Firewood Facts

Measurement of Wood

A standard cord of wood has a volume of 128 cubic feet and is 4 feet high, 4 feet wide and 8 feet long. Face cords, or short cords, do not have standard measurements and volumes cannot be determined; thus this term should not be used to purchase wood.

Heating Value of Wood

When burning wood it is essential to have the wood as dry as possible in order to produce more heat per pound of fuel, thereby obtaining a higher heat value and also reducing trouble with creosote.

Air-dried wood contains approximately 20% moisture and will yield about 5,800 BTU's per pound. Green wood containing about 60% moisture will yield only 4,100 BTU's per pound. The heavier the weight of dry wood, the more BTU's per cord.

Seasoning Wood

Wood is considered seasoned when the moisture content is 20%. The diameter makes a big difference with respect to drying. To ensure uniform rapid seasoning, pieces over 8" should be split once and those pieces over 12" should be quartered. Wood cut during the fall and winter and piled in the open should be well-seasoned and ready for burning the following winter. Unsplit wood requires 9 to 12 months to season thoroughly. The moisture content of split wood will be reduced to about 35% in three months' time, if dried during the late spring and summer months. This wood has 86 to 90% as much heating value as wood of the same species that is thoroughly seasoned. Fresh cut wood has a heating value of around 70% of that of seasoned wood.

Therefore the value of thoroughly seasoned wood will offer significantly greater heating value.