Buy an EPA-certified woodstove

By Jennifer Spero | April 05, 2012

Did you know that heating with sustainably harvested wood in an EPA-certified stove is carbon neutral? Used properly, wood is a renewable fuel that's less polluting — and cheaper — than fossil fuels.

There's nothing like cozying up to a nice warm fire to take the chill off a cold winter day. A woodstove can provide you with an inexpensive, sustainable, and enjoyable form of heat.

But wait a minute — isn't wood a dirty fuel? Isn't natural gas the cleanest burning fuel to use? The oil companies would like you to think so. If you'd like to find out why wood is making a comeback as a way to fight global warming, read on.

Why wood is misunderstood

When many people think of heating with wood, they think of an old Franklin stove and a chimney belching out smoke. Woodstoves have come a long way. If so, why doesn't heating with wood as a renewable fuel get more attention? For one, wood is a low tech fuel compared with other renewables: it doesn't have the glamour of a cutting-edge technology. Secondly, heating with wood is more labor-intensive than heating with other fuels. Fuel wood is, however, the most easily accessible and affordable of all renewable energies.[1] And a woodstove can significantly reduce your carbon footprint if you use wood from a sustainable source and a high-efficiency stove that attains nearly complete combustion.Stoyke, Godo (2007) The Carbon Buster's Home Energy Handbook. Gabriola Island, BC, Canada: New Society Publishers: 113

Wood is carbon neutral

Heating with wood that's harvested in a sustainable manner is considered carbon neutral. This means that although burning wood releases carbon dioxide, growing trees sequesters more carbon dioxide than is released during burning.Wilson, Alex, "Your Best Heating & Cooling Options" Mother Earth News (Summer 2007): 102 Carbon sequestering is a process whereby trees and other plants remove carbon dioxide from the atmosphere and turn it into plant material through photosynthesis. The US Department of Energy (DOE) believes that carbon sequestration is one of the most promising ways to reduce the buildup of greenhouse gases in the atmosphere, and that sequestration will "likely be essential if the world is to stabilize atmospheric concentrations of greenhouse gases at acceptable levels."[2]

What you see is what you get

Heating with wood also makes you personally accountable for your heating fuel emissions. With fossil fuels — including "clean" natural gas — you don't see the pollution firsthand that's caused by the production or transport of the fuel you consume, unless you live in close proximity to an oil refinery or natural gas processing plant. With a woodstove, pollution caused by your burning wood is visible to both you and your neighbors. A clean-burning woodstove operation produces no visible smoke. An improperly functioning system produces visible smoke emissions, making homeowners instantly accountable for their actions.[1]

Find it! EPA-certified woodstoves

About 10 million woodstoves are in use in the US today: 70 to 80 percent of these stoves are older, inefficient, stoves that create significant air pollution. Newer stoves certified by the US Environmental Protection Agency (EPA) produce nearly 70 percent less pollution than older non-certified models.[3] Be sure the stove you choose is on the List of EPA Certified Wood Stoves.

When shopping for a woodstove don't bargain hunt: you'll get what you pay for. Buy from a local woodstove dealer, who can help you choose the right stove, provide a professional installation, supply parts, and teach your how to use your stove. Prices range from $500 for a small cast iron stove to $2,500 for a larger soapstone model.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 111

How to choose a woodstove

To paraphrase Greg Pahl in his book Natural Home Heating, choosing the right woodstove is like choosing a spouse: it's something you'll live with on a daily basis for a long time, and you'll know if you've chosen the right one after you spend a long, cold winter with it.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 104

While that old potbellied stove in the antique shop or that free JÌütul on craigslist may look appealing, neither may be a bargain in the long run. For efficient — and eco-friendly — wood heating, choose a woodstove that's been manufactured since 1988 and is EPA-certified. In this case, recycled isn't necessarily a good thing: most woodstoves manufactured before 1985 have only a 20 to 60 percent efficiency rating: 40 to 80 percent of the wood's available energy literally goes up in smoke, wasting heat and polluting the air. Today's EPA-certified stoves achieve at least a 70 percent reduction in particulate emissions and deliver efficiency ratings up to 80 percent, competitive with many boilers and furnaces.Trethewey, Richard, (1994) This Old House Heating, Ventilation, and Air Conditioning. Boston: Little, Brown, & Company: 149-151

Catalytic or non-catalytic?

