There was a tendency during the development of the first round of EPA’s wood stove emissions regulations in the 1980s to rely exclusively on science and technology to reduce emissions from wood heaters. This made perfect sense at the time because most wood stoves were crude boxes with virtually no emission control technologies.
Unfortunately, a repeat of this approach appears to be reflected in much of the recent commentary surrounding the EPA New Source Performance Standard (NSPS) review process. Unfortunate because this repeat of the reliance entirely on technology can result in appliances that burn cleanly under laboratory conditions through increased technological complexity but which do not meet user needs. This could produce disappointing emission reduction results in actual use.
Wood stove manufacturers made big improvements twenty years ago to meet the first round of EPA’s emissions regulation and they have continued to refine their technologies ever since. The incremental improvements over that period were mostly prompted by market forces as stove makers competed for market share.
It hardly needs mentioning that wood stoves don't work without human intervention. Unlike other heating systems, the proper function of wood burning appliances is in the hands of the user. The knowledge level and attitude of the user will be reflected in the amount of smoke their wood heating activities produce. We know there are users who take great pride in the fact that their neighbors are scarcely aware that they heat with wood because smoke is almost never visible at their chimney top.
We also know that people who don’t care about the impacts of their actions on neighbours and are content to remain ignorant of good wood burning practice will make a lot of smoke, regardless of the emissions rating of the appliance they choose.
But there must be a great majority in the middle who are simply not aware of the mistakes they continue to make in the use of their wood burning appliance.
Considering the influence of user input to the amount of smoke a wood burning appliance emits, it is remarkable how little effort has been devoted to supporting the public in using wood burning appliances effectively. While the industry and various government agencies have made some effort at public education, virtually no resources have been applied to researching how people learn, what techniques could produce lower emissions, and whether the messages that have been tried are effective.
We wouldn’t rely on a doctor to provide financial advice, or on a philosopher to fix our car, so why do we rely on technologists to develop public information on wood heating? Appliance designers, test lab managers, government technologists and others have tended to downplay the potential benefits of high-quality public information on smoke emissions. This is not surprising because the fields of psychology, sociology and adult education are entirely outside their areas of expertise.
In Strategies for Reducing Residential Wood Smoke published October 29, 2009, the Outreach and Information Division of EPA wrote: “Engaging the public and giving them the tools to make the right decisions about what they burn and how they burn is the first step in an overall wood smoke plan. With proper burning techniques and well-seasoned wood, emissions (even in older stoves) can be significantly reduced.”
That statement implies that some people within EPA understand the importance of public information in smoke emission reduction, and we agree with them. Our concern is that the real challenges of reaching people with messages they will act upon by changing their wood heating behaviors have been consistently under-estimated by just about everyone.
There are two dimensions to the challenge of changing wood heating behavior. The first dimension is proof of effectiveness. The actual techniques that are thought to be associated with lower emissions have been based largely on hunches, assumptions and opinion because almost no effort has been made to quantify their relative effects. The benefits of using strategies such as ‘burn dry wood’, ‘do not smoulder’, ‘don’t overload the stove’ and so on have not been quantified, and as a result, we can’t say that a particular technique can reduce smoke emissions by ‘x’ or boost efficiency by ‘y’. The operating instructions that dealers, manufacturers and governments have suggested for thirty years hardly rise above the level of hearsay.
Research projects designed to quantify the effects of various operating strategies would be a good start. These could consider issues such as wood moisture, piece size, load size and configuration, kindling technique and so on. The objective would be the creation of authoritative statements of relative effectiveness that are backed up by scientific evidence.
The second dimension of the challenge of changing behavior is to design the methods and materials for communicating to users. This process is more than just choosing between a booklet or video, but involves crafting the messages and placing them in a framework that people can learn from easily. It is analogous to the development of product marketing strategies and materials that make the purchase decision seem easy and obvious.
Helping the public to reduce wood smoke by improving their wood burning technique is virtually unexplored territory. The wide distribution of high quality public information would give responsible wood burners the tools they need to improve their wood burning practice, regardless of the technology they use. For those who refuse to burn wood properly, even after being provided with authoritative information on good operation, local by-laws on smoke opacity limits could be effective.
Unfortunately, the human factor in wood heating is not being discussed as part of an emission reduction strategy. Instead, what we hear about in the industry rumor network is of sub-2 gram per hour stoves using a patent-pending technology that will be unvailed with a flourish by their makers. We also hear about a return to catalytic combustion and greater technical and operational complexity.
Maybe the engineers are right and such stoves will function well, be durable and economical and please their users. But with companies under extreme pressure to develop stoves that produce ultra-low emissions in laboratory conditions, there is a risk that their performance will not translate into good real-world performance.
Why so sceptical? For one thing, the track record of highly complex wood stoves is not good. By far the most successful wood stoves, both in terms of low emissions and user satisfaction, are manually-controlled and straightforward in configuration. What makes them special is good design produced by long hours in the laboratory. They work well in real homes because they are flexible enough to handle firewood of different densities and piece sizes, and their controls easily understood, even by non-technical users.
The last twenty years of North American wood heating history is littered with a number of complicated stoves that savvy dealers wouldn’t carry because, while they looked good on paper, didn’t function well in people’s homes.
We hope we’re wrong, but past experience does not inspire confidence in the success of highly complex wood stoves. Our experience suggests that the best control system for a wood heater is an informed human being. More effort should be made to inform users.