Stocking up with firewood for the winter

By Eva Neumann Sep 29, 2011, 3:06 GMT

Berlin - Before winter sets in people who heat their homes with stoves or open fires should consider what kind of firewood to burn.

It's not as simple as it sounds. There are a number of critical things to understand before ordering or heading out to pick up firewood.

Softwoods, for example, have a higher heat value, while hardwoods release a more pleasant scent. The consumer must also be able to calculate how much wood he needs to ensure that the stove or fireplace can be lit at any time.

How much wood to have available depends, of course, on usage. People who have fireplaces for ambiance should have 3 to 4 loose cubic metres of beech or ash in reserve.

If the fireplace is used to help heat the home, the amount should be at least double: 7 to 10 loose cubic metres, said Thomas Goebel, managing director of the association of firewood suppliers in Berlin.

While firewood for occasional use can easily be purchased at a home supply store, consumers should regularly consider other sources. Local firewood dealers, organic material handlers and forestry associations are examples, said Herman Hansen of an association for sustainable raw materials in north-eastern Germany.

'Hardwood from deciduous trees is very well suited as firewood,' said Goebel. 'Beech has a fascinating flame, birch has the nicest aroma.' Such characteristics can be best appreciated when all the logs in the fire are the same type of wood.

The types of wood differ in the way they burn and the amount of heat they produce. Softwoods such as spruce and pine ignite faster and have a somewhat higher heat value than hardwoods of the same unit of weight, but they are less dense than hardwoods, said Florian Zormaier of the Bavarian regional office for forestry.

This means softwoods burn up faster but take up less room and new logs must be placed on the fire more frequently than when birch and oak are used.

'Softwoods also contain resin and they can splatter when they burn,' said Hansen. This dirties the glass panes of enclosed fireplaces and means the hot embers can be a fire hazard.

Hansen recommends using softwood as kindling. Small branches as thick as a finger are ideal for that purpose and cost less than artificial igniters. Hardwood is better for heating. The optimal length for a log is 25 to 33 centimetres depending on the size of the fireplace or stove, said Goebel. And it shouldn't have much moisture in it.

'The more water the wood contains, the greater the amount of energy that must be expended initially to evaporate the moisture,' said Zormaier. This energy does not disperse into the room and it takes much longer for the heating effect to begin.

Moisture in the wood also causes smoke, which can disturb neighbours and dirty the glass panes of stove doors, said Goebel. In the worst case moisture in the wood can damage the inside of the stove.

The experts recommend checking the wood's moisture content if possible. Consumers who buy large supplies of firewood must have suitable storage space for it. Ideal is an airy place protected from rain.

It's difficult to compare prices when it comes to firewood because it is sold in different units. Consumers who insist on comparing prices should rely on weight, but ensure that they are comparing the same type of wood and consider the moisture content, which adds weight.

Finally, some consumers might like to cut down a tree or two and chop their own wood. This requires the proper equipment and clothing and a certain amount of physical strength. And of course, permission from the forest owner.