The most common types of woodstoves fall into two categories: catalytic and non-catalytic. A catalyst is an agent that speeds up a chemical reaction or allows it to occur under different conditions. With catalytic woodstoves, the catalyst aids the chemical reaction between the oxygen and the organic materials when they're heated. Temperatures inside a woodstove are generally around 400°F to 900°F. While this is a high enough to heat most of the wood, it's not high enough to ignite all the hydrocarbons emitted as the wood burns. These hydrocarbons contain much of the wood's energy.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 103[4]

Catalytic stoves contain a ceramic, honeycomb-like combuster coated with a metal such as platinum or palladium. The metals on the catalytic converter act as a catalyst to ignite these gases at lower temperatures (350°F to 600°F).Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 103 This catalytic feature has two advantages. First, it increases the stove's efficiency 10 to 25 percent by burning hydrocarbons that would otherwise go up the chimney. Secondly, it burns the wood more completely, so there's fewer emissions — meaning less air pollution and less creosote building up in your chimney. The disadvantages are that catalytic converters have to be replaced every three to six years at a cost of $100 to $200, they take longer to get a fire going, and the stoves are more finicky to operate. If the combuster isn't functioning properly or is damaged, the stove will emit much higher levels of pollutants than a non-catalytic stove.

About 80 percent of woodstoves on the market are non-catalytic. Catalytic and non-catalytic stoves use different means to meet EPA particulate levels. Non-catalytic stoves are comprised of a firebox, air controls, and baffles which recirculate the smoke for better combustion.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 103 This "secondary combustion" is what makes new EPA-certified non-catalytic stoves burn much more cleanly and efficiently than older non-certified models.[5] Non-catalytic stoves have smaller fireboxes than catalytic stoves, for hotter fires, and are lined with insulation or firebricks to promote higher combustion temperatures.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 103 The advantages of non-catalytic stoves are that they require less maintenance, are easier to get a fire going in, and are easier to operate.[6]

Which is best?

Which is better: a "cat" or a "noncat"? This debate has been going on for nearly 20 years, with strong opinions on both sides. The market seems to be favoring noncats, and some manufacturers have moved in that direction.[7]

Catalytic converters were originally added to woodstoves in the 1980s as woodstove manufacturers sought an add-on to make their existing stove models meet new woodstove emission regulations in several states.[6] Now, newer non-catalytic stoves have been designed specifically to incorporate cleaner-burning technology. Some stove manufacturers feel that catalytic stoves are too difficult, costly, and time consuming for the average homeowner to operate, and have chosen to go with non-catalytic designs.

If you have a non-catalytic stove and decide you want to convert to catalytic, however, most modern non-catalytic woodstoves can be retrofitted with a catalytic damper, which is sold as a kit and usually installed in the flue collar. To monitor the stove's temperature after adding the catalytic damper, you should also install a heat sensor on the stove or the stove pipe. These kits are available from woodstove retailers, but may not be suitable for all stove models.[8]

The bottom line: you'll have to weigh the pros and cons and decide which type is right for you. Whether you choose a cat or a noncat, if your stove is EPA-certified and you use it correctly, you'll have a clean-burning stove.

Steel, cast iron, or soapstone?

While there are myriad of choices when it comes to woodstoves and wood-burning appliances, one primary decision is whether you want a stove made of steel, cast iron, or soapstone. What are the pros and cons of each?

