MINNEAPOLIS – It’s the middle of another winter, temperatures are down, heating costs are up, and according to Mike Demchik, an agroforestry management educator with the University of Minnesota Extension Service, this is the perfect time to consider firewood as a heating option for next winter.
Many states are blessed with an abundance of sawmill and logging residue (called sawmill slabs and logging slash) as well as other sources of firewood.
Demchik believes using these residues can be a very effective way to heat your home.
Firewood is usually measured in firewood cords. A cord is a stack of wood 4 feet by 4 feet by 8 feet.
“Use caution when buying face cords or pickup loads because these measurements vary greatly,” Demchik said.
What it costs.
Depending on the type, quality and level of processing of the firewood, price for a cord can vary from $30 for unprocessed sawmill slabs up to $200 or more for cut, split and stacked stove length oak.
“Most vigorous, healthy people with basic equipment should be able to cut, split and stack a cord in six to eight hours,” Demchik said.
“Firewood requires at least a year to dry, so you should be cutting wood now for next year.”
How does wood stack up against other heating sources? Heating values are typically measured in million British Thermal Units, Demchik said.
Because different types of heating systems have different efficiencies, the numbers below are only an estimate.
Heating with wood.
Further, this winter has seen escalating prices for heating fuels, so these costs may not always represent actual heating costs.
Estimated approximate costs per million Btu for January 2001 are:
* Fuel oil (assuming a 65 percent efficient furnace and oil at $1.34 per gallon), $15.41.
* Gas (assuming a 70 percent efficient furnace and gas $1.13 per Therm), $16.14.
* Electric (assuming 100 efficiency and electric at 6.5 cents per kilowatt/hour), $19.05.
So how much is that wood worth? Demchik said hard maple and oak have about 23 million Btu per cord, woods like aspen and basswood average about 16 million Btu per cord and conifers like jack or red pine will be 12 million Btu or lower.
“However, furnace, wood stoves and fireplaces vary greatly in their efficiency,” he emphasizes.
Assuming 40 percent to 50 percent efficiency for a new, tight wood stove, a cord of oak could generate 9-11 million Btu, aspen 6-8 and pine 5-6.
So, compared to fuel oil, gas and electric, the energy in a cord of oak is worth about $150-$190, a cord of aspen/basswood is worth $105-$130 and a cord of pine is worth $80-$105.
“Heating with wood is much more labor intensive than oil, gas or electric,” Demchik said. “But if you have access to sawmill wastes or a woodlot, wood can save you money on your heating bills.”