A study by the consumer guide Which? Has shown that the majority of wood burning stove owners are not getting the very best out of their investment, as they are burning the wrong type of fuel. We’ve prepared a short guide to getting the very most heat output out of your fuel in order to then get the most value for your money.
There’s other benefits to burning the correct fuel for your wood burning stove as well – other than saving money, you’ll be looking at a much higher heat output (and a warmer house), a safer burn with minimal chances of buildup in your chimney, as well as the knowledge that by doing it right, you’re prolonging the lifetime of your wood burning stove and doing all you can to avoid costly repairs and replacements.
Most people tend to use seasoned logs on their multifuel or wood burning stoves. Figures obtained by Which? Indicate that the majority of wood burning stove owners do seem to think that seasoned logs are the way forward in all circumstances, but really, any kind of non-chemically treated wood, as long as it has a moisture content of less than 20%, is more than fine. Getting a moisture tester is very worthwhile. They’re very inexpensive, and they can indicate when your wood is ready to give an optimal burn.
It might surprise you to learn that seasoned logs contain 40% – 25% moisture. Because of that, you’re only really looking at an average heat output of 3kWh per kilogram of seasoned wood – the wasted heat output of seasoned wood is pretty drastic, and spells bad news for your stove over time due to the fact it is having to burn all of this moisture first.
An alternative is briquettes, which typically contain less than 10% moisture due to the fact that a briquette is pulped paper or wood. Typical heat output on briquettes is 5kW per kilogram, which makes them highly more efficient than seasoned wood. However, the typical cost of briquettes can be much higher than seasoned wood.
There is a happy medium between the expense of briquettes and the inefficiency of seasoned logs. Free wood or kiln dried logs are more than acceptable alternatives – as long as they contain less than 20% moisture content. Kiln dried logs have shown that they denote a heat output which is significantly higher than that of seasoned wood – 4.5kWh per kilogram, and are not as expensive as briquettes.