A steel stove heats up quickly and supplies lots of intense rapid heat, but it cools down rapidly once the fire's out. Steel stoves are good for a room with cathedral ceilings, large areas, or basements, and will hold their heat for 10 to 12 hours.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 103 Soapstone is just the opposite: it heats up more slowly as the heat has to penetrate the stone, but it stays hot for hours after the fire's out. Soapstone is a good choice if you intend to use the stove as your primary heat source. Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 103 Cast iron stoves fall somewhere in between: They heat up quicker than soapstone and retain heat better than steel, so they're a good compromise.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 103

Finding the right fit

The most important factor in choosing a woodstove is getting the correct size. A stove that's too big will either make your house feel like an oven or force you to operate it at too low a temperature, which creates creosote buildup in your chimney and more air pollution. Having a stove that's too small is actually better than having a one that's too big. You also can't always go by the product literature when choosing a stove. The layout of your house, the size of your rooms, how airtight your house is, and how cold your winters are also affect which size stove you should get. HearthNet has an online calculator to help you size your stove, but it's best to get advice from your local woodstove dealer.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 104-105

Buying an EPA-certified woodstove helps you go green because…

Most older woodstoves (manufactured before 1985) burn inefficiently with a large percentage of the wood's available energy going up in smoke. This results in heat waste and air pollution.Trethewey, Richard, (1994) This Old House Heating, Ventilation, and Air Conditioning. Boston: Little, Brown, & Company: 149-151
EPA-certified stoves significantly reduce particulate emissions and deliver high efficiency ratings, competitive with many boilers and furnaces.Trethewey, Richard, (1994) This Old House Heating, Ventilation, and Air Conditioning. Boston: Little, Brown, & Company: 149-151
Heating with wood that's harvested in a sustainable manner is considered carbon-neutral. Although burning wood releases carbon dioxide, growing trees sequesters more CO₂ than is released during burning.Wilson, Alex, "Your Best Heating & Cooling Options" Mother Earth News (Summer 2007): 102
A woodstove can significantly reduce your carbon footprint if you use wood from a sustainable source and a high-efficiency stove that attains nearly complete combustion.Stoyke, Godo (2007) The Carbon Buster's Home Energy Handbook. Gabriola Island, BC, Canada: New Society Publishers: 113

Heating your home with fossil fuels not only results in a high cost to you, it also comes at a high cost to the environment. The Union of Concerned Scientists analyzed the ecological impact of the most common consumer actions and products and ranked "home heating, air conditioning, and water heating" fourth in its list of the "seven most harmful human activities" the environment.[9]

Related health issues

If a woodstove is installed and used correctly, it doesn't release smoke into your house. Also, if a fire is burning properly, you should see little or no smoke coming from your chimney. If you see lots of smoke, that's air pollution, and it can affect your health and that of your neighbors. Wood smoke is made up of gases and fine particles that can cause burning eyes, a runny nose, or bronchitis. Fine particles in smoke can exacerbate heart and respiratory diseases, such as asthma.[10]

To prevent illness, only burn dry, seasoned wood. Never burn household garbage including cardboard, plastics, magazines, colored newsprint, boxes, gift wrap, or food wrappers; coated, painted, or pressure-treated wood; ocean driftwood, plywood, particle board, or any wood with glue on or in it; or wet, rotted, diseased, or moldy wood.[10]

If you are sensitive to mold, check firewood for signs of mold, and don't store excess amounts of wood inside to reduce the chance of allergy-causing mold spores circulating inside your home.[10]

Controversies

Air pollution

Woodstoves are not an ideal heating source in all situations, particularly in heavily populated areas, valleys, and locations with certain weather conditions. In Washington, for example, wood smoke is the state's third-leading cause of air pollution, making up about 11 percent of yearly air pollution. Nearly half of all Washington households use woodstoves, fireplaces, or other wood-burning appliances. Weather conditions that cause smoke to be trapped at ground level add to the problem. The state imposes local "burn bans" at times when smoke reaches unsafe levels.[11] The state also assesses a flat fee on the sale of every wood burning device to fund the educational programs on air quality impacts and the benefits of clean burning wood stoves.[11]

Deforestation

Another controversy arises due to media reports that heating with wood will deplete our forests. A joint report by the DOE and US Department of Agriculture (USDA) published in April 2005 found that US land resources could produce a sustainable supply of biomass fuel that could replace 30 percent or more of the country's present petroleum consumption.[12]

The total forestland in the United States is about 749 million acres — one-third of the nation's total land. Two-thirds of this forestland (504 million acres) is classified as timberland. Of this timberland, approximately 29 percent is publicly owned, 13 percent is owned by the forest industry, and the remaining 58 percent is privately owned. Today, about 75 percent of biomass consumption in the US comes from forestlands.[12]

