Cordwood testing in Vermont. (Photo by Valley News)

Cordwood testing in Vermont. (Photo by Valley News)

(by Seth Partridge, NJDSAF Science and Tech. Committee)

According to results from the 2011 US Census, approximately 2.4 million people (or 12% of homes) use wood to heat their homes and this number is on the rise. As the negative impacts of emissions are increasingly recognized, the United States Environmental Protection Agency (EPA) has developed new rules for allowable emissions from woodstoves and pellet stoves. In brief:

  • These rules were effective 02/03/15.
  • Strengthens the emission standards for new woodstoves, outdoor and indoor wood-fired boilers, indoor wood-fired forced air furnaces, and single burn-rate woodstoves.
  • Fireplaces, pizza ovens, fire pits, barbecues, chimineas, and masonry heaters will not be covered.
  • The New Source Performance Standards (NSPS) will be phased in over a period of five years.
  • The rules apply to new wood heaters only.

The EPA believes that the new standards will result in a two thirds reduction of emissions in new stoves (70% reduction in volatile organic compounds and 62% reduction in carbon monoxide emissions) and that there will be $3.4 to $7.6 billion dollars in public health benefits.   New standards will also lead to more efficient burning, resulting in lower amounts of wood needed to heat the home.

Step 1 of the new standards starts sixty days after the final rule is published in the federal register. Retailers have until 12/31/2015 to sell existing inventory. The particulate matter (PM) limit will be 4.5 grams per hour for catalytic and non-catalytic stoves. Small furnaces will have to meet this limit by 2016 and large furnaces will have to meet this limit by 2017.

Step 2 will begin five years after the effective date of the final rule and the PM limit will be 2.0 grams per hour for catalytic and non-catalytic stoves.

Under previous regulations the stoves were tested using crib testing. This is a pile of lumber that has been assembled in a standardized configuration based on the type of heater being used. The new regulations encourage cordwood testing, which is more similar to real world conditions.   Currently there is a lack of data regarding cordwood testing and standards for cordwood testing are currently being developed. The primary concern of manufacturers is finding a balance between tangible benefits to consumers and cost-effectiveness.

Compliance will be determined by testing and certification. Conditional certifications will be allowed for up to one year and after that internationally accredited laboratories and certification bodies must be used for testing and certification.

Overall, it appears that these new standards will be good for the industry due to current negative perceptions about wood heat and air pollution. Concerns exist around testing methodology but the standards appear attainable at a reasonable price point. Interaction between the EPA and stakeholders has resulted in what appears to be a reasonable standard for future PM emissions.


Summary of Requirements for Woodstoves and Pellet Stoves from EPA website

EPA Finalizes NSPS for Residential Wood Heaters from Biomass Magazine 02/04/2015,