EPA says your wood stove should be more efficient

Photo: lamcoopphis, Creative Commons, some rights reserved

Photo: lamcoopphis, Creative Commons, some rights reserved

Recently, the Environmental Protection Agency released proposals for new, federal restrictions on wood stoves. The rules would only affect residential heaters manufactured after 2015.

The EPA estimates (somewhat boldly) that its new restrictions "would reduce emissions of fine particle pollution from new manufactured woodstoves, pellet stoves, hydronic heaters and forced air furnaces by an estimated 4,825 tons a year – an 80 percent reduction over estimated emissions without the rule."

So what exactly is "the rule"? How will the EPA go about reducing emissions so drastically? Their main focus will be on wood stove design. The EPA says it will work directly with manufacturers to make sure their future boilers and burners run cleaner – for example, by equipping them with devices called catalytic combustors, which directly filter out pollutants.

The EPA says the current rules – which haven't been changed in 25 years – are not up to date with technological advancements that allow wood to burn more thoroughly. Some of the best examples of up-to-date, high-efficiency stoves were on display at the Wood Stove Decathlon, a contest held late last year in Washington, D.C. Some of the stove models could harness 90 percent of the energy contained in logs. These burned not only the logs themselves, but also the gases they release. Typical wood stoves can deliver only 40 to 50 percent of a piece of wood’s energy potential.

If the EPA's proposal is approved, it would be the first change to the rules on wood-fueled residential heating since 1988. This is the result of a lawsuit filed in October by New York Attorney General Eric Schneiderman, along with a coalition of six other states.

Wood-fueled heat is a huge part of the North Country culture and lifestyle. According to the latest census data, 14% of houses in St. Lawrence County are heated with wood. (That's a lot – only 2% of buildings statewide are heated in this way.)

But wood smoke contains pollutants that add to humans’ carbon footprint and harm our lungs. Speaking to the New York Times, Clarkson University professor Philip Hopke said, “If you can see it, if you can smell it, that’s energy that isn’t heating your house.”  Instead, it’s putting carbon monoxide and fine particles in the air. When you inhale these fine particles – also called PM2.5 – they make their way into the bloodstream, and can cause all kinds of health problems. Young children, older adults, and people with previous lung conditions like asthma are at a higher risk.

Especially notorious for high levels of pollutants are the outdoor, hydronic heaters (or “boilers”). They tend not to burn logs as thoroughly.

The next step for the EPA’s proposal is a public hearing in Boston in late February. In the meantime, want to be more efficient and eco-friendly with your current woodstove or boiler? Check out some tips at the EPA’s Burn Wise program.

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5 Comments

  1. While an old inefficient wood stove does enlarge one's carbon footprint, a modern very efficient stove does not. In fact any older gas or oil furnace could easily have a lower efficiency rating than the newest wood stoves, and THAT will increase your carbon footprint for sure.
    A good, clean-burning, efficient wood-stove…burning clean, dry, well-seasoned wood is better for our environment than any fossil fuel burner…no matter how efficient.

  2. I agree with Michael that having seasoned wood makes a huge difference in how much heat and how much pollution is created per log.

    I wonder about the designs to incorporate catalytic converters into stoves. This idea was tried in the 80s with poor results because woodsmoke, especially from poorly seasoned wood, contains a lot particulate that quickly clogs converters. Presumably the new designs take that into account.

    The most efficient stoves currently on the market are welded, not cast, and lined with firebrick. A '"smoke shelf" of hot firebrick helps to burn the gases contained in the smoke. We love our woodstove, and are kicking ourselves that our wood isn't quite dry enough this year, due to the very wet spring we had.

  3. Also, a HOT fire at least once a day for 30 minutes or so is really important for reducing creosote buildup.

  4. Dry firewood eliminates creosote as well. At over $4.1 a gallon I need the wood alternative. Having oil helps when I cannot be home and with one firebox the whole furnace takes less space than having two furnaces or having a supplementary stove which I have no place to set.

  5. I agree with Michael and Ellen about using ONLY seasoned wood – this is so critical that I have several different stacks of wood drying at all times so I never get caught having to use unseasoned wood like I did 1 year. Educating consumers about the importance of using seasoned wood is important. Also,Ellen hit on a very important point regarding the designs the EPA will require to incorporate the catalytic converters into the new stoves. If we can educate the consumer,not only about the benefits of the new requirements but also for those that will not be upgrading to a new model in the next 30 years how to make the most efficient use of their current "old" woodburning stove, then we'll start making progress.