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Vermont Department of Environmental Conservation


US EPA Incentivized Voluntary Program

US EPA "Incentivized Voluntary Program": In coordination with NESCAUM, USEPA officials from RTP in North Carolina developed an "Incentivized Voluntary Program" to encourage OWB manufacturers on a nationwide basis to reduce emissions from newly manufactured OWBs. EPA involved stakeholders during meetings and conference calls to develop emission "guidelines", a test method, labels and an implementation time line. Stakeholders included hydronic heater (OWB) manufacturers, the Hearth Patio and Barbecue Association (HPBA), state regulators, NESCAUM and Environment Canada.

EPA has more recently expanded its voluntary program to include wood and other biomass pellet boilers and indoor boilers, renaming this endeavor the EPA Hydronic Heater Program. Under this program, any manufacturer whose hydronic heaters are tested and shown to be capable of meeting EPA's prescribed voluntary emission guideline will be allowed to display a label on each heating unit that it meets EPA's criteria.

The implementation of the voluntary program involved multiple phases with increasingly more stringent particulate emission goals. For phase I of the program, the voluntary particulate emission guideline selected by USEPA was 0.6 pounds per million BTUs (lbs/MMBTU) of heat input. This number was in the same general range as the limit set by Vermont's Phase I rule (0.44 lbs/MMBTU of heat input). The US EPA Phase 2 guideline of 0.32 lb/mmBTU of heat output was announced by EPA at a ceremony here in Vermont on October 23, 2008. The test method developed by EPA to measure the particulate emissions from OWBs is: "Test Method 28 WHH for Measurement of Particulate Emissions and Heating Efficiency of Wood-fired Hydronic Heating Appliances". This test method is a modification of EPA Method 28 used for the laboratory certification testing of indoor woodstoves.

On February 3 2015 the EPA promulgated a new regulation for wood heaters, the residential wood heater New Source Performance Standards, which applies to all types of residential wood heaters, including OWBs. The effective date of this regulation was May 15, 2015 and once implemented will require certification of OWBs by the EPA.

Details of the EPA voluntary program, a list of EPA qualified Hydronic Heaters and other information about wood-fired hydronic heaters can be found on this EPA website:

EPA - OWB/WHH website  ||  The EPA Test Method 28 WHH



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