Demand for automation in wood stoves moves forward in Europe, but could be sidelined in the U.S.

Updated July 18 - The newest type of stove on the market is the automated or ‘smart’ stove that use sensors and computer chips to adjust airflow, instead of relying on the operator. Automated stoves enable the operator to "load and leave," allowing the stove to maximize efficiency and emissions reductions on its own. These stoves are likely to be the next major step towards cleaner residential wood heating because it is well-known that poor operation by the consumer is one of the main reasons for excessive smoke, and often it is the main reason. 

Automation does not just seek to address poor operation by the consumer.  It also can assess variable draft conditions caused by different chimney configuration, the altitude of the home, and the moisture content of the wood.  In addition, automated stoves are often interactive, helping to educate operators through visual prompts or detailed apps on smart phones. 

 

In Europe, automated stoves have been advancing far more quickly and are recognized as by the regulatory community as an important solution.  In the U.S., the EPA and other agencies are focusing on an equally important process - improving test methods for manually operated stoves – with little attention to automation. Improved test methods still leave manually operated stove vulnerable to wildly variable real-world emissions.  

 

Outside of regulatory circles, automated stove technologies have been promoted in the U.S. by the Wood Stove Design Challenge, a series of technology competitions, and by funding from the US Department of Energy in association with national labs.  A 2023 study from Brookhaven National Lab described the technology as “a minimal set of measurement sensors and a heuristic control strategy to actively modulate incoming air to enhance stove combustion performance, thereby eliminating user-error as a factor for emissions production.” More recently, researchers at Oregon State University and Aprovecho Research Center are focusing on automated technologies that show PM reductions up to 95% compared to older models

 

The first such stove on the US market, MF Fire’s Catalyst, launched in 2016, is now off the market. The second, Charnwood, a British manufacturer entered the US market in 2020 with their Skye E2700. The company say, “This stove uses Charnwood I-Blu combustion intelligence that continuously monitors the state of the fire and optimizes efficiency while reducing emissions through real-time adjustments. Air is introduced in just the right amounts, in the right places, at exactly the right time to ensure a cleaner, highly efficient burn.”

 

A third manufacturer, Pacific Energy has added automated technology to three of their stove models. The Neo 1.6 LE2 and the larger NEO 2.5 LE2, both of which come in freestanding and insert models. Under their True North brand, the TN25 C, they use the same technology on a hybrid stove with a catalyst that is continuously engaged, and does not have a damper control. According to an email from Pacific Energy, they use an “algorithm controlling two sources of supplemental air, working in the background to seamlessly improve combustion.  This patent pending technology uses two probes to monitor the firebox and the flue temperatures. Based on the absolute, delta and the rate of change in temperatures, the combustion is being optimized at all times.”  Pacific Energy markets these stoves as regular wood stoves without explaining the details of their automation to the consumer. 

 

The Canadian manufacturer SBI won an award at the 4th Wood Stove Design Challenge for their progress toward an automated stove and they received a grant from the DOE to develop it. A final version of it is expected to be EPA certified and on the North American market later in 2025. 
 
Automated stoves on the European market
In Europe there has been far more R&D and diversity of automated stove technology.  Notably, in Europe, manufacturers highlight the environmental benefits of automation to the public and to the regulatory community. Models include: 

 

Hase, Lima IQ (Germany)

Hwam SmartControl (Denmark)

Nordica, Larissa (France)

Rika, Rikatronic4 (Austria)

Scan Zensoric Technology,  (Denmark)

Xeoos Twinfire Blue (Germany)

Wodtke, Stage F (Germany)

Full vs. partial automation.  There are many ways to automate a wood stove and one of the main variables is whether the stove still has air levers that the operator can control.  If the stove has controls for the operator, it is virtually impossible to tell if the automation can override the operator, or vice versa.  Many consumers, particularly in North America, want to at least have the sense that they can control air flow, which is key to heat output.  Otherwise, control of heat output can be with the amount and frequency of wood that is loaded into the stove. Also, there is always the question of whether and how well an automated stove works during a power outage.  Most, if not all, can work, but will do so sub-optimally. 

Bi-metal springs that have been used for decades in stoves produce a very modest amount of automation to stoves, and they can be used in conjunction with electronic automation strategies.  

Other features. Some stoves have a LED light that will come on when its time to reload the stove.  Some are connected via wi-fi apps and can produce a sound to prompt the consumer when to reload. The Austrian company Rika has a feature where you load firestarter in the tray, add wood, and then you can program the stove to start remotely, as pellet stoves can.

