Anyone who heats with wood knows this well: not all firewood is the same. Choosing the right species and recognising those that are less suitable means more heat, less smoke and cleaner combustion.
Not all logs burn in the same way: some provide long-lasting heat and compact embers, while others burn quickly and produce excessive smoke.
Why doesn’t all wood burn the same way?
The performance of firewood depends mainly on three factors: density, moisture content and seasoning.
Dense woods contain more energy and burn slowly, producing durable embers. Lighter woods, on the other hand, burn faster and release less heat.
The calorific value of wood
The calorific value indicates how much energy is released during combustion. Hardwoods such as oak and hornbeam have very high calorific values due to their compact structure.
This means they burn longer and require fewer refills.
Dry vs damp wood: a crucial difference
Another key point is the moisture content.
When wood is too damp, part of the combustion energy is used to evaporate the water inside it. The result: more smoke, less heat and increased deposits inside the chimney.
For efficient combustion, wood should have a moisture content below 20%, achieved through proper seasoning. European technical standards for solid biofuels, including ISO 17225-5, classify firewood based on moisture content and material quality.
Which wood produces the most heat?
When it comes to home heating, some species are actually more suitable than other.
Hornbeam
It is one of the top-rated among all. Very dense and heavy, with a high calorific value and long-lasting embers. It burns evenly and without sparks.
Oak
Both common oak and durmast oak burn slowly and produce compact, long-lasting embers. Ideal for maintaining constant heat for many hours.
Beech
A well-balanced wood: easy to ignite, stable flame and low smoke production.
Beech or hornbeam: which should you choose?
Both are excellent options, but with different strengths.
Hornbeam is denser and provides longer-lasting embers; beech ignites more easily and produces less ash.
Many people choose to start the fire with beech and then continue with hornbeam or oak.
Woods to avoid
Not all wood types are suitable for home heating: some achieve lower performances, although they are cheaper and easier to find.
Low-calorific woods
Such as poplar, willow and lime are very light and burn quickly with little heat output.
Many conifers, i.e. spine, fir and other resinous woods ignite easily but do not maintain heat for long.
Wood that clogs the flue
Wood that is rich in resin or too damp produces more smoke and promotes creosote buildup in a chimney. Always use well-seasoned wood, especially with modern appliances certified for the highest Environmental Performance Standards.
Wood that should NEVER be burned
A fireplace is not an incinerator. It should be never used for burning:
- painted or treated wood
- industrial panels or chipboard
- plastics or waste materials
These materials release toxic substances and can damage the appliance.
How to store firewood correctly
Good combustion starts long before lighting the fire. Wood should be best seasoned for 12 to 24 months and stored while :
- raised off the ground
- well ventilated from the sides
- covered only on the top
The air and the sun will do the rest
The charm of firewood: from heating to cooking
A wood fire is not only a source of heat but also an essential element in traditional cooking.
The same woods used for home heating can provide perfect embers for grilling, wood-fired baking or outdoor cooking to recover and share authentic flavours.
Frequently asked questions on firewood
Dense hardwoods such as hornbeam, oak and beech generally have the highest calorific value. They produce compact, slow-burning embers and keep a fire place or stove hot for a longer time.
Light woods such as poplar, willow or lime produce less heat and burn out more quickly, because of their low density. They are not really dangerous, but they need to be used more often than hardwoods to feed fire.
Wood should be seasoned for 12–24 months to achieve efficient combustion, until it reaches a moisture content below 20% – which is ideal to produce plain heat and less smoke.
When the wood is too damp, part of the fire’s energy is used to dry moisture out of it, resulting in more smoke, less heat and more deposits in the chimney.
When burning, resinous or damp woods (pine, fir, fresh-cut wood) promote creosote formation in the chimney, which demands maintenance more often.
