Air VS Kiln Dried Firewood – which is best?

Date: January 21, 2022

We all know that it’s important that the logs you burn have a low moisture content. For this reason, stove manufactures recommend that your firewood is allowed to dry until it has a moisture content of less than 20%. There are two main ways that this is done, either air drying or kiln drying. But is air dried or kiln dried firewood better?

Why it's important to use dry firewood

If you try to burn wood that isn’t dry enough, not only will it burn badly, but it can be a serious safety hazard. Wet wood will  be difficult to light, and once lit it will not produce enough heat for your stove to get up to a good working temperature.

The wet logs will product loads of smoke and ash, and they can cause tar to build in your chimney.  At best this will mean that your chimney needs cleaning much more regularly, and at worst, this could result in a chimney fire.


Air Dried Logs (seasoning)

One way to dry firewood is to let it dry out naturally. Logs are left outside, and the sun and wind will slowly dry the logs out. Here in Scotland it can take a few years for logs to reach the magic 20% moisture level.

While this method is simple, it has some disadvantages. Since it can take several years for the logs to dry you need a lot of storage space. Not only will you need space for the logs that are seasoning, you’ll need space for the wood that is ready to burn. Unless you are lucky enough to have space to store several years of the wood fuel you need, this method of drying wood is probably not going to work for you.

If you have the space however, this is a cheap, easy way to dry your own wood.

Kiln dried firewood in bulk bags
Our Kiln Dried firewood ready to be delivered!

Kiln Dried firewood.

This method is much more common among commercial firewood providers and is the method we use at Pentland Biomass. Rather than allowing the wood to dry naturally, the logs are baked in a kiln until they are dry enough to burn in a stove

The big advantage of this method is that the logs are ready in a matter of days rather than years. It also means that when they are delivered to your door, they are ready to burn straight away.  

Since the wood has all been dried in a specialist kiln, you can also be sure that it has a consistently low moisture content, whereas air dried logs, especially if done yourself, can be a little bit more variable.

One of the concerns about kiln dried logs is that it takes energy to dry the logs, whereas if the logs are dried by the wind, less energy is needed. While this is true, the log kilns are often powered by waste woodchip that is created by cutting the logs in the first place, meaning that the energy used to dry the logs comes from a low carbon renewable source.

Which are better, Air or Kiln Dried logs?

As long as your wood is dried properly, it doesn’t matter how they have been dried!  Firewood will burn the same whether it has been air seasoned or dried in a kiln.

If you are cutting your own logs, you will almost certainly be air drying them, in which case we recommend you buy a moisture meter to check they are ready to burn. If you are buying your logs from a commercial provider such as us, they will probably be kiln dried.

Either way, as long as your wood moisture content is below 20%, the wood will burn well in your stove.

If you don’t have the space to dry your own logs, you can buy  our kiln dried firewood from our shop here!

© Pentland Biomass is a trading name of Pentland Plants Limited.
Company Number SC259669, registered in Scotland.
Our registered office is 6 Pentland Nurseries, Loanhead, EH20 9QG
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