How to maximise the efficiency of burning wood
Burning wood can actually have a lower environmental CO2 impact than if it was left to rot naturally.
Wood is a highly sustainable, versatile energy source. If sourced from managed woodlands, burning wood on a high efficiency wood burning stove can actually have a lower environmental CO2 impact than if it was left to rot naturally. This fact often surprises people but it does easily explain the role that burning wood can play in a sustainable, more environmentally-friendly future.
Managed woodlands: Unlike fossil fuels, which are a depleting resource, trees are continually growing. A hardwood forest will grow about 7 tonnes of new wood a year per hectare, and even more for faster growing soft-wood. There are over 3 million hectares of woodlands in the UK, so it is easy to see how much more sustainable wood is as an energy source than fossil fuels.
The best way to burn wood
Wood is something that is burnt on a traditional open fire… Or is it? The best way to burn wood is actually on a high efficiency wood burning stove. Manufacturers like Charlton & Jenrick have stoves in their range that have an efficiency of over 80%. This means over 80% of the heat a stove produces goes directly on heating a room. By comparison, an open fire has an efficiency of only around 20%. That means around 80% of the heat is wasted, disappearing up the chimney! A high efficiency stove cleanly burns less wood, producing the same heat output.
How to maximise the efficiency of wood burning
To achieve the maximum efficiency and sustainability associated with burning wood, you should follow these guidelines:
Burn seasoned wood: Wood with a moisture content above 25% will not burn as efficiently as wood that is correctly seasoned. Burning wood in a stove that is not seasoned will increase the chances of carbon monoxide poisoning, it will produce a poor flame output and increase congestion in a flue, which can also increase the changes of a chimney fire.
Never burn painted or treated wood: Burning wood that has been painted or treated – such as with decking can create toxic gases and congestion in a flue.
Burn hard wood: Hard wood (eg. Oak) is the most efficient type of wood to burn as it lasts longer and produces a good heat output.
The best woods to burn:
Oak – Burns longer and produces a good heat output.
Ash – Ash is thought to be one of the very best woods for burning. Ash creates a steady flame and a good heat output. Unlike other wood, ash can be burnt when green, but like with most wood burns at its very best when it is dry.
Beech – Like ash, beech burns very well. However, it does not burn well when green due to its much higher moisture content when live. Beech can be identified by its pale cream colour with a pink or brown hue.
Hawthorn – This type of wood has a slow burn rate, and a good heat output.
Rowan – Similar to hawthorn, rowan has a very good heat output that burns slowly. Rowan is also known as Mountain Ash.
Thorn – Thorn produces very little smoke, which makes it an ideal wood where excessive smoke could be an issue. It also is considered a very good wood as it has a slow burn and produces a good level of heat.
Yew – Slow burn and produces a great, intense heat. Burning yew also produces a pleasant scent, which makes it stand out a little more over other woods.
Article accurate at time of publishing, December 2016.
Words: Rob Morgan at Charlton & Jenrick