Aftermarket solutions. Several companies have built devices that can monitor and/or control the airflow of existing stoves or be integrated into new stoves.  Maxitrol is a leading supplier and makes the battery powered “E-Flame air control system” that drives an actuator to control primary and secondary air flow.  It was designed in part to help companies meet future European EcoDesign Directives.  The Danish stove manufacturer Aduro has had it’s Smart Response on the market for several years. The app-connected thermometer provides feedback to the consumer on their smart phone about whether their stove is burning well, and how to improve its use.  Baltimore-based MF Fire is working on something similar. These technologies do not automate stove functions but monitor conditions and prompt the user to give the stove more air, add wood, clean their chimney, etc. 

Regulations and incentives to automate: In the United States, there is little regulatory pressure or incentives for manufacturers to automate.  The new Integrated Duty Cycle (IDC) test protocols are designed so that all types of stoves can be tested and to our knowledge the test method was not designed so that automated features would help a stove pass, though it is possible that will be the case. It is imperative that the National Residential Heating Task Force test the automated stoves on the market in the U.S. and give them the profile that other stove types are getting.  Currently, the test regimen may show the benefits of catalytic and hybrid stoves in the lab, without sufficient data or attention to how well cat stoves are used and maintained over their 10 – 20 year lifetime.  Automated stoves may also have maintenance issues over their 10 – 20 year lifespan, and it’s important to start assessing which automation strategies are more robust.

Test protocols are perhaps the best way to encourage manufacturers to innovate.  Protocols can make it harder for manually operated stoves to pass by requiring air adjustments that are likely to produce more smoke, unless sensors in the stove can adjust airflow themselves.  Making certification marginally tougher for non-cats to pass, leading to a growing percent of catalyst and hybrid stoves, is not an ideal solution compared to growing the number of automated stoves on the market.

At the state level, change-out and other incentive programs can start to recognize automated stoves and give them higher incentives.  Massachusetts is the only state that sought to provide incentives to automated stoves in a change out program in 2017 but it came too early and automated models were delayed coming on the marketplace.  States and air agencies can start to make consumers aware of this new type of wood stove, along with catalytic, non-catalytic, hybrid and pellet stoves. 

The lack of attention and support for the development of automated stove technology in the United States is connected to similar lack of support for cleaner pellet heating appliances.  Despite the ability of pellet stoves to emit very low levels of PM, the EPA allows them to emit the same level of PM as wood stoves, even though they have a different type of fuel, which should lead to stricter emission standards. In Europe, the EcoDesign Directive of 2022 requires pellet stoves to emit only half of what wood stoves are.  

The lack of “eco” or “green” labels for wood stoves in the U.S. has left manufacturers with little incentive to produce cleaner or automated stoves.  In Europe, some eco labels require pellet stoves, for example, to produce a quarter of the PM of wood stoves, and half of regular pellet stoves.  Manufacturers selling on the US market have mainly focused on achieving 75% efficiency, in order to qualify for the tax credit under IRS Section 25C.  Congress revoked that section, effective Dec. 31, 2025 and its unclear if it will be a permanent revocation or just for several years.  The credit has often lapsed since 2005, when it first began.  In Europe incentives have steered away from residential log heaters and focused on the best pellet stoves and boilers, which is a possible path forward in the U.S.

In Europe, some manufacturers feel that is not if, but when, they will have to start producing automated stoves. There is more urgency in Europe because of more widespread use of wood stoves in cities like London, and densely populated areas of Denmark, Netherlands, France, Germany and other countries. The German Blue Angel label and more local regulatory efforts, such as in Berlin, have also led to far more innovation and R&D on automation.  As in the U.S., lobbying by industry is slowing efforts at national and local levels to pass stricter measures that could lead to quicker adoption of automated stoves and more reliance on pellet stoves.

In early 2025, the European Commission released draft language of a new directive to take effect in 2027, including language that automation in stoves would be required. This led to strong industry push-back, and work on the new directive has been delayed.  The European Committee of Manufacturers of Domestic Heating and Cooking Appliances stated:

 

“The requirement of for automatic combustion control systems, additional testing, second conformity contradicts Ecodesign principles: it increases costs, energy consumption and maintenance need, limits technological neutrality and makes appliances more expensive.”
 
“Any Ecodesign regulation should not favour specific technologies. It should be technology-neutral and allow manufacturers to choose how to meet the regulation's requirements…. Although not explicitly required, a stove without a built-in catalytic converter and electrostatic precipitator is unlikely to meet the emission requirements. All seven known Blue Angel stoves have these features.”

 

This industry response to the draft of the next European Directive has many valid points which will also be part of the landscape in North America.  Regulators on both continents should shift their focus away from manually operated stoves and address these concerns and others as they move toward next-generation solid fuel heating solutions. One European study found automation reduced PM by 66% compared to one test method.

