Efficiency – make the most of your firewood

It's important that you always use dry firewood in your wood burning stove. If you use moist firewood, you won't reach maximum efficiency and heat - that's a waste of money. Read more about why you should always use dry firewood and why this is the most eco-friendly solution.

Author: Line Nederby
Published: 15. October 2015
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How to make the most out of your firewood

A wood burning stove’s efficiency is defined by how much heat you get out of your firewood. Naturally, you want maximum efficiency from the firewood that you have spent time and money on. The most important factors for a high efficiency are

  • lighting a fire using dry firewood
  • lighting a fire in a wood burning stove whose design, structure and technique have been developed to make the most out of your firewood
  • lighting a fire correctly

Optimise the use of your wood burning stove

– use dry firewood

If you light a fire using firewood that has a moisture content above 18 %, the efficiency of the firewood will decrease drastically. This happens due to an incomplete combustion of the wood’s gases and heat loss in the chimney. Wet firewood simply reduces the efficiency. The reason why is that if firewood is wet much of the heat will be used to boil off the water content of the firewood. This means the heat will be so weak that you won’t make the most out of your firewood or of your wood burning stove.

When you light a fire using wet firewood…

  • you won’t reach the optimal temperature and combustion in your wood burning stove
  • the gases in the firewood won’t be burnt
  • the heat you will get out of your firewood will be minimal
  • the energy will disappear up the chimney as smoke
  • you’ll pollute the environment

By lighting a fire using dry firewood and by correctly lighting the fire and having the right combustion, you will reduce the heat loss as much as possible.

Here you can read more about tests which show what happens when you light a fire using wet firewood.

Read more about lighting a fire correctly

How do you know that your firewood is dry?

Did you know…

One kilogram of dry firewood (moisture content below 18 %) contains 5.32 kWh of energy no matter the type of wood. (The only exceptions are birch bark and twigs which give off 20 % more. (Source: Lars Mytting’s book Solid Wood)

In practice, 1 kilogram of firewood will give off less, corresponding to 3.5 kWh per kilogram of firewood. The loss happens because of the moisture content and because the wood burning stove is not capable of using the firewood completely.

Read more about drying wood

It’ll often pay off to buy a new wood burning stove

The difference between the heat that you’ll get out of an old and a new wood burning stove is big. Old wood burning stoves usually have an efficiency of about 40-60 % while a new wood burning stove has an efficiency of about 75-80 %. An open fireplace can have as little as a 10-15 % efficiency. (Source: Lars Mytting’s book Solid Wood)

A modern wood burning stove will release half as many particles as an old wood burning stove – thanks to the producers’ product development. Tests from the Danish Technological Institute show that for the past 10-12 years the particle emissions have been reduced by 60 %. Furthermore, the amount of firewood that a modern wood burning stove uses is 40-50 % less than the amount an old wood burning stove uses.

When you buy a modern wood burning stove with an automatic control device that regulates the air supply, there is a good chance that you’re making the most out of your wood burning stove. And you’ll use less firewood this way.

The difference between the optimal and the non-optimal use of you wood burning stove can amount to a difference of 25-40 % in the use of firewood.

Wood burning stoves are an eco-friendly source of heating


It won't pollute nature when you use your wood burning stove - as long as you fire correctly and always use dry firewood. Read more about why firing with firewood is carbon neutral.

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Eco-friendly combustion with correct air supply


Air supply is one of the most important factors when it comes to firing in a correct and eco-friendly way. Therefore it's good to know a little about using your wood burning stove's air inlet controls correctly - this way you'll get optimal and complete combustion.

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How to light a fire correctly in your wood burning stove


It's important to light a fire in your wood burning stove correctly. This way you'll make the most of your firewood and you'll protect the environment as much as possible.

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