The amount of forest-derived biomass that can be sustainably produced in the US is about 368 million tons per year — more than 2.5 times the current consumption. Currently, about 41 million tons of forest residue produced by logging and land clearing operations goes uncollected — wasted — as well as 96 million tons per year from other sources.[12]

As the Canadian Renewable Energy Network (CanREN) points out, people not involved in forest or woodlot management often find it difficult to comprehend the rate at which trees grow and die. CanREN notes, "The turnover in the forest is truly impressive, and even the most casually managed sustainable yield approach will allow significant harvesting without depleting total forest stocks."[13]

Sustainable wood

Lastly, many fear that extensive harvesting of cordwood will lead to the ecological damage caused by clearcutting, a practice whereby logging companies remove all trees from a tract of land. Concerns arise that cordwood dealers and individuals cutting their own firewood may not be practicing sustainable woodlot management. Only a few states have any certification programs, one example being Vermont Family Forests (VFF). Clearcutting as practiced by Big Lumber is decidedly eco-unfriendly. Firewood should always be purchased locally, in which case you can check out the dealer's logging operation for yourself. Clearcutting is seldom practiced by small woodlot owners, as it wouldn't make economic sense. Also, many woodburners harvest standing deadwood on their own property or get free windfall wood from neighbors, both sustainable practices.

Tax breaks and subsidies

The EPA, in coordination with other industry groups, sponsors a Wood Stove Changeout Campaign. With this campaign, consumers receive financial incentives in the form of rebates to replace older woodstoves with either EPA certified wood stoves, pellet stoves, or non-wood burning equipment (such as vented gas stoves). While these programs are currently only available in certain areas, more are in the works.[3]

The federal government, and many states, offer heating assistance for low-income families. The subsidies may be applied to traditional fuels such as oil and gas, as well as to renewable fuel alternatives, including wood, which is a popular low-cost heating fuel in many rural areas. Most of these programs apply not only to homeowners, but also to renters whose rent does not include heat.[14]

Glossary

baffle: A baffle is anything that slows or changes the direction of the gases in the stove. Most baffles are steel, cast-iron, or refractory brick plates installed at the top of the firebox. Smoke and gases must move around the baffle before exiting. This increases the amount of time the gases remain in the stove, allowing time for more complete combustion.[15]
carbon monoxide: A colorless, odorless, lethal gas that is the product of incomplete combustion of carbon.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 264
carbon neutral: A product or process is considered carbon neutral if over its life cycle, it doesn't add more carbon dioxide to the atmosphere. For example, a tree consumes carbon dioxide while it grows, then when it's cut and used as home heating fuel, it releases carbon dioxide back into the atmosphere.[16]
carbon sequestering: a process whereby trees and other plants remove carbon dioxide from the atmosphere and turn it into plant material via photosynthesis.
catalyst: An agent that speeds up a chemical reaction or allows it to occur under different conditions.[4]
catalytic combuster: A device using a catalyst to promote the ignition of air/exhaust gas mixtures at a temperature that is lower than would usually be required.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 264
catalytic woodstove: A woodstove that uses a catalytic combustor to help ignite combustion gases.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 264
clearcutting: A method of logging that can destroy an area's ecological integrity by the felling and removal of all trees from a given tract of forest.[17]
creosote: A deposit of condensed wood smoke, including vapors, tar, and soot, that condenses on stovepipes and chimney flues as a result of a smoldering fire. Creosote buildup is the main cause of chimney fires.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 265
damper: A movable valve or plate in a heating device that restricts or shuts off the draft.Pahl, Greg,(2003) Natural Home Heating: The Complete Guide to Renewable Energy Options. White River Junction, VT: Chelsea Green Publishing Company: 265
firebox: This is where you build the fire. Some are lined with masonry firebricks or refractory cement, while others are lined with steel or cast-iron panels.[15]
flue collar: The opening in the top, rear, or side of the stove (usually round or oval), to which the stovepipe is connected, and through which exhaust is vented from the stove.[15]