Ask TreeHugger: Wood vs. Pellet Stoves
by Helen Suh MacIntosh, Cambridge, MA, USA 
on 04.10.07
Question: We recently purchased a condo in the Boston area (Somerville, to be specific), and after a winter heated by the existing (gas-fired) forced air heating system we're thinking about looking at alternatives to augment our heating system and hopefully simultaneously reduce costs. [More after the jump.]
The heater we have is fairly new and should last for longer than we're likely to stay here, so we're not too keen to just replace it outright. Instead, we were thinking about the possibility of something like a wood stove which would not only provide heat, but would add a little character to our home. My understanding has been that modern wood, but especially pellet and corn, burning stoves have pretty low emissions and low cost of ownership and use. Obviously people have been using them to heat their homes for about as long as we've had homes, but I was hoping to learn more about the modern variants.
How do wood, pellet, and corn burning stoves compare to each other and to other heating methods in terms of indoor air quality and emissions?
Response: You are right that modern wood, pellet and corn burning stoves, have low pollutant emissions. They are each a substantial improvement over the traditional wood burning fireplaces and stoves, which emit hundreds of different types pollutants into the air and are known to harm indoor and outdoor air quality. While also burning wood, EPA-certified wood burning appliances include a device that allows for more efficient – and less polluting – wood burning. As a result, these EPA-certified wood burning appliances emit less pollution and are safer than their more traditional wood-burning counterparts. Pellet stoves, which generally use wood and/or corn based substrates, are more complicated but also pollute less than the EPA-certified wood burning stoves and in fact, any other heating appliance that burns solid fuels. The U.S. Environmental Protection Agency recommends that traditional fireplaces be replaced with non-wood burning stoves (for example, vented gas stoves), pellet stoves, or EPA certified modern wood stoves.
What this means for you is that given proper venting, installation and maintenance, the EPA-certified wood, wood pellet, and corn pellet stoves would each probably have little effect on your indoor air quality. The wood pellet and corn pellet stoves, however, would likely have the least impact on outdoor air quality, as they emit much less pollution than the EPA-certified wood burning stoves. This is evident when comparing the smoke coming out of the three stoves, with the wood pellet and corn pellet stoves being so efficient in the burning process that the smoke emitted from their vents is clear as compared to grey or black. Their efficient burning has an added benefit to the home owner, allowing wood pellet and corn pellet stoves to be vented outdoors through a pipe in an outside wall instead of through a chimney. As a result, wood pellet and corn pellet stoves can probably be installed in almost any room in your condo.
Of course, there are other things to consider in choosing between the three types of stoves, including their ease of use, maintenance, fuel cost and supply, heat production, and other indirect costs to the environment. In these regards, the three stoves each have different advantages and disadvantages. For example, pellet stoves require electricity to work, which depending on your local power source may result in extra costs and added pollution above a traditional EPA-certified wood stove. Also, local (and cheap) sources of wood pellets or corn pellets are not available in every location. My guess is that in Massachusetts, it may be more difficult for you to find a reliable and inexpensive source of corn pellets, although with their growing popularity maybe this will become easier over time.
If you want more detailed information on any of the three stove types, I would suggest two different places to look, including www.eere.energy.gov and www.epa.gov/woodstoves/. Also, we have several earlier TreeHugger posts on pellet stoves that may be interesting to see what people are saying about them (Corn Brning Stoves, Wood Pellet Stoves and Pellet Stoves again.)
Previous Ask Treehugger columns can be found here.
Helen Suh MacIntosh is a professor in environmental health at Harvard University and studies how pollution behaves in the environment and how it affects people's health. Please keep in mind that her answers are just her interpretation of available information and should not be taken as the only viewpoint or solution to a problem. Use this column at your own risk. Having said this, please feel free to post any of your environmental health questions to Helen@TreeHugger.com (please use a descriptive email subject line and mention if you want to remain anonymous or not).
See also: Thinking of Buying a Pellet Stove? We Can Help!
Update: Check out our guide to Buy Green: Pellet Stoves over on our sister site, Planet Green. You know they're a great green way to heat -- learn where to get one and take action today!
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If you want clean burn and efficiency I'd suspect that a wood boiler (with heat storage tanks) might very well be the way to go.
Remember that those big scary orange and yellow circles are carbon neutral.
Using wood (EPA certified of course) is using, quite literally, one of the few fuels that can be gotten from your own backyard. Or at least a very local source, within 10-15 miles. Your corn or pellets are probably being trucked in from a ways away if you don't live in a rural area.
carbon neutral is important, but PM emissions are also important. Some residential areas are more poluted than urben centers because of all the wood stoves. Bad for lungs, especially of children.
I strongly encourage people who want to burn wood to get a high efficiency stove and learn how to operate it optimally.
Personally, I'm in favour of wood as a fuel ... in a masonry cooker/heater. Especially in a passive solar design.
Why no mention of masonry stoves?
The efficiency and particulate matter of masonry stoves are far superior due to the very 'fast, hot' burn providing for highly complete combustion. Admittedly, it's best as a 'designed in' approach for new construction, but there are retrofit models.
"Fine particle pollution is one of the nation’s most pervasive air pollutants and its most deadly, causing tens of thousands of premature deaths every year. This report examines levels of fine particle pollution in cities and towns nationwide in 2004 and finds that fine particles continue to pose a grave health threat to Americans."
"Fine particle, or “soot,” pollution can cause serious respiratory and cardiovascular problems, including asthma attacks, heart attacks, strokes, lung cancer, and premature death. Moreover, recent scientific studies show that such adverse effects occur at levels below the current national health-based air quality standards..."
I am somewhat confused by this posting and the comments attached to it. Does that comparative graphic take into consideration the pollution caused by oil in the drilling, refining and delivering process? I understand that a woodstove causes more direct pollution than an oil furnace itself. But what about the cost when you examine the bigger picture? I would appreciate any postings that would clear this up for me.
Elizabeth- excellent point, and while I'm guessing, I know from personal experience that this kind of analysis, done by a regional agency, is VERY unlikely to take anything into account except the very local particle problem. Cost of transport from the other side of the world? Not included. Etc.
Hi guys,
I would like to recommend this website:
E.nergi.es - wood pellets biomasses and stoves company directory and product reviews.
It's a community-driven website where anybody can add a company, info about a product and, most important, review companies and products for the benefit of other people.
No registration needed.
Regards
I am looking to purchase a pellet boiler to replace my 8 year old oil boiler, this has an attached water tank it heats too. But I want an indoor unit with a hopper. Any recommendations to heat a 3500 sq. ft house? New Jersey area
Okay so I've been seriously considering a wood pellet stove to help offset my oil bill but I really don't want to jump in a buy just any old pellet stove, especially a loud and clanky one. I do want an EPA approved pellet stove mainly because of my kid and neighbors but am having a hard time finding anything out there that seems to be of a higher quality that is readily available.
I have been looking at the Ecoteck pellet stoves for some time now, because they seem to pass all sorts of European standards, and they are finally being imported into America, but I can't seem to find anyone that has one.
Does anyone here know anything about them? Or know of anyone that has one?
@Energies: Thanks a lot for that link I'm going to check it out right now.
Pellet stoves are an excellent means for supplementing your heating. When looking for a pellet stove, insure that the pellet stove you are looking at is a multi-fuel stove. Often times, pellet stove owners run out of wood pellets and can not find them any where during the cold winter months...a pellet stove that can burn multiple types of fuel is certainly a wise choice.
I was thinking of buying a pellet stove insert to replace a cheap non-efficient gas fireplace, installed buy homebuilder more for show than function.
Is this possible?
Any advise?