Using wood

Press, 15 June 1983, Page 27

Using wood

The cost of wood for fuel can be significantly reduced by buying in summer, when it is at least part of the way to being "seasoned.” When wood is sold by weight, buying during the winter months can mean that a lot of money is spent on unwanted water.

In addition, the burning of wet wood uses up heat to drive moisture out of the wood before it will burn. Green firewood can hold up to half its weight in water which has to be driven off as steam before the wood can burn, and this uses up heat which could otherwise be providing household warmth.

Freshly cut timber needs at least 12 months to season properly, and even then, it still contains 20 per cent moisture. This level is hard to reduce unless the wood is further dried in a kiln. Unseasoned wood ,can also lead to lower fire temperatures and the formation of creosote, or soot, in the

chimney or flue, as the water vapour and any unburned, volatile gases condense.

Chimneys and flues need to be kept clean to avoid the risk of a chimney fire, so it is unwise to burn either wet wood or rubbish in a space heater. Note (advice from Consumer 204, April 1983): It is better to buy a woodburner that is too small for your requirements, rather than one that is too big. Apart from the wastage of heat, you will be tempted to operate a too powerful heater at a slow rate. This will cause lower temperatures and your flue will soon be blocked with creosote.

Hints: When you light the fire, leave the air controls open until the flames have fully caught hold, the firebox and the flue are both hot, and the wood is starting to char.

Shutting the controls down too soon creates a smoky, inefficient fire, as the temperature is not high enough for the gases to burn.

When refuelling the fire,

leave the air control open for a few minutes until the logs are well ablaze. Too much wood in the fireblox lowers the heat and creates a smoky fire. A

small fire regularly fed is better than a lot of wood at low output. Do not burn an enclosed fire with the heater door open, as the fire is likely to

overheat. Fully open all air controls before you open the heater door ... then open the door slowly. This will avoid smoke being blown back

into the room. Check your flue at least once a month and have it cleaned if there is any sign of creosote build-up or quantities of soot.