 

 

More resources on automated stoves

 

Eurocities, “Cities call for stronger EU rules on new wood-burning heaters to tackle deadly air pollution,” June 2025

AGH Webinar, “Harnessing Electronics for Cleaner, Smarter Wood Heating,” June 2025

14th U. S. National Combustion Meeting, “Forced-draft Airflow Control Tuned to Reduce PM Emissions in a Cordwood Room Heater Under Variable Operating Conditions,” 2025

 

Chemical Engineering Reactions. “Reducing Emissions from Current Clean-Burn Wood Stove Technology by Automating the Combustion Air Supply and Improving the End-User Interaction -Two Important Primary Measures,” 2023

 

IEA Bioenergy, “Design of Low Emission Wood Stoves,” 2022

 

Tarm Biomass, “Automated Wood Stoves: Technology Policies and Barriers,” 2017

 

Technical University of Denmark, “Guidelines for automated controls for wood stoves,” 2017

 

AGH Blog, “Automated stoves entering the marketplace,” 2014

 

AGH Blog, “Nine reasons manufacturers don’t use sensors in wood stoves,” 2013

IRS proposes using EPA database to verify 75% efficiency for tax credit

Industry is split three ways on question of eligibility.

July 2025 update: Congress revoked the wood heater tax credit as of Dec. 31 2025, ending what was meant to be a 10 year extension under President Biden. Expenses are eligible for stove purchases and installation of stoves prior to Dec, 31. 

Nov. 2024 - The IRS issued a proposed rule on October 25 to give guidance on how manufacturers can interpret“75% efficiency.” They are proposing to adopt the EPA database as the means of determining efficiency, which has been long expected by many in industry. 

The proposed rule is long-awaited by many who grew frustrated over the years that the IRS could not do what many felt was obvious: recognize the EPA efficiency listing. AGH was a prominent advocate for a uniform way to list efficiency as a way of protecting consumers, making a level playing field for manufacturers and instilling more faith in the industry. AGH often publicized exaggerated and misleading efficiency claims over the years.

Comments to this IRS notice are due by December 24, 2024 and a hearing is scheduled for January 21, 2025. The IRS notice can be found here.

Congress stipulated that biomass heaters at 75% efficiency, using the higher heating value, were eligible for a 30% tax credit, up to $2,000. However, Congress revoked that as of Dec. 31, 2025.

Most manufacturers were already using the efficiency numbers on the EPA database as the arbiter of which stoves or boilers were 75% efficient or higher. The EPA number is an average of the efficiencies on all the certification tests. But a few manufacturers chose to say their stoves qualified for the tax credit if any of the certification tests were 75% or higher.

The third faction, made up of masonry stove manufacturers, urged the IRS not to issue any further guidance, so that they could claim masonry stoves at 75% or higher could qualify even though they are not listed on the EPA database because they are not required to be EPA certified.

According to the Congressional Research Service, approximately 48,300 taxpayers claimed the biomass tax credit in 2023, making it the least likely tax credit that taxpayers claimed other than for home energy audits. There is no public data on how many biomass stoves and boilers were sold in recent years, but experts say that an average of 200,000 is plausible. EPA has the data but it is not organized or compiled.

Currently 67% of the 101 certified pellet stoves are 75% or higher, based on the EPA database figures and 45% of wood stoves are. However, 92% of cat and hybrid stoves are 75% or higher and only 15% of the 106 non-cat stoves on the market are 75% or higher.

The legacy of using efficiency to qualify for this tax credit, that started in 2008, raises many questions. Arguably, cleanliness is more important than efficiency when using wood, a renewable fuel that a substantial percent of Americans cut or collect on their own instead of purchasing it. The result is that stove manufacturers now focus more on efficiency, while sacrificing R&D to achieve incremental reductions of particulate matter. Congress controls the efficiency number, while EPA sets emissions levels, and a lower efficiency threshold could allow the EPA more leeway to set stricter emissions standards.

Most manufacturers did not submit comments on the proposed regulations. All comments can be found here. Among stove manufacturers, some manufacturers who make lower efficiency stoves (e.g. US Stoves) argued for the stricter definition of efficiency, while those making higher efficiency stoves (Hearth & Home Technologies) argued for a more lenient definition.

The comments by stakeholders outside the wood and pellet heating community provide an interesting snapshot into views on incentives for wood and pellet stoves and boilers. For instance, the American Lung Association does not support biomass stoves or boilers should be qualified energy property regardless of efficiency rating. The California Air Resources Board (CARB) and the Attorney Generals of MA, CO, DE, IL, ME, MD, MI, NJ, NY OR, RI and DC believe a full carbon lifecycle analysis should be done to better calculate an efficiency rating.

However, based on their comment and the sources in the footnotes, it appears that they are confusing biomass to electricity, rather than focusing on biomass heat. While this is a common mistake in the media, it is notable that whoever drafted this comment for these states also made it. Nevertheless, these states do not oppose the tax credit but argue that a stricter one could be better. No commentator suggested that only pellet heaters, that are consistently cleaner and more efficient, should receive the tax credit. A carbon life cycle analysis however, would most likely favor cordwood over pellets.

