Why burn dry wood?

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Why should we burn dry wood?

Nic Snell: Consider the heat energy created by the fire – the energy when burning dry wood is focused on creating heat, whilst the energy when burning wet wood is wasted boiling the water in the wood, rather than heating your room. So many people still think that we should not burn dry wood because ‘it burns too fast’. But on the contrary, the quicker burn means that there is more efficient use of the heat energy generated.

Many of us also ask the question as to how much is it to buy a ‘tonne’ of wood. With this moisture content in mind, consider the burn value of a tonne of wet logs versus a tonne of the same type of wood – but kiln dried to optimum burn levels. There is much more value to the wood that has been dried properly when you consider the wasted energy on burning wet logs. The wet logs are heavier, sure, but the quality for burning drastically reduces. Burning wet wood also results in poor quality combustion, increased smoke and the production of tars and creosotes that will damage your flue.

Whilst there is a very gradual move towards seeing wood sold by volume, there is still this strong ‘local’ supply of a ‘tonne of firewood’, or perhaps a ‘load of logs’. These phrases mean nothing unless you know some detail behind it such as what is the moisture content of the logs in the ‘load’, and what volume makes up the ‘load’?

Burning wet wood also results in poor quality combustion, increased smoke and the production of tars and creosotes that will damage your flue.

Firewood supply across the country is still very much a ‘cottage’ industry with thousands of local suppliers delivering to their customers who live just a few miles away. It is a great rural industry that provides work for many, and there is nothing better than getting that first load delivered in the autumn and getting it stacked away in preparation for winter. We anticipate those long evenings in front of a roaring log fire, reading the newspaper or watching a film, curtains drawn and the cat and dog lain sprawled in front of the wood burner! But what we need to be aware of is the quality of that ‘load’ of logs that we assume is ready to burn.

Research shows that firewood that is dried to below 20% moisture content will not only provide the most efficient burn but also provides the most heat output, ensuring your stove and chimney or flue have minimal soot, avoiding any tar build-up. Have you ever wondered why your stove glass perhaps goes black? It is almost certainly because your wood is not dry enough. The government, the stove industry, and log suppliers are keen to demonstrate how key burning good wood is to the environment, with some very simple changes making a major difference.

As the autumn approaches, it’s important we give a little more thought to buying that first load of firewood and perhaps start to ask some questions about the moisture content in that load.

Some simple questions to help are: