Firewood specific weight: cubic meter weight by wood species

The transition to alternative energy sources makes us pay attention to wood. This is what our ancestors used for heating homes and cooking food. Stoves, fireplaces and solid-fuel boilers all require wood, namely firewood. But all plants are different, and trees, having different structure and chemical composition, differ in characteristics such as calorific value, weight, density and moisture content.

How Much Does Firewood Weigh?

How can the weight of 1 cubic meter of firewood be determined? Does it matter whether the firewood is freshly cut or dried? Knowledge of specific weight, moisture content and other wood features helps answer these questions.

More than 200 species of trees and shrubs grow in our region. They all burn differently: some faster, some slower; some release a lot of heat, while others release less. When choosing wood for heating, it is better to focus on medium-aged trees and avoid wood that is too young or too old. Such wood burns the longest and releases the most heat.

The amount of released heat also directly depends on density and dryness of the firewood. Wood with a moisture level of 15-20% is considered the most suitable for the stove, while a freshly cut tree contains at least 50% moisture. Part of the heat will be spent evaporating water, so the efficiency of wet firewood is much lower. Dry firewood also weighs much less than wet firewood.

Wood weight depends on:

• the structure of wood cells and their moisture content;

• wood density;

• the part of the plant: the heaviest parts are branches, the lightest part is the base of the trunk;

• salt and resin content.

Firewood weight can be determined empirically: weigh a small piece of wood of known volume and calculate its density as the ratio of mass to volume. But this procedure is not always convenient in practice.

Tables of average wood weight values help simplify calculations. The values are given conditionally for material with 15-20% moisture content. Interestingly, a change in wood moisture does not change its density, although it strongly affects the specific weight value.

What Firewood Is Best for Heating?

Oak firewood is considered optimal in terms of calorific value, followed by birch, aspen and pine.

• Oak contains little resin and produces dense, long-burning firewood with high heat output. Any firewood should be burned only with proper draft and ventilation, because incomplete combustion produces dangerous carbon monoxide.

• Birch firewood burns long and evenly, but contains many resinous substances and deposits soot in the chimney.

• Coniferous species are also used less often because of their high resin content.

• Poplar firewood is not recommended because it gives off an unpleasant bitter smell and produces little heat.

It is best to use firewood from hardwood species with high specific weight. It is desirable that the firewood be dry rather than freshly cut. Remember that when buying wet firewood, you pay more for weight but receive less heat.