Support using EPA database

Alliance for Green Heat: The most reliable method to protect consumers, ensure that tax credits are
going to compliant models and create a level playing field for manufacturers is for Treasury/IRS to specify that eligibility is limited to units listed in the EPA Certified Wood Stove Database that have an overall weighted average efficiency of 75% or more using the higher heating value of the fuel. (AGH’s full comment can be found here.)

BPA, ACEEE, ASE: The most reliable method to protect consumers and to ensure that tax credits are going to compliant models is for Treasury/IRS to specify that eligibility is limited to units listed in the EPA Certified Wood Stove Database as having an overall efficiency of 75% or more using the higher heating value of fuel.

Blaze King: Our company has always viewed the overall efficiency to be the metric intended by the IRS as the qualifier for the 75% high heating value.

Travis: In the interest of efficiency and the preservation of resources, the IRS should rely on EPA’s database to confirm whether biomass stoves meet the 75 percent rating requirement.

US Stove Company: Therefore, for a biomass stove or boiler regulated by the EPA to qualify for the 25C credit, only the average “overall efficiency” is reported in the EPA Certification report should be recognized. In addition, this same efficiency number will be posted on the EPA Wood Heater Database, therefore easily verifiable. This will eliminate any question or “gaming” of the tax credit.

Support using any single test run

Hearth & Home Technologies: In our view, the Treasury Department and the IRS should issue guidance stating that biomass stoves meet the definition of "qualified energy property'' provided they have a "a thermal efficiency rating of at least 75 percent (measured by the higher heating value of the fuel as reflected in a single certified test run)." Providing this guidance will resolve the current uncertainty about how to meet the HHV requirement. By establishing the single test criteria, a greater number of biomass stoves could qualify for the tax credit, thereby giving consumers more affordable choices to replace noncertified heaters while burning an efficient renewable energy source.

Stove Builder International: Manufacturers should be able to qualify a property …provided this efficiency number is 75% or greater and can be found in the property’s test report. An efficiency number of 75% or greater should be obtained when the property is used at a combustion setting typically used by consumers. For instance, in the case of a wood stove, the products are typically used by consumers at the low setting. That is, consumers use their stoves in slow-combustion mode to get an “overnight burn”. The stove can be used at a higher setting, but this setting is normally recommended upon start-up only. The basis of their argument is that manufacturers will “make up any number they want.” This could not be farther from the truth. We don’t know where this paranoia comes from.

If the efficiency criteria do not offer enough flexibility and most non-catalytic wood stoves cannot qualify for the 25C tax credit, we feel that the IRS misses its objective of helping the middle class to switch to cleaner, more efficient biomass appliances.

Support current language without further guidance

Masonry Heater Association: the IRS not to issue guidance that conflates the regulations of different types of biomass heaters, potentially imposing the requirements of one category of biomass heater onto another category, for tax credit eligibility. For example, woodstoves must be on the EPA's certified list, EPA Wood Stove Database, to be legally installed; however, this is not a legal requirement of all categories of biomass heaters, e.g. masonry heaters. Masonry heaters are a category of biomass heating appliance that the EPA has chosen to defer regulating.

Tulikivi: we feel that guidance is not needed as the original text is clear enough and allows masonry heaters that meet the efficiency requirement to qualify for the tax credit despite not being on the EPA list of certified appliances

Support strict enforcement based on efficiency tiers

Comments Of The Attorneys General Of Massachusetts, Colorado, Delaware, Illinois, Maine, Maryland, Michigan, New Jersey, New York, Oregon, Rhode Island, And The District Of Columbia; The California Air Resources Board; And The Ramsey County, Minnesota, Attorney: With respect to Section 25C’s biomass provisions, we urge Treasury and the IRS to strictly enforce energy efficiency tiers to verify qualification for biomass stoves and boilers. Per British thermal unit (BTU), wood has about the same carbon content as coal, and, according to EPA, wood contains about 75% more CO2 per BTU than natural gas. As a result, wood that is harvested and burned for energy immediately increases greenhouse gas emissions—even where it is displacing fossil fuels. Biomass combustion also emits other harmful air pollutants, like particulate matter, which is connected to a multitude of adverse health consequences including premature death, cardiovascular effects, asthma, bronchitis, pneumonia, chronic obstructive pulmonary disease. To avoid inadvertently increasing greenhouse gas and other harmful pollutant emissions through biomass incentives, Treasury and the IRS should comprehensively evaluate lifecycle greenhouse gas emissions in calculating the efficiency rating of eligible biomass. If, however, Treasury and the IRS elect to rely on EPA wood stove certifications to demonstrate efficiency ratings, they should not allow certification based on test methods 125 and 127 (relying on ASTM 3053), which allow too much variability and manufacturer and laboratory manipulation.

