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Heating with Firewood

Many West Virginia households rely on wood to provide local, sustainable, and cost effective heat during the winter. For the best results, homeowners need to select and prepare their wood carefully.

Selecting Firewood

Whether you are buying wood from a dealer or collecting firewood from your woodlot, the wood that is cheapest or easiest to obtain may not be the best choice for heating. The species and moisture content of the wood have a significant impact on the quality of the burn in your fireplace or woodstove.

The cord is the typical unit of purchased firewood. A cord is 128 cubic feet of air, bark, and wood. Typically, the wood is stacked 8 feet long by 4 feet high by 4 feet wide. Cords of wood can have different forms because some are wider, taller, square, or in line, but all must have 128 cubic feet of volume to be a cord. A 1,500-square foot home might burn four cords of seasoned wood in an average heating season.

While firewood often is measured by volume, this is not as important as the dry weight. The heavier and denser the wood is, the higher the heating value per unit. Oak and hickory are heavier woods with higher heating values. Lighter woods such as yellow poplar have lower heat output for the same volume of wood. Other characteristics such as ease of burning, ease of splitting, smoke production, and spark production also can be considered when selecting the best species to burn.

Seasoning Firewood

Firewood seasoning is another important step in preparing to use wood heat. Burning green wood, which can have up to 80 percent water by weight, requires evaporating all the water from the fuel, stealing up to 15 percent of the potential heat. Using green wood can also lead to creosote buildup, which can lead to destructive chimney fires.

The easiest way to season your wood is to let it air-dry naturally. Split wood dries faster than roundwood, so to minimize drying time make sure it is split soon after it is cut. Wood should be stacked off the ground and not directly against any structure.

The wood will be ready to burn after it is fully seasoned or the moisture of the wood is down to less than 20 percent. This generally takes from six months to more than a year, depending on the weather, type of wood, and how the wood is stored.

seasoned firewood vs. unseasoned firewood.

One way to check your wood is to look for cracking on the ends of the split wood, which indicates that at least the ends are dry. Another method involves knocking two pieces together; if dry, they will create a sharp cracking noise, but wet pieces will create a dull thud.

Always buy firewood locally because transporting firewood promotes the spread of emerald ash borer and other forest pests. These pests can be fatal to individual trees and whole forests.

Author: Ben Spong, Forest Operations Extension Specialist, WVU Extension Service
Last Reviewed: May 23, 2017