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Kiln Dried Wood: Explained!

Kiln Dried Wood: Explained!

Posted on 3 May 2019 By Coal Hut

In another blog, we discussed the process of seasoning your own wood. And, although possible, many of our customers just don’t have that free time to waste. Luckily, there’s a faster, more efficient way: kiln drying! In this post, Coal Hut is taking a deep-dive into kiln dried wood. We’ll cover everything from the importance of wood moisture content, the kiln drying process and so much more. Read more to find out how to get industry-leading kiln dried wood at

Green vs dry wood

Once hardwood logs have been harvested, they are classed as ‘green’. This refers to the moisture content currently held in the wood itself. ‘Green’ wood is typically made up of more than 60% water. These moisture levels make for unfavourable burning conditions in the likes of stoves and closed appliances, making the firewood difficult to light and causing it to produce excess smoke and low heat output.

In order to obtain dry, easy-to-light firewood, the first option available would be to season your own wood. This involves leaving wood logs in a sheltered area outside for an extended period of time. Though it may seem relatively easy to do, it can be a time-consuming and arduous process - wood seasoning can take from 6 months to a year! But there’s a simpler way.

What is kiln drying?

Kiln drying is the process of heating wood logs in purpose-built kilns to a point where their excess moisture levels are evaporated, thus speeding up the seasoning process and achieving a better overall end product. Optimal moisture levels for home fire fuel are from 20% and below, and the kiln drying process simultaneously burns off any impurities taking up by the wood in nature.

The kiln drying process

From the moment trees are harvested, they are first brought to a wood mill where they are debarked and sorted into their relative types, sizes and shapes. This is an important step in the kiln drying process as logs that are grouped together in similar sizes will be dried to equal moisture levels.

Once grouped, the wood is then passed in batches through to the kilns made up of four compartments, namely: the chamber, the heat exchanger, the ventilation system and the air fans.

  • Chamber - Typically constructed in brick or cement, the chamber provides the housing for wood batches that are to be heated. Modern kilns, however, are tending towards newer materials, such as aluminium, glass and polyurethane foam.
  • Heat exchanger - Heat is passed into the chamber either by steam heat exchangers or through traditional furnaces which pass gases through large flue pipes.
  • Ventilation system - The goal of the ventilation system is to control humidification levels in the chamber and extract any water that has evaporated from the wood logs during the heating process.
  • Air fans - These fans are responsible for both the transfer of heat and evaporated water in the chamber. Air fans are typically fixed to the inside of the chamber itself.

Once the wood has achieved the optimal moisture levels of below 20%, it will often be transferred to a planer to be cut into specific sizes according to the appliances in which it will be used.

Kiln dried wood at

Coal Hut offers the highest quality Kiln Dried Hardwood Logs for use in wood-burning stoves and other closed appliances. To make things easier for you, they are pre-split into convenient lengths that make for easy stacking and cleaning. Our customers love how easy they are to light, not to mention the warm and inviting flame that they produce.

But that’s not all! At, you can take your pick from a range of heat logs, wood pellets and lignite briquettes that perform to the same high standard. And if you’re on the search for coal or smokeless fuel, we’ve got that too! Order online today for fast UK delivery