Do not support including biomass heaters in the 25C tax credit

American Lung Association: The ALA recognizes that pollution from the combustion of wood and other biomass sources poses a significant threat to human health and supports measures to transition away from using these products for heat production. As such, we do not believe biomass stoves or boilers should be considered as part of a qualified energy property regardless of efficiency rating.

Other comments

Governor’s Office of NJ: Biomass stoves and boilers are a concern. It’s likely we would have difficulty supporting incentives for biomass but there may be cases that make sense.

Rewiring America: Treasury should structure the updated Form 5695 such that each product category (heat pumps for space heating/cooling, heat pump water heaters, biomass stoves, and biomass boilers) has its own line and can be tracked accordingly. This is crucial to track how many claims are filed for heat pumps and heat pump water heaters; otherwise, it would be impossible to distinguish between claims filed for heat pumps and biomass products.

EPA watchdog issues second stinging report on the EPA’s wood heater program

The EPA’s Office of Inspector General found continued lack of enforcement of the EPA wood heater regulations, more than a year after its first major investigative report found similar issues. Unlike that in-depth report, this new report cites very specific details of instances where manufacturers and labs have violated EPA regulations.  It found that even when the EPA knew of significant violations, it did not take action to correct the problem.  

The wood heater manufacturing and test lab industry is a collegial community where members rarely publicly criticize other members, even when major violations of the EPA regulations are widely known. However, manufacturers often relay private complaints about their competitors to the EPA, putting the EPA on notice of a wealth of compliance issues.

“We call on EPA leadership to provide more resources toward the wood stove program and address systemic enforcement issues,” said John Ackerly, President of the Alliance for Green Heat. “Its also vital for the public to know that pellet stoves are not involved in much of this controversy and that many wood stove manufacturers make good products, follow the law and are being undercut by those who knowingly skirt regulations,” Mr. Ackerly said.

Over the last 15 years, the only entity that has consistently published specific instances of non-compliance is the Alliance for Green Heat (AGH) in its monthly newsletter, and on its website.  Like the EPA, AGH is often contacted by industry members who are troubled by the conduct of other members.  The OIG listed five instances of abuse that the EPA overlooked and failed to take sufficient action, but there are scores more.  For instance, the internet continues to be rife with the sale of uncertified wood heaters, including outdoor wood boilers, which the EPA has known about for years, and appears not to have done anything.

  

US Stove sold 4,321 stoves before they were certified

This week’s report from the OIG follows up on several high-profile cases that AGH has pressed the EPA to address, including widespread fraud at US Stove Company which the EPA has been silent on for 5 years. In that case, an employee of US Stove was outraged and blew the whistle on his company.  US Stove then sued the whistleblower, getting a Temporary Restraining Order (TRO) against him to shut him up, which the local Tennessee court said was “in the public interest.” 

 This week’s OIG report described how US Stove manufactured and sold 4,321 stoves before they were certified, and d859 of them were sold even before the test lab started testing the unit. Though the EPA had all of these details, it did lead to further action.

The stove in question was never officially recalled by the Consumer Product Safety Commission.  A list of wood and pellet stove recalls can be found here.

A second whistleblower came forward, providing extensive details of fraud to the EPA, imploring them to take action.  That person wrote: “To those of us who refused to cooperate with this fraud [at the US Stove Company], we had hoped that the EPA would step in, enforce its regulations, and thus provide some level of protection and dignity to whistleblowers. I expect US Stove may come after me, and possibly file a lawsuit against me, as they did with the first whistleblower. The company has dragged that man through the mud, and forced him to hire expensive lawyers, just because he was willing to stand up for EPA regulations.”

False advertising of efficiency

Another major issue that AGH has pursued over the years is false or misleading advertising of efficiency levels, often telling consumers that the unit is eligible for the IRS tax credit, which requires stoves to be 75% efficient, using the higher heating value (HHV). In one case, a test lab listed the stove at 70% efficient, but the manufacturer told consumers it was 75% efficient and eligible for the tax credit. The EPA sent the manufacturer a cease-and-desist request via email, which the manufacturer did not act upon.  The OIG report said the EPA could have revoked the certification of the stove but has not taken further action.  

 

False and misleading efficiency advertising was widespread up until 2021, when most manufacturers began to advertise the efficiency as reported by test lab, and listed in the EPA database of certified stoves. US Stove continued to falsely represent some of its units and declined to comment on the record. Stove Builder International, a large Canadian manufacturer insists that various interpretations of efficiency were acceptable until and unless the IRS defined “efficiency” more clearly. For example, some experts argue that if a stove reaches 75% efficiency on any official test burn, it can qualify even if the average efficiency of all four burns is less than 75%.

