EPA finalizes NSPS for residential wood heaters

By Erin Voegele | February 04, 2015

The U.S. EPA has published a final rule establishing new source performance standards (NSPS) for residential wood heaters. The rules limit the amount of pollution that wood heaters manufactured and sold in the future can emit.

According to the EPA, standards for wood heaters were last updated in 1988. The new standards, finalized Feb. 4, reflect significantly improved technology that is now available to make a range of models cleaner burning and more efficient. The EPA also stressed the new rule does not affect current heaters already in use in homes today and does not replace state or local requirements governing wood heater use. Rather, the agency said the new rules will ensure that consumers buying wood heaters in the U.S. in the future will be able to choose from cleaner-burning models.

The new rule, however, does set the first-ever federal standards for hydronic heaters, wood-fired forced air furnaces, pellet stoves and a previously unregulated type of wood stove called a single burnrate stove. The rule does not cover fireplaces, fire pits, pizza ovens, barbecues or chimineas.  It also does not cover masonry heaters. While the EPA had proposed to set emissions limits on masonry heaters, it is not taking final action at this time to allow additional time for the development of emissions testing methods used to determine compliance. According to the EPA, it will consider whether to finalize requirements for new masonry heaters in the future.

In a statement, the EPA said the new rule will result in emissions from new models being reduced by approximately two-thirds, which is estimated to provide $3.4 billion to $7.6 billion in public health benefits. Those who purchase the new stove models will also benefit from efficiency improvements, which mean they will need less wood to heat their homes.

The EPA estimates the rule will reduce fine particle and volatile organic compound (VOC) emissions from heaters covered by the rule by nearly 70 percent, with carbon monoxide emissions reduced by 62 percent.

Standards will be phased in over a five-year period. For woodstoves, pellet stoves and hydronic heaters, the rule will be phased in in two steps, with the first set of requirements taking effect 60 days after the final rule is published in the Federal Register and the second limit taking effect in 2020. For wood-fired forced air furnaces, the final rule requires wood practice standards beginning on the effective date of the rule, with emissions limits phased in in two steps between 2016/2017 and 2020, to give manufacturers the time they need to develop cleaner models and conduct emissions testing. Small forced air furnaces will have to meet step one emissions limits by 2016. Large forced air furnaces will have an extra year to meet step one requirements, with compliance required in 2017. All forced air furnaces are required to meet the step two emissions limit by 2020.

The EPA has set step one emissions limits for new woodstoves and pellet stoves as 4.5 grams of particulate matter (PM) per hour of operation for catalytic and noncatalytic stoves. The step two PM limit is 2 grams per hour for catalytic and noncatalytic stoves if emissions are tested using cribs or 2.5 grams per hour if tested with cord wood using an EPA approved method.

The step one PM limit for hydronic heaters is 0.32 pounds per million Btu heat output (weighted average) with a cap of 18 grams per hour for individual test runs. The step two limit is 0.1 pounds per million Btu heat output for each burn rate if testing with crib wood. If testing with cordwood using an EPA approved method, the step two limit is 0.15 pounds per million Btu heat output for each burn rate.

For forced air furnaces, the step one operational/work practice standards take place 60 days after the final rule takes effect. The step two limit is 0.93 pounds of PM per million Btu output, weighted average and cordwood testing is required for forced air furnaces. For small furnaces, the step two requirements go into effect in 2016, for large furnaces they go into effect in 2017. The step three emissions limit of 0.15 pounds of PM per million Btu heat output for each individual burn rate takes effect in 2020 and also requires cordwood testing.

In a fact sheet, the EPA described several changes made between the proposed rule and the final rule. In addition to changes made regarding masonry heaters and the implementation timeline for forced air furnaces, the final rule changes the step one emissions cap for hydronic heaters. The cap now matches the current requirements of the agency’s voluntary Hydronic Heaters Program. The change allows most models that are phase two qualified under the voluntary program to be automatically certified as meeting the first emissions limit in the final rule.

To reduce potential certification delays, the EPA said it will allow conditional certification for up to one year for wood stoves, pellet stoves and forced air furnaces if a manufacturer submits a complete certification application that includes a full emissions report by an EPA-accredited laboratory and meets other application requirements.

