Heat Content of Types of Firewood

Heat content, measured in BTU, will vary between woods of different density and water content.

Heat Content

The official measure for the heat, or energy, content of wood is BTU (British Thermal Units). Every type of wood will produce a different BTU when burned.

Density

Hardwoods, wood with a thicker density, will burn at high temperatures for a longer period of time. Softwoods, wood with a lighter density, will quickly catch fire but burn away faster.

Hardwood

Hickory, beech, oak, ash, and walnut are common examples of hardwoods used with indoor furnaces. Hardwoods are recommended for the bulk of winter firewood supplies.

Softwood

Fir and pine are common types of softwoods used for burning. This wood should be reserved for kindling because it burns quickly and will leave creosote deposits in chimneys.

Seasoned

The best wood is always seasoned. Seasoned wood is wood that has been dried out to a gray or dark color for at least six months to a year. This wood burns best because it has lost some of its water content.

Heat Content of Common Trees

Per cord of dried hardwood, bitternut hickory produces 29,200 BTU, red oak 23,700 BTU, red maple 24,000 BTU and black cherry 23,500 BTU. Softwoods such as white pine at 17,100 BTU and balsam fir at 15,500 BTU produce less heat energy per cord.

References

• Woodheat.org
• Alternative-Heating-Info.com