 

While the OIG vigorously raises the issue of false advertising of stove efficiencies, it is far from clear whether OECA even believes it has the authority to address efficiency.  Efficiency testing became mandatory in 2020 but the EPA began listing efficiencies in 2012. The EPA does not regulate efficiency, as most European countries do, allowing stoves as low as 51% efficient to be certified.

 

EPA lab served as own third-party certifier

One of the 5 incidents of concern in the OIG report included an EPA approved lab serving as its own third-party certifier of a test report it has produced.  Again, the EPA knew about this but did not revoke the certification and “the lab remained approved by the EPA.”  

 

Test labs are allowed to be third party certifiers and most of them are.  However, they cannot certify the results of stoves tested in their own lab.  PFS-TECO, Intertek, OMNI, RISE (Sweden) and SZU (Czech Republic) are both test labs and third-party certifiers.  PolyTest (Canada), ClearStak and the Danish Technological Institute are approved test labs but are not third-party certifiers. 

 

Deviation from test methods

A fourth concern raised by the OIG, which has already been resolved, involved Lamppa manufacturing who makes Kuuma wood furnaces.  Lamppa had obtained an alternative test method, but the test lab deviated from that method, due to complications.  The manufactured disclosed the deviation and explained why, and the EPA certified it anyway.  After 5 years, the EPA informed Lamp it would not recertify the unit, and Lamppa had to retest and recertify the unit.  

 

Recommendation to the EPA

 

The OIG listed several significant recommendations, some of which could be incorporated into the next set of wood stove regulations, known as New Source Performance Standards (NSPS), which the EPA is currently working on.

 

·      Including a federal criminal false statement clause into the wood heater certification application process, which would require manufacturers, but not necessarily retailers, to not make false statements in their advertising.

·      Develop procedures to revoke the approval of test labs that do not follow NSPS requirements.

·      Develop procedures to revoke the certification of wood heaters that do not coply with NSPS requirements.

·      Inform the OIG of investigations into fraud or abuse of the wood heater NSPS.

 The  OIG report can be found here. 

10 States sue the EPA to improve wood stoves, but the grounds are dubious

Old stoves removed during change out
programs range from ones like these ...

Ten states and one large air agency filed a notice that they intend to sue the EPA over its weak wood stove testing, certification and enforcement programs. The lawsuit is one of the only ways to keep the agency on the required timeline of updating its wood and pellet heater regulations every eight years. Otherwise, the agency can easily let timelines slip and put wood heater policies and regulations on the back burner as both Republican and Democratic administrations have usually done.

The Alliance for Green Heat (AGH) supports the lawsuit for these reasons: EPA needs to keep focused on this technology and keep doing the testing that can get better test methods and stoves that operate better in the hands of the consumer. Automated wood stoves that use sensors, computer chips and actuators to mix the fuel and the air, like in cars, probably offer the best hope for cleaning up wood stoves. But they may be left out of the next updated regulations, known as New Source Performance Standards (NSPS).

... to stoves that are decrepid
and/or dangerously self-installed.

However, AGH does not agree with much of the faulty narrative that says new stoves are not likely to be cleaner than old stoves. And maybe most worrisome is that the AGs of so many states appear willing to make such claims without citing data to support it. 

Unlike the dynamic around auto emissions, where car manufacturers are pitted against the EPA, in this case all fingers are pointed at the EPA for being too lax. The EPA’s wood heater program has had huge weaknesses and it is an easy target. But it is important to understand that the EPA is not a monolith, and it is the wood heater certification and enforcement programs in Washington that are far more of a problem than the section in North Carolina that does the test methods and change out programs.  

One of the many problems with the filing by 10 state Attorney Generals (AG) is that it is mainly based on a review of the EPA’s certification program done by the State of Alaska and Northeast   States for Coordinated Air Use Management (NESCAUM), with funding from New York State Energy Research and Development Authority (NYSERDA). It is not based on testing of new stoves in the field compared to old, uncertified stoves in the field. The narrative that the EPA has been wasting money on change-outs because new stoves aren’t necessarily cleaner than old ones seems to be gaining traction despite evidence to the contrary. Moreover, it distracts from the real, complex tasks at hand and is divisive. As a public relations strategy, it has been successful, gets good media coverage and rallies liberals.

The reality is far more complex. Ironically, it also misses what blue states care about: maximizing renewable energy in smart ways and creating more equity in the energy transition. Starting with the NESCAUM report, pellet appliances have been sidelined from the narrative and they are not even mentioned at a time when much of America is confused about the difference between premium heating pellets and industrial pellets to make electricity. If wood and pellet stoves are to play a role at helping the US reduce residential fossil fuel and protecting low to moderate income (LMI) households from the high costs of the new energy paradigm, it is vital for AG offices to understand the role of the technology in America. 

