For More Information Wood is a source of heat currently used by many Nebraskans, and more firewood likely will be burned as the cost of other energy sources, such as gas and electricity, rises. In order to use firewood effectively, an understanding of species' characteristics and firewood volumes is needed. Species Characteristics Firewood from different species or types of trees varies widely in heat content, burning characteristics and overall quality. I below presents several important burning characteristics for most species used in Nebraska.
Green weight is the weight of a cord of freshly cut wood before drying.
Dry weight is the weight of a cord after air drying. Green firewood may contain 50 percent or more water by weight. Green wood produces less heat because heat must be used to boil off this water before combustion can occur. Green wood also produces more smoke and creosote than dry wood. Firewood always should be purchased dry or allowed to dry before burning.