Tarm Biomass sells a broad mix of heating boilers that use diverse forms of wood fuel.
We decided to make a simple wood fuel guide that contains frequently asked questions about wood energy. To start with, wood energy is measured in British Thermal Units or BTUs. A BTU is the amount of energy required to raise 1 pound of water by 1 degree Fahrenheit.
Energy per cord of wood:
-The average mixed northern hardwood cord contains 24,000,000 BTUs.
-The average coniferous (soft) wood cord contains 18,000,000 BTUs.
Energy per ton of pellets:
-Wood pellets contain 16,000,000 BTUs* (about 115 gallons of #2 heating oil or 170 gallons of LP).
Energy per ton of wood chips:
-Green wood chips contain 8,000,000 BTUs.
-25% moisture content wood chips contain 11,500,000 BTUs.
Weights:
-A cord of green hardwood weighs about 4,500 pounds.
-An air-dried cord of hardwood weighs about 3,500 pounds (The difference equals approximately 125 gallons of water!).
Wood Fuel Space requirements/volume:
-A cord is a stack of wood 4' x 4' x 8' or 128 cubic feet (pulp cord).
-A face cord is a stack of wood 4' x 8' x the length of the firewood.
-There are 3 face cords of 16" long firewood in a pulp cord.
-A long bed pickup truck holds approximately 1/2 pulp cords.
-One ton of pellets fits in 50 cubic feet or about a space 4' x 4' x 3' (a 40-pound bag of wood pellets holds 1 cubic foot of pellets).
-One ton of 25% moisture content wood chips fits in about 135 cubic feet.
-One ton of green wood chips fits in about 100 cubic feet.
#2 Heating Oil and Propane equivalents:
-Average mixed northern hardwood - approximately 170 gallons of oil or 260 gallons of propane.
-One ton of wood pellets - approximately 115 gallons of oil or 170 gallons of propane.
-One ton of dry wood chips - approximately 80 gallons of oil or 125 gallons of propane.
-One ton of green wood chips - approximately 60 gallons of oil or 85 gallons of propane.
-One BTU is equivalent to 3414 kW.
-A cord of red oak contains approximately 5760 Kilowatt-hours of energy or about ½ of the total electric power an average American residence uses in a year.
While not applicable to all areas of the country due to regional tree species, this is a great resource for firewood information from the University of Nebraska: https://outreach.cnr.ncsu.edu/ncwood/documents/NebraskaFirewoodGuide.pdf
*A United States ton (short ton) weighs 2,000 pounds.
