Page 46

2016 11 02 Broschure 52s

Firewood Softwood - pinewood Softwoods have a low density. They therefore catch fire easily and are well suited for kindling. Among the softwoods, which are resin rich, Spruce is the one best suited for stoves. As the resin melts it blocks the water channels in the wood and it cracks. This romantic crackling lends an unbeatable charme. Pine is less suitable because the high tar content can cause sooting. Hardwood from broad-leafed trees Hardwoods have a high density and thus a higher heat energy per voulume unit. Beech has an attractive fire and gives a long lasting heat without shooting sparks. The generous embers are a good bed for adding fresh wood. Oak has a less attractive fire and is therefore better used for central heating or stoves without a view of the fire. Birch is very popular, it does not shoot sparks and its ethereous oils burn with an attractive blue flame with a pleasant odor. Birch is decorative next to the stove and the bark is an excellent starter. What you should know Heat energy *) Density Heat energy *) heat energy kWh/kg kg/dm³ kWh/dm³ after loss of ca. Spruce 4,3 0,44 1,9 1kWh needed to Beech 4,2 0,74 3,1 evaporate water Oak 4,2 0,69 2,9 bound in the wood Birch 4,2 0,68 2,8 What is stere or a stacked cubic metre? By definition 1 stere is 1 m³ stacked, freshly cut wood inclusive the space between the billets, corresponding to 0,7 m³ solid, fresh wood. Freshly cut from the forest, the wood has 50% water content. Air dried firewood should not have more than 20%. Thus 1 stere corresponds to 0,6 m³ dry firewood. For comparison; 1 stere beechwood has ca. 1900 kWh heat energy, the same as 190 liters domestic fuel oil. How much firewood do I need? For a cosy evening in front of the fire you typically need 7 kg, almost 10 dm³ beechwood and a little spruce kindling to start the fire. 1 stere has 600 dm³ firewood, so with 1 stere you could theoretical spend 60 nice fireside evenings. With 2-3 stere beech and ½ stere spruce you should be comfortable for one winter. However, other factors play a role, espescially the output of your stove and the heating hours. These in turn are driven by how well your house is insulated, how cold is the winter, etc.. To find your optimal amount of wood, it is a question of trial and error. Take care when buying firewood You should only fire your stove with dried firewood with maximum 20% water content. The wood must have a natural finish, no paints or varnish and absolutely no impregnated material. Both beech and spruce will normally dry to less than 20% water content in one year, providing proper storage. Round, unsplit wood requires 2 years to reach the same dryness. Wood with fungal decay indicates a poor storage causing reduced heat energy. Humid wood can cause higher emissions and leave deposits in the stove and chimney. Correct storage of firewood The ideal storeage place is sunny and exposed to wind. Take care that the ground is dry with a good ventialtion, also at the back. Leave some distance to the house wall. Put a rain cover on top, but do not wrap the stack in a plastic cover. By storage in the cellar, leave a window open. www.red-anvil.net 46


2016 11 02 Broschure 52s
To see the actual publication please follow the link above