Let’s Clear The Smoke

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Author – Dave Hannah

For the last year the American public has been deluged with misleading claims regarding the EPA wood heating NSPS regulation proposals. 

This article is a sincere effort to correct the misleading information claims and provide the reader with relevant facts to better understand these proposed regulations affecting the wood burning industry and the public’s need for a remedy to high home heating costs.

The EPA is not attempting to ban woodstoves.  However, some of the pictures used by the EPA of wood smoke engulfing residential neighborhoods right next to the word “woodstove” grossly misleads. These pictures represent older, exempted wood boilers that were never subject  to emission EPA standards by the EPA. EPA’s current proposals would not affect these older, exempt woodstoves. The public should not assume wood stoves currently sold produce this menace!

The first attempt by the EPA to regulate wood stove emissions came in 1988. These standards established limits on the grams of particulates per hour that wood stoves would be allowed to emit to be considered EPA Certified clean burning.  Wood stoves employing catalytic damper technology were limited to 4.2 g/hr. and non-cat EPA technology certified stoves were allowed to emit 7.5 g/hr.  For better than twenty years, these regulations improved the wood smoke emission pollution for these types of stoves. 

However, there were large groups of wood heating appliances that were exempt from these regulations.  These exempt stoves are lower priced because there was never any requirement by the EPA to have manufacturers improve their burn efficiency.  Another category of appliance is the outside wood boilers.  These appliances were never required to meet any reduced particulate reduction like their relatives, the woodstove. 

It is these two categories of wood heating appliances that are the major contributors of excessive wood smoke. Woodstoves produced prior to 1988 continue to be the primary contributors to localized woodstove smoke. Any effort to reduce these localized problems will be ineffective unless they encourage replacement of the older, unregulated  stoves with newer, regulated, less polluting models.

I am very enthusiastic about the new EPA NSPS regulation that will no longer exempt these two types of wood heaters and require each of these categories to demonstrate a significant emission reduction to continue to be sold. 

The hearth product and chimney service industry each support the EPA’s effort to reduce smoke emission from stoves and improve total efficiencies.  There is a consensus of support for Phase I of the new NSPS standard that would require woodstoves to be limited to 4.5 g/hr.  While cat stoves appear to perform better in laboratory testing, in the real world they are less effective due to operator variances in behavior and quality of fuel used.

While limits less than 4.5 g/hr. may sound like a good idea, there is no reliable way to measure emissions at such low levels.  Thus, setting a limit at any level less than 4.5 g/hr. would simply be a feel good exercise. Establishing such a limit, with no reliably accurate test method, would remove the manufacturers’ ability to produce stoves that can reliably demonstrate compliance with the limit. Simply put, their businesses would be subject to the whims of an unrealistic test method.  Having a business exist on such uncertain ground will discourage investment in wood stove businesses and, as a result, eventually it would lead to the closure of many wood stove manufacturers.

This concern is proven research conducted by Rick Curkeet, PE Chief Engineer – Hearth Products Intertek Testing Services and documented in a 2010 study report that reveals the wood emission test labs cannot consistently achieve repeatable results when the required test result is below 4.5 g/hr.  The study demonstrates the unreliability of the test results. When the same stove is retested a different result is attained.

The EPA had originally agreed that a reasonable update to the NSPS would be to replace the existing limits of 7.5 and 4.2 g/hr. for non-cats and cat stoves, respectively, to a single 4.5 g/hr. requirement. Then, suddenly and without any new justification, the EPA lowered its proposal to 1.3 g/hr.  Additional complications were added when a change of fuel type was recommended after the original test and the industry has no experience with this new fuel type requirement for the test.

The hearth product industry would be subjected to millions of dollars of new development and testing cost with no certainty their stoves would satisfy these lowest requirements.  This would translate into a considerable increase in the cost of a new stove when the public is seeking relief for the high heating cost of 2014.  Many homeowners have and will continue to swap out their older, non EPA Certified stoves, for a new EPA Certified stove, if the price does not escalate.

The air quality will be greatly improved by the public swapping out older stoves for newer less polluting models.  The new standard of 4.5 g/hr. for wood stoves will reduce tons of particulates from the air without significantly impeding the replacement of old stove with new, clean stoves.  The removal of all exempt stoves and the requirement of certified emission wood boilers will go a long way toward the EPA’s overall goal of cleaner air.

The EPA is still open to hearing public comments on the new NSPS proposed regulations by contacting Wood.Gil@EPA.gov by May 3rd

~ Dave Hannah

Let’s Clear The Smoke  is reprinted with permission from

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