The Notice to Sue, likely leading to a lawsuit can be good for our common goals of getting cleaner wood stoves, but AG offices need to understand some things. First, we don’t need a new NSPS before we have new test methods. (One of NESCAUM’s many roles is providing data for new test methods, but compared to other labs, NESCAUM’s lab is way behind schedule, which complicates the whole timeline.) Second, the goal of getting better repeatability of a test result within a lab and between labs does not necessarily lead to a cleaner stove in the hands of homeowners. Third, tilting scales toward hybrid stoves may help in the short run, but is not necessarily a long-term or nationwide solution. Fourth, there has never been much agreement on what constitutes the best systems of emission reduction (BSR) in stoves which hinders the EPA in writing regulations that can force technology to change and improve. 

Wood and pellet heaters can help the nation in our transition to electrification by giving homeowners a back-up heating source, lowering stress on the grid during wintertime and providing LMI households protection from rising electricity costs which helps achieve equity. And environmental justice is improved in poor communities not just by a reduction in woodsmoke but also by improving energy security so that homes do not have to choose between heating and eating. For low-income households, change-out programs have been very important by removing unsafe stoves that pose a fire risk, improving not just ambient particulate matter (PM) and indoor PM, and adding heat pumps to many homes. 

The next NSPS will be best served by an EPA with the budget that enables them to collect their own data and properly manage the certification and enforcement programs, which are still far from effective. Underfunding leaves the EPA vulnerable to just reacting to one side or the other, and making poor decisions like revoking a cordwood test method that should have been changed and improved instead. That revocation was also prompted by the same group of states, most of which lack the expertise to understand the complexities and the politics of such a move. Tightening up that test method would have helped the EPA gather vital data it needs for this NSPS and not rely on data from parties who are sparring for an upper hand in the process.

The mostly blue states leading this lawsuit also need to manage wood and pellet heating far better in their own borders, as all states do. Vermont is a good model which is also heavily promoting heat pumps. States should be promoting pellet stoves and boilers and demanding stricter PM limits for those appliances. They should also limit the new installation of cord wood stoves in densely inhabited areas unless, or until, automation and mini-electrostatic precipitators can make cordwood units far cleaner. While cordwood stoves are essential for rural LMI households and help them get off fossil fuels, manually operated wood stoves are simply not a good energy solution where lots of homes are close together, particularly when the topography leads to frequent inversions, trapping PM close the ground where we breathe. 

As for the solution to reduce wood smoke in Fairbanks, even Albert Einstein would be scratching his head. Managers of that change-out program have done an admirable job and used many different strategies. They also uncovered huge problems in the EPA’s stove certification program which were hiding in plain sight. But we should not expect the next NSPS to make much of a dent in that intractable problem. 

Nationally, the solution lies in far more funding for R&D in stove technology, more attention to enforcement of current regulations, more experts for state AGs to rely on and collaboration. Like many big energy issues, the solutions are multi-faceted and rely on a collaborative approach by stakeholders. We should take this lawsuit as a wake-up call.

Reflections on the EPA Inspector General’s residential wood heat report

    The Environmental Protection Agency’s (EPA’s) internal watchdog, the Office of Inspector General (OIG) concluded that the agency does not have an effective program to test and certify wood stoves.  Much of the OIG's report tracks findings and positions of an earlier report by North East States for Coordinated Air Use Management (NESCAUM), which triggered the OIG report (NESCAUM 2021). But the OIG report has a level of authority over the agency and provides a roadmap for much needed changes.

    The OIG report finds extensive faults with the Office of Air and Radiation (OAR) and Office of Enforcement and Compliance Assurance (OECA) instead of laying blame with EPA leadership which for decades under both parties has failed to provide those offices with the resources and expertise they need to effectively do their job. Successive administrations have undervalued the vital role that wood and pellet stoves play, particularly for the rural poor, and also underappreciated the enormous levels of PM2.5 created by wood stoves. The United States has also failed to develop policies and invest in research and development (R&D) in this renewable energy technology that could be far cleaner.  

    The OIG did not break much new ground and wood heating insiders will not find much new.  Unfortunately, the OIG report also missed some of the same perspectives that NESCAUM missed, providing a one-sided view of many problems. Overall, the Alliance for Green Heat (AGH) agrees with most of the findings and the recommendations but is very concerned that the OIG, like the offices within the EPA that it criticized, may not have had the expertise to understand broader issues, other than ones raised by NESCAUM.  

