The smell of woodsmoke holds a special appeal for
romantics, outdoor enthusiasts and golden retrievers, but
research shows that its smoke poses serious health risks
Why should you care about does burning wood properly matter? Because Change behaviour, watch for the Air Quality Index
Particulate Matters – What is all the fuss about PM2.5?
Cancer rates – Harrison – Explain to people about the cancer rates
The key to being a successful burner
The three necessary ingredients for efficient and environmentally friendly wood heating are: 1) well-seasoned firewood, 2) a certified woodstove that is properly installed, and 3) good fire-burning techniques.
This article is the first in a 3-part series on how to Burn it Smart, brought to you by the Quesnel Air Quality Roundtable. This article (Part 1) will review the importance of burning properly seasoned firewood. Part 2 will review new woodstove technology and instillation tips, and finally, Part 3 will cover good-fire burning techniques.
Part 1 – Well Seasoned Wood
Seeing firewood stacked and ready to burn represents warmth and security throughout the long cold Cariboo winter. Knowing how to dry (season) firewood correctly is essential as wood dries slowly. Firewood should be cut in the spring and piled outside so that the wind and sun can season the wood properly. If you cut and stack your firewood in the woodshed before it is seasoned, you risk it rotting and not drying out properly.
Well seasoned firewood should have a moisture content between 15 and 20 percent. It takes 6 months or more for newly processed wood to dry to that level because the native moisture content of trees ranges from 30 to 50 percent. The efficiency losses resulting from burning wet wood can be as much as 30 percent.
Drying firewood properly prevents a lot of wasted wood and results in wood that burns much more cleanly, producing less smoke and producing more heat. Seasoning of firewood begins when the seal is broken by splitting the wood. So if you are purchasing firewood and want to know if it is seasoned, ask “When was it split?” The answer for well seasoned wood should be at least 6 months ago.
How can you tell if wood is properly seasoned? For a high tech option, you can purchase a hand-held moisture reader. The Nature Education Resource Centre here in Quesnel has one of these units if you would like to see how it works. For more low tech options, you can use the indicators listed below. But use as many indicators as possible to judge the dryness of firewood.
Indicators to test the dryness of wood include:
– Two dry pieces banged together will sound hollow. If wet, the sound will be solid and dull.
– Wood tends to darken from white or cream colour to grey or yellow as it dries.
– Look for checks or cracks in the end grain. Be sure to combine this indicator with others as some wet wood has checks and some dry wood has no checks.
– Dry wood weights much less than wet wood.
– Split a piece of wood. If the exposed surface feels wet, the wood is too wet to burn.
– When in doubt, burn some. Firewood that isn’t dry is slow to ignite. It smokes and smolders in the fire, causing both indoor and outdoor air pollution and leaving creosote deposits in the chimney.
It takes a lot of energy to heat and vaporize the water in wet wood. As much as 15 percent of the energy content of wet wood can be consumed turning water into steam. Wet wood is so hard to burn that part of its potential heat energy is wasted as smoke, and it creates a sluggish fire that will smolder unless the air control is left wide open. But an open air control will cause much of the heat produced to be rinsed out of the firebox and right up the chimney by such a high airflow rate. In contrast, properly seasoned wood lights easily, burns cleanly and efficiently and will continue to flame even if the air control is turned down for an extended time.
If you commit to using properly seasoned firewood, wood heat can be a clean and renewable energy that’s more accessible than solar or wind.