Checking the moisture content of firewood is critical because it directly affects its burning performance. Higher moisture content results in more difficult ignition, reduced heat output, and increased smoke production.
On the other hand, lower moisture content promotes efficient combustion, higher heat output, and cleaner burning. Achieving and maintaining the correct moisture content in firewood is essential for optimal combustion efficiency, heat production, and minimizing environmental impact.
The Importance of Firewood Moisture Content
To ensure proper combustion, a moisture content of less than 20% is required, which is what you see with the moisture content of kiln dried logs. As the moisture content rises above 20%, it becomes increasingly difficult to burn the wood effectively.
It is also important to note that firewood can dry out too much. If the moisture content is too low, the wood will burn too quickly, leaving less heat energy behind. Therefore, it is important to find the right balance of dryness to ensure optimal burning.
Many fireplace and wood stove problems can be caused by burning wood with high moisture content. Read the manufacturer's instructions for your stove or fireplace. This can result in difficulty lighting the fire, poor burning efficiency, lack of heat, and smoke production. In addition, burning wet wood may result in loud noises such as hissing or spitting as the fire works to remove the moisture.
Wood Harvesting
The amount of moisture in wood can vary depending on when it is harvested. Wood harvested in the winter often has a lower moisture content than wood harvested in the spring. This is important because the ideal moisture content for firewood is less than 20% if it is to burn efficiently. This is typically the kiln dried moisture content that we find in store bought lumber.
To reach this moisture content, the wood must go through the process of seasoning, which helps to dry out the wood. If the moisture content of the firewood is higher when it is cut, it will take longer to dry to a level where it can be used as firewood. To speed up the seasoning process, it is best to cut wood when it has the lowest possible moisture content.
Please note that seasoning wood can take a considerable amount of time. Hardwoods can take up to 2 years to become dry enough for use, while softwoods can take up to a year to dry out.