As winter oil and gas prices cause wallets everywhere to burst into flame, more and more Americans are turning to woodstoves to warm their hearts and a whole lot more. Using a less expensive homegrown fuel source, woodstoves have become a hot commodity. But fires mean smoke and where there’s smoke, there’s pollution. Our guide to burning wood, not lungs, will help you and your neighbors breathe a little easier this heating season.
There’s a lot to like about woodstoves. Here in Vermont, many of our friends heat their homes entirely with wood, and it’s easy to see why. When properly harvested, wood is a sustainable fuel that literally grows on trees. The heat it produces is bone warmingly deep. And the glow from a woodstove with a glass door is a comfort all its own on a cold winter’s night.
Of course, woodstoves are not without their disadvantages. They require fairly constantly tending. They can be more than a little dirty, and wood is a heavy bulky fuel that requires a lot of space to store and a lot of muscle to cut, stack, and carry.
There’s also the pollution that woodstoves create, and that’s often no small matter. Unlike gas and oil furnaces which burn with varying degrees of relatively clean efficiency, woodstoves can produce often prodigious amounts of particulates, a class of air pollutant that comes in the form of tiny solid particles of toxic soot and other unburned materials, all of which are quite adept at harming both the cardiovascular and pulmonary systems.
In fact, the EPA says that woodstoves are responsible for 5% of all the particulate pollution in the United States. Fortunately, the pollution news where woodstoves are concerned isn’t all negative. At least one study has found that wood creates fewer emissions linked to acid rain and global warming than any other home heating fuel. This means that when particulate emissions are controlled, wood can be a relatively clean source of warmth.
That’s especially true where newer stoves are concerned. Woodstoves sold today benefit from tough emission regulations that took effect in 1992. These rules mandated cleaner burning designs that include catalytic converters and/or second- and third-stage combustion chambers. Such technologies can reduce by two-thirds the amount of pollution stoves create.
That’s a good thing, but these newer stoves represent only about 25% of all those in operation today. Cast iron woodstoves, after all, last a long time. The remaining 75% of the country’s stoves were made prior to 1992, and the dirtiest of these can produce the air pollution equivalent of seven diesel buses!
Whether you heat with a new stove or an older model, however, there is plenty you can do to reduce its environmental impact. Here are some tips that will help you heat your house without undue harm:
• If you use a stove built prior to 1992, consider a new model. New stoves have cleaner burning designs and incorporate technologies that send more heat into your home instead of up the chimney, which makes more efficient use of your wood pile. Another option is a pellet stove, which burns manufactured pellets of compressed wood scraps. Pellet stoves are cleaner still and use a convenient, electrically powered feeder system to automatically provide the stove with a steady supply of fuel. That means no hauling wood or tending fires. This reliance on electricity, however, is also a pellet stove’s Achilles’ heel. In a power outage, a pellet stove is rendered inoperable, a fact that those seeking self-sufficiency in emergencies and other situations should consider.
• Use only clean, black and white newspaper to start your fire.
• Burn only seasoned wood in your stove. Unseasoned or green wood will provide less heat and create more pollution when burned. Seasoned wood is wood that’s been cut, stacked, and left to dry for at least six months. Seasoned wood will be somewhat darker in color than fresh-cut wood and will have cracked ends in which small splits in the wood radiate out from the center of the log like spokes on a bike wheel.
• Burn a hot fire by making sure it gets plenty of air. “Cooler” fires produce more smoke because the heat they’re creating is insufficient to completely burn the smoke being produced.
• Check your chimney to verify your stove emissions. You should see a thin white-to-clear stream of smoke or vapor coming out. A darker stream indicates the need for a hotter fire.
• Buy a stovepipe thermometer and monitor the temperature of rising gases. Though target temperatures vary from situation to situation, a stovepipe temperature of between 300_and 400_ usually indicates a fire hot enough to burn off particulates and most gases.
• Well-burning wood produces flames until only charcoal is left. If you see glowing wood but no flames, your logs are smoldering rather than burning.
• Similarly, stoves that are more completely combusting their emissions produce bright orange/yellow flames. Dark orange or reddish flames indicate the need for more heat.
• To create a hotter fire, add more air by opening up the air intake further. Burn smaller pieces of wood 4-6 inches wide instead of large single pieces of wood. Stack these smaller wood pieces in a criss-cross type pattern that provides plenty of space in and around them for air to flow.
• When you start a fire, start it hot. Open up the damper to heat the stovepipe and chimney. Once started, this heating will self-perpetuate and draw a steady flow of oxygen into your stove for cleaner burning.
• Don’t burn so-called manufactured “designer” logs like those found in supermarkets. These are made from petroleum waxes and other unhealthy ingredients and provide much less heat than old-fashioned wood.
• And don’t forget to insulate your house! Sealing windows, doors, and cracks, etc. with weather-stripping and other forms of insulation will mean you’ll need to burn less wood to stay warm.
For more information about clean woodstove operation, including lists of EPA-recommended high-efficiency models, visit http://www.epa.gov/woodstoves. Additional advice and information can also be found at http://woodheat.org/.
This article originally appeared in "The Non-Toxic Times," an e-newsletter
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