We all want to do our bit and help the environment. An easy way that we can do so is by using friendly energy sources. More and more consumers are turning to a sustainable source, being wood fuel. Wood burning is a brilliant environmentally sound option and for many more cost effective.
Kiln dried logs are the ideal choice and are perfect for all different types of wood burning. The main one everyone thinks about is winter burning in the stove, but they can also be used for pizza ovens, outdoor summer burning – in chimneas, fire pits or even a camp fire.
The benefits of kiln dried wood are vast:
- Generates a greater heat output
- An efficient fuel source with less smoke
- Economical and much easier to light
- Less smoke and ash means less stove and flue issues
There are two mains types of wood used as firewood fuel:
Typical hardwood fuel sources are that of Broadleaf, which is a slow growing deciduous, has a high density and burns slowly to produce a slower steady heat output.
Softwood is usually Conifers as these are the fastest growing evergreens. In comparison to hardwood though, they have a low density, burn much quicker which means that you will need much more of them and produce a higher heat output.
Although both types of wood have a similar calorific value per kilogram, the density of the softwood is approximately half that of hardwood. Therefore, you would need twice as much softwood to produce the same heat as hardwood!
The process of firewood seasoning for wood burning
When trees are felled or harvested, the wood naturally contains a high percentage of water. The reduction in this water is known as the process of ‘seasoning’. The term suggests that it would be for a period of time, and for natural air drying it would be around two years that is recommended.
Freshly cut wood can contain anything from 65 to 90 percent moisture. When kiln dried this normally reduces to less than 20 percent and often below 15 percent.
How energy efficient is your firewood
When you buy firewood, you should consider the cost per kilowatt of energy. You may have a local supplier that is convenient, but the firewood may be damp and difficult to burn.
Remember, the lower the moisture content then greater the heat output.
Wet or freshly cut wood has the highest moisture content and will produce one kilo watt hour per kilogram which can be compared to a single bar electric fire.
Semi dried logs (around 40 to 50 percent moisture) will produce three kilo watt hours per kilogram.
Kiln dried firewood (below 20 percent) will produce 4.5 kilo watt hours per kilogram.
Buying would by weight is effectively paying for water. Buy firewood by volume!
For some extra information, the higher water content will prevent the gases in the wood from igniting and allowing them to escape. This results in up to 50 percent potential heat wasted!
How efficient is your wood burning stove
Open fires have a strong attraction, however, they are considerably inefficient at heating compared to wood burning stoves.
An open fire with an open chimney is the least efficient. Next step would be a wood burner stove with an open chimney. They best is a high efficiency wood burner with an airflow control chimney.
A take home note:
The more efficiently a fire burns, the less fuel is therefore required and thus the least amount of carbon dioxide is produced.
So if efficiency is what you are after then you want to go with a high efficiency wood burner with airflow control.
Additionally, the more efficient kiln dried firewood produces less soot and tar and therefore helps keep your chimney clean and reduces the need for maintenance and cleaning.
How to store your firewood
The ideal way to store your firewood is in a dry airy location that is covered from the weather but allows plenty air flow.