Facts About Heating with Wood

Wood is the only fuel that heats twice ...
first when you cut and stack it, and again when you burn it!

A cord is a stack of wood 4 feet high, 4 feet wide and 8 feet long. Allowing for air pockets, a cord is approximately 85 cubic feet of wood.

On average, a pound of wood produces 8,600 BTUs of heat, regardless of species. So dense heavy woods deliver more heat per cord. Consider this fact when comparing prices for different kinds of wood.

It takes about 1,000 BTUs to evaporate each pound of moisture in a log. That is why dry wood produces less creosote and 10-30% more useable heat for your home.

A good time to cut or buy green wood is in late winter or early spring. To dry it as quickly as possible, cut it to length and stack it so that air can circulate through the pile. Also, shelter the stack from the weather and hold it for 18 months before using.

If you cut your trees in the spring or summer, let them lie "unlimbed" until the leaves wither. The withering process draws moisture from the wood. Then, cut the wood to the longest length that will fit in the firebox. The longer the stick, the longer the fire will hold.

The amount of heat extracted from a cord of wood varies with the species. The U.S. Forest Products Laboratory compiled the following figures, showing weights and energy content for various species of wood. These figures assume seasoned wood with 20% moisture content.

Wood Species Cord Weight (lbs) Energy Content (million BTUs/cord)
Alder 2,70817.6
Apple 4,14026.5
Ash, Black 2,992 19.1
Ash, White 3,689 23.6
Aspen 2,295 14.7
Basswood 2,108 13.5
Beech, Blue 3,890 26.8
Beech, High 3,757 24.0
Birch, Black 3,890 26.8
Birch, Gray 3,179 20.3
Birch, Paper 3,179 20.3
Birch, White 3,179 20.3
Birch, Yellow 3,689 23.6
Box Elder 2,797 17.9
Butternut 2,100 14.5
Cedar, White 1,913 12.2
Cherry 3,120 20.0
Cherry, Black 2.880 19.9
Cottonwood 2,108 13.5
Elm, American 3,052 19.5
Elm, Oyen 3,052 19.5
Elm, White 3,052 19.5
Fir, Balsam 2,236 14.3
Fir, Douglas 3,196 20.6
Hackberry 3,246 20.8
Hemlock 2,482 15.9
Hickory 4,327 27.7
Hornbeam, Eastern 4,267 27.3
Locust, Black 3,890 26.8
Maple, Red 2,924 18.7
Maple, Sugar 3,757 24.0
Oak, Red 3,757 24.0
Oak, White 4.012 25.7
Pine, Jack 2,669 17.1
Pine, Norway 2,669 17.1
Pine, Pitch 2,669 17.1
Pine, Ponderosa 2,380 15.2
Pine, Western 2,236 14.3
Spruce 2,100 14.5
Spruce, Black 2,482 15.9
Tamarack 3,247 20.8