Raw logs do not burn well, so it is better to buy them already dry. If it is found that they are wet, you should deal with their drying. It all depends on when the logs have been harvested. Firewood harvested in winter dries for 5-6 months, while summer firewood dries for up to 10 months. Timber harvested in the spring or fall dries the longest. Just cut wood has a moisture content of 60-80%. After the branches are removed, the trunks are dried for about a year. During this time, the humidity is reduced to 40-50%. The material becomes lighter, it is removed from the plots. At the site the wood is sawn into billets and then cut. The wood in the stack is blown by the wind, and the humidity is reduced to 35-45%. These are logs of natural humidity. They are so called because no drying chambers are used for drying.

   If you compare the chemical composition of different types of wood, you will see that it is about the same. When burning 1 kg of wood of different species, heat is released (kcal/kg): conifers - 4560; mixed - 4510; deciduous - 460. For furnace firing hardwoods are better suited. They have a denser structural structure. This significantly increases the burning time with a constantly high energy output.

Birch and aspen Birch burns well, gives a lot of heat. There is no soot when it burns. Aspen gives off a pleasant fragrance when burning, it is used to fire the sauna. Birch and aspen firewood dries quickly, enough 3-6 months. If you put a few logs near the stove, they dry up in 1-2 weeks. Apricot In combustion emits the aroma of almonds. The flame is even, there is no crackling or sparks. No soot is formed. Harvested firewood reaches 20% moisture content in 8 months. Oak and pine Oak wood emits an aroma of the forest when burning. Oak firewood is bought for kindling fireplaces. For sauna stoves, pine is used more often. When it burns, the flame is bright, but it produces a lot of soot. Oak and pine wood dries more slowly than birch wood. Under natural conditions, it will take 8-12 months.

Source: https://stroy-banya.com/banshikam/skolko-sohnut-kolotye-drova.html