Heating With Wood: Why Wood Heat Is Renewable Energy

A leading wood-heat expert explains in epic detail why wood is an essential energy resource.

| March 2, 2010

Heating with wood

EPA-certified woodstoves cut wood smoke by up to 90 percent compared with older, so-called “airtight” stoves.


John Gulland’s involvement with wood burning began in 1974 when he built a woodstove for his own home. Since then he has gained professional experience in virtually every aspect of heating with wood, including product design and manufacture, retailing, standards development, policy and market analysis, laboratory research, professional training and writing. Most recently he helped launch The Woodpile, an advocacy project attached to the popular woodheat.org website. 

By any measure, wood is an important residential energy resource, especially outside large urban areas. More than 10 million U.S. households — a little less than 10 percent of the total — use wood as their main heating fuel or to supplement other heating fuels. More than 25 percent of Canadian households are heating with wood.

A drive through small towns and down country roads in forested regions confirms that fuelwood is a significant energy resource. The long rows of piled firewood standing in yards serve as proof. Every winter, the wood is cut from woodlots, and every spring it’s split and stacked to dry in the summer sun. In the fall it’s moved to the house and stacked again, and in winter it keeps families cozy warm. It’s a seasonal ritual, that has been recurring for generations.

Firewood for home heating is an indigenous, renewable energy resource that helps families stretch their household budgets and strengthen their local economies. And yet, an increasing number of vocal activists are clamouring to have wood burning banned from their communities because of air pollution, and even some environmentalists warn against the increased use of firewood, fearing negative impacts on our forests.

A balanced assessment of firewood for home heating is long overdue. This article explores how burning wood contributes to the prosperity of rural communities, to the health and well-being of their inhabitants, and to the environmental sustainability of our society. It also tackles the problems of wood-smoke pollution and forest resource impacts.

Smoke Emissions

Wood-smoke pollution is the most serious negative result of wood heating, so it’s best to deal with it first.

3/7/2010 2:07:13 PM

Bat, wood heat is green. Like everything else in life there is doing it right and doing it wrong. A properly combusted wood fire will produce no more particulates than oil or NG. Properly combusted you get steam and CO2, unfortunately most, even EPA approved items don't. Even then if you look at the net environmental effects of the energy sources wood comes out way ahead.

3/7/2010 1:50:14 PM

jgulland replied to my concerns by quoting Dr. Anthony Trofymow "I think that for upland temperate forests any methane production from wood decay termites is likely balanced by methane oxidation in the soil by methanotrophic bacteria and thus there is likely zero net release of methane from wood decaying in upland forests." Methanotrophic soil bacteria do not jump into the air and digest the methane there. They do work on the methane produced by the degradation of the stump and roots of a tree and subsoil organics. Speaking from DIRECT experience methane builds up in many slash piles especially during wet seasons, and both the last 2 summers have been very wet in NE Ontario, and when the slash piles are in swampy terrain, somewhat common as they are used to fill and support equipment movement. Mr Trofymow and I are thus speaking of 2 different sinks. Once the methane enters the atmosphere It will have it's negative effect. If he is indicating that the natural migration of air through the soil allows the soil organisms to clean out the methane I would appreciate specific references to journals and articles to support this contention. I am well aware that methanotrophic bacteria exist and how they work, I very much disagree they provide balance in human disturbed systems.

lee einer
3/7/2010 11:02:33 AM

I have a masonry heater in my home, a 1950's adobe. I use about 2 cords of wood, per winter. And I live in the foothills of the Sangre de Christos, where the winter is generally both long and cold. Much of the air pollution associated with woodburning can be alleviated by simply (1) burning dry wood and (2) building fires correctly for a top-down burn. A good, low-smoke fire with a top down burn is accomplished by stacking firewood log cabin fashion, big pieces on the bottom, progressively smaller pieces towards the top, and by igniting the fire at the top of the stack rather than the bottom. With the initial combustion at the top of the fire, smoke from beneath must pass through the area of the flame, and is combusted rather than rising up the flue in the form of creosote. Far more of the pollution can be eliminated by using a stove which burns HOT with ample oxygen, storing the heat in thermal mass. A masonry heater or siberian wood stove is one option, a rocket stove with its flue routed through a mud, stone or adobe banco (bench) is another.

