of the densest are oak and beech. However, some of the very dense hardwoods like oak and elm can be very difficult to burn, so it is usually best to burn them with another type of wood as well. Softwoods tend to be easy to light and to burn quickly (making them very good kindling). Some species like spruce and horse chestnut spit badly making them a hazard in an open fire.
Some of the best woods to burn are ash, beech, hornbeam, hawthorn, crab apple and wild cherry.

Where to burn wood? Open fires or stoves?
Wood is a very versatile fuel and can be burned in many different forms and in a number of different appliances. It can be burned to heat one or more rooms, the whole house, to produce hot water and to cook on or a combination of all or some of these.
To produce heat for one or more rooms logs can be burned on an open fire. These look nice, but tend to have low efficiencies – about 80-85% of the heat goes up the chimney. A more efficient alternative is a wood burning stove, which have efficiencies in excess of 70%. With the right wood burning stoves wood can be burned in a smokeless zone. Some stoves can also be fitted with back boilers to heat one or more radiators or domestic hot water.
Logs can also be burned in a ceramic stove. These have extensive internal flues and can retain heat for up to 24 hours after the last firing. They can be around 90% efficient and some can be used in smokeless zones.
Another option is a range. Ranges can be used for cooking, hot water and central heating.
There are also many domestic scale log and wood-chip burning central heating boilers available. Using wood to heat commercial and public buildings is common in countries such as Austria and Sweden. Pellet stoves and boilers, using pellets made from waste wood are another possibility. They can be purchased new or the necessary adaptation equipment retrofitted to an existing coal or oil boiler.

How to burn wood?
Like other fuels, wood needs plenty of air to burn well. It is best to allow a fresh change of logs to burn freely until they almost turn to charcoal and only then to ‘damp’ down the fire by reducing the air supply. Filling a stove with logs and damping it down straight away, stops the ‘volatiles’ from burning and generates a lot of smoke and tar that is bad for health and the environment.

Emissions
The main emissions from a wood fired plant burning clean wood from forests or coppice will consist largely of water vapour and carbon dioxide (plus nitrogen and oxygen from the combustion of air). The emissions will also contain traces of carbon monoxide, particulates and volatile organic compounds. However, these emissions are not exclusively produced by burning wood. They are also produced when fossil fuels like gas and oil are burned to produce energy. However, this is not a reason to be complacent. Instead it highlights the needs to consider seriously the appliance that the wood is burned in and the quality of the wood fuel that is used.
On a more positive note, wood smoke contains almost no sulphur dioxide and very little in the way of nitrous oxides. This means acid rain is not produced as a result of burning wood. In addition, it should be noted that the carbon dioxide released when wood is burned is the same as that absorbed by the tree when it was growing.
Wood can release pollutants into the atmosphere when poor burning techniques are used. The hazards include smoke and carbon monoxide.

Logs
Logs are the most common type of wood fuel used on the Isle of Wight. They can be bought in bags, or by weight or volume. You will pay more for seasoned wood and hard wood.

An old and anonymous woodland poem advises:
Beechwood fires are bright and clear, If the logs are kept a year.
Chestnut’s only good, they say, if for long ‘tis laid away.
But Ash new or Ash old is fit for a queen with crown of gold.
Birch and fir logs burn too fast, Blaze up bright and do not last.
It is by the Irish said, Hawthorn bakes the sweetest bread.
Elm wood burns like churchyard mould, E ’ en the very flames are cold.
But Ash green or Ash brown is fit for a queen with golden crown.
Poplar gives a bitter smoke, fills your eyes and makes you choke.
Apple wood will scent your room, with an incense like perfume.
Oaken logs, if dry and old, keep away the winter’s cold.
But Ash wet or Ash dry, a king shall warm his slippers by.

Woodchip
Woodchip is more expensive to buy than logs, but can offer a more practical, less bulky storage and automated feed solution for boilers.

Turning woody material into logs or chips is a straightforward operation. Making sure that the logs or chips meet the needs of specific customers is more complex.
Whilst larger boilers over 400kW output may be able to burn wet woodchips, smaller boilers need dry chips of a moisture content of 30% or less.
Standards have been developed for solid fuels including woodchips (CEN 355). The main criteria are:
Raw material
Size of chip
Moisture content

It is important to determine that chips purchased are suitable for boiler specifications. There are only a few Island producers currently supplying local woodchip.

Kindling
Ideally, any kindling purchased should be cut to an ideal, uniform size. If packed into easy-to-handle red net carriers or in weatherproof polythene bags with micro-perforations, the product is able to breathe.

Purchasers should ensure kindling is tinder dry, clean and free from wood fragment mess.

To find Island suppliers able to offer this product please use the Directory