The final rule also allows retailers to sell woodstoves that meet 1988 requirements and for hydronic heaters through the end of the year. After that date, new woodstoves and hydronic heaters sold at retail must meet the step one emissions limit.

While EPA will not require emissions from wood stoves and hydronic heaters to be tested with cordwood rather than the crib wood, the agency will allow cordwood testing for woodstoves and hydronic heaters with prior approval. To encourage further development of cordwood test methods, the EPA is including a slightly higher step two emissions limit based on cordwood testing for woodstoves and hydronic heaters. Based on available data, the EPA said it anticipates the alternative limit would be at least as stringent as the emissions limit for crib testing. The EPA also indicated manufacturers can test using either cribs or cordwood in step two, and must meet the limit corresponding to the type of test they choose. However, manufacturers that test with cordwood for step one must meet the same emissions limit as those testing using cribs. In addition, any manufacturer that chooses to test woodstoves or hydronic heaters with cordwood will be allowed to voluntarily use a special EPA label that recognizes emissions from cordwood testing more closely reflect emissions from in-home use.

John Ackerly, president of the Alliance for Green Heat, told Biomass Magazine, that overall the final rule seems to be fair. There are some really good things in the rule, he said, and some bad things.

Ackerly noted the EPA sided with industry in allowing new requirements for forced air furnaces to be phased in at different times for large and small furnaces. “That is one example where industry lobbying on the Hill really paid off,” he said.

Ackerly also called the 2 grams per hour limit for stoves fair and do-able, noting that’s what his organization predicted. “Over five years who knows what kind of innovation will happen, and that will enable stoves to hit 2 grams pretty easily without driving up the costs,” he said, adding that the rule will likely result in a lot more catalytic stoves.

According to Ackerly, the Alliance for Green Heat is disappointed and surprised by the EPA’s decision to get rid of the consumer hangtag. “Now, when consumers go to the showroom floor, there is no hangtag that they can easily use to compare stoves,” he said. However, the agency is allowing a voluntary hangtag for stoves that meet the 2020 emissions standards.

The Hearth, Patio & Barbecue Association has also weighed in on the EPA’s final rule. “Based on what we have heard from the agency, we believe that EPA has addressed a number of our concerns with the initial proposal,” said Jack Goldman, president and CEO of the HPBA. For example, we applaud EPA’s recognition of the critical need for transition relief for warm air furnaces.  While the devil is in the details, EPA appears to have allowed warm air furnace manufacturers time to develop and certify models to the new step one standards.”

“Conversely, we believe the agency missed the mark in other areas,” Goldman continued. “For example, some of the future standards proposed for wood-burning appliances do not meet the government’s duty to set standards based on data that shows both a tangible benefit to consumers and cost-effectiveness.  From what we have learned from EPA about the final rule, the new standards for cordwood performance are of particular concern, since the agency appears to have acknowledged that there are no cordwood test methods yet for many appliance categories, much less data using such test methods.  Both are needed to set standards – even optional standards.

“To be clear, our industry does not oppose new emission standards” Goldman said. “We simply want to ensure that these future standards produce a real clean air benefit that consumers can afford.  We will continue to work with EPA and other stakeholders to address our remaining concerns.”

The Pellet Fuel Institute expressed concern with the language EPA used in the rule. “PFI has significant concerns that the current EPA language – allowing for U.S. pellet producers to choose among multiple standards programs – will cause more confusion than clarity among manufacturers, retailers and consumers as they try to grasp what the different programs and fuel standards mean,” said Jennifer Hedrick, executive director of the PFI.

“We are surprised that EPA did not choose the PFI Standards Program as the sole program for U.S. pellet manufacturers, despite the fact that the Pellet Fuels Institute has maintained a fuel standard for over ten years and strengthened its testing requirements in more recent years at the specific directive of EPA,” she continued.

“We are particularly disappointed and troubled that EPA has changed course and will now allow standards that do not incorporate the very components, such as routine testing, that EPA publicly stated were essential requirements of any fuel standard to be included in the NSPS rule,” Hedrick said.

A full copy of the final rule and various fact sheets on the new requirements can be downloaded from the EPA website