    Both the NESCAUM and the OIG report consistently and incorrectly referred to “wood heaters” when they should have used the term “wood stoves.” Wood heaters include pellet stoves, a mainstream stove technology used by hundreds of thousands of consumers which do not share most of the problems wood stoves have and are a good alternative to wood stoves. The OIG failed to reassure consumers that pellet stoves can offer a cleaner and more trustworthy option. 

    Like the NESCAUM report, the OIG also failed to consider that the original test methods dating from 1988 may also be flawed and may not produce stoves that meet the PM2.5 emission standards.  We suspect that independent retesting of stoves using both test methods – Method 28  and ASTM E3053 - would find stoves emitting far more than the allowable emission levels.  

    The OIG’s quotable finding that consumers can still purchase stoves that failed EPA tests may gain far more traction with the media and environmental groups than it deserves. There is little evidence that those particular stove models are more susceptible to higher emissions than other models. Moreover, the dryness of the wood put into a stove and the amount of air the consumer gives the stove have an exponentially greater impact on emissions than which test method was used to certify the stove.  

    We do not agree with the assessment that EPA's funding for change-out programs should be questioned based on the NESCAUM or the OIG report. The managers of many of these change-out programs likely have far more expertise than the authors of the OIG and know all too well that changing out an old wood stove for a new one has limitations.  Many funds also go to bounty programs, education, pellet stoves, hybrid stoves and increasingly to heat pumps, not just new non-cat wood stoves.

    To get a broader perspective on these issues, we highly recommend reading an article about the experience of one manufacturer and their experience dealing with the EPA certification process as it rushed to respond and fix its system.

    Like the NESCAUM report, the OIG report did not consider the obvious option for the EPA to amend and improve E305, rather than revoking it. Neither report assessed the bigger picture of how ASTM E3053 could have been part of the effort to develop a federal cordwood test method by halting its use for 6 – 12 months, amending it and then gathering more data from it during certification testing. As a result, we have lost many years of manufacturers redesigning stoves that can better burn cordwood, instead of continuing to build stoves that burn cribs.

    Both reports are a badly needed wake-up call for the EPA which has neglected a program that deserved far more funding for decades, and our air quality has paid a price. As fossil fuel prices climb, wood heaters are getting more popular and sales have increased dramatically in recent years. Many policies and strategies are needed to reform and guide this renewable energy pathway beyond the deficiencies of the EPA’s certification program. It’s important for all stakeholders to look at the bigger picture and not be constricted by the narrative that emerged from the NESCAUM report.

    One line in the OIG report elicited ridicule from the wood heating community.  It said, “regulators and the public do not have reasonable assurance that certified wood heaters meet emission standards under real-world conditions,” (OIG 2023, 19). We can only assume that the authors of the OIG report knew that EPA emission standards were never meant to mimic real-world conditions and regulators know that all too well. For many in the wood stove industry, this statement undercut the credibility of the report.

    One weakness in the OIG report is its perfunctory treatment of the connection between Wood Smoke and Environmental Justice (EJ). The OIG did not refer to the findings in the 2015 New Source Performance Standards (NSPS), that “risks due to residential wood smoke emissions for disadvantaged population groups generally are lower than the risks for the general population due to residential wood smoke emissions,” (EPA 2010, 9). The 2015 NSPS predated the level of attention that the EPA is now supposed to give to EJ issues, but still EPA has never treated wood smoke as a serious EJ issue. The EPA relied on a very narrow 2010 study commissioned by the EPA’s Gil Wood that did not find increased cancer rate in census data that tracks with higher rates of wood smoke. A finding that wood smoke did disproportionately impact disadvantaged groups would have triggered a requirement that the EPA would have to spend resources to further study this issue. The NSPS discussed the potential causal relationship between wood smoke and cancer numerous times, but when it came to disadvantaged groups, the 2015 NSPS said:

“This proposed rule [2015 NSPS] is not subject to Executive Order 13045 (62 FR 19885, April

23, 1997) because the agency does not believe the environmental health risks or safety risks addressed by this action present a disproportionate risk to children. The report, “Analysis of Exposure to Residential Wood Combustion Emissions for Different Socio-Economic Groups,” shows that on a nationwide basis, cancer risks due to residential wood smoke emissions among disadvantaged population groups generally are lower than the risks for the general population due to residential wood smoke emissions,” (NSPS 2015, 13700). 

    AGH believes this statement is not sufficiently supported by data and reflects the interests of an NSPS process that lacked the funding and leadership to address the EJ issues that wood smoke presents for rural impoverished and marginalized communities. The OIG report did little to change this trajectory. AGH, tribes and firewood banks are urging the EPA to use EJ funds to help wood heating communities.

AGH perspectives on some of the findings of the OIG report.  Sentences in quotes are from the OIG report, followed by AGH’s commentary.

“The EPA Does Not Have an Effective Program for Testing and Certifying Wood Heaters,” (OIG