3/5/2010 10:24:30 AM

vacuum1313 wrote: "This calculation failed to take into account that if the wood is simply left in the forest a great deal more methane is produced." Actually, my research revealed that methane is produced by the rotting of trees in only very wet conditions like in a swamp. Dr. Anthony Trofymow of Forestry Canada wrote in response to my question about methane emissions from forests: "I think that for upland temperate forests any methane production from wood decay termites is likely balanced by methane oxidation in the soil by methanotrophic bacteria and thus there is likely zero net release of methane from wood decaying in upland forests." Not too much firewood is taken from swamps, so I stand by the analysis offered in the article John

3/5/2010 9:53:44 AM

Wood heat is not green! Unfortunately, wood heat (also with EPA approved stoves!) produces an intolerable amount of air pollution. Huge amounts of small particulates are produced by any kind of wood heat (compare the amounts at burningissues.org)in comparison to oil and gas heat. These airborne small particulates are asscociated with asthma and other lung diseases. What price are we willing to pay for "cheap" heat? I am very disappointed that Mother Earth is conveying such limited information on the issues associated with wood burning.

3/5/2010 9:07:12 AM

Secondly, woodstoves are inefficient for 3 reasons, bad design, bad fuel and trying to control the rate of burn. have you ever noticed a hot, fast fire has virtually no smoke? This is because it gets enough O2 for complete combustion. This leads to bad design, fast fires are too hot and uncomfortable unless you have a way of storing the heat. High thermal mass stoves that store the heat in masonry, water, stone etc don't get uncomfortable, They store the heat of a short fast fire for hours and release it slowly. Without a lot of technology these are some of the most efficient burners out there and range in cost from many thousands, many tonne masonry heaters, to very little, the rocket mass heater (http://tinyurl.com/yjc5q9l). Lastly is bad fuel. This is exemplified by a conversation at an outdoorsmans club this week. An older member commented on having to pull cups of water out of his trap after every burn. On asking about the fuel it was birch logs delivered in the fall. They were cut but not seasoned hence very high in water! And he wondered why he wasn't getting much heat. Wet fuel burns relatively cold and has lots of incomplete combustion. MEN started life as a DIY learn the skills magazine. It's unfortunate to see how far from these roots the commercialized version has come.

3/5/2010 8:52:24 AM

Just a couple of comments. The first is regarding the CO2 neutrality figures and the inclusion of methane. This calculation failed to take into account that if the wood is simply left in the forest a great deal more methane is produced. If left until they die a lot more methane enters the atmosphere at about 20x more greenhouse effect. Thus combustion vs rot results in a CO2 negative effect (if methane is converted to CO2 equivalents which is what the calculation presented here does). If the timber is harvested and used in construction it goes to landfill at some time and again becomes methane. The calculations used here are a good example of bad math, not considering the entire cycle of a product just one part of it, this is the thinking that eventually led to our throwaway society. Parts 2 and 3 to come, won't fit in the character limit.

3/5/2010 8:03:13 AM

I live in a village where most people heat with wood but nobody is replanting trees and nobody has an efficient stove, I guess, because in the winter I have to drive to the corner store – if I try to walk on the street I choke from all the smoke! I've had to build a gym in my house in order to get some exercise in the winter.

3/3/2010 7:24:33 PM

I've been using my outside boiler since 2003,I have turned my propane on twice in the last seven years for a few minutes to see if it still works.Other than that Ive done all wood.

3/3/2010 6:55:07 AM

I love my insert! This is my first winter heating with wood and it has saved me a ton of $ by not having to buy oil, and my house is a lot warmer with the wood heat than it was with the oil furnace running. Its a lot of work to heat with wood, especially if you scrounge and process your own wood like I do. But even if you dont you still have to load the stove a few times a day, empty out ashes, clean the chimney. It can also be a headache if you're not burning well seasoned wood as the fires dont get as hot as they would with dryer splits. If you're thinking about heating with wood next winter start gathering and splitting your wood NOW. Or if you're ordering from a dealer purchase your cords NOW. Do not wait till next winter or you will have a miserable experience with green or under seasoned wood. Always work a year or 2 ahead.

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