Ask TreeHugger: Wood vs. Pellet Stoves


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!

Tags: Pollution