Wood burns much more efficiently and provides much more heat when it is dry. By kiln drying our logs in our wood fired kilns, we are ensuring the moisture content of the wood reaches a level that provides a very clean, hot burn.
Unseasoned wood is wood that has not had any of its natural water content removed. By seasoning wood, you are allowing this natural water content to evaporate from the log over a period of time. For most wood, this seasoning process takes up to two years. This is why much of the firewood available as being seasoned and ready to burn straight away has not had the time to reach a moisture content low enough to burn efficiently before being sold.
Burning wood that is unseasoned or that still has a high water content is both inefficient and costly. To produce a nice hot fire, wood needs to be dry and if its not, it can not burn properly. The heat that is produced is minimal and is used to then boil the water in the log away before it will burn. This means much of the heat produced from the fire is disappearing up the chimney or flue as steam. As it doesn’t burn as hot, you will need up to 3 times as much wood to get the same amount of heat as you would from good quality kiln dried logs.
Not only do you have the added cost of buying more wood to get the same amount of heat as kiln dried wood, you are also producing more smoke. This smoke causes a greater build up of soot and tar in your chimney or flue, making your stove or fire burn wood less efficiently, but more importantly this can cause a potential fire hazard through increasing the risk of a chimney fire through the build of up soot and tar catching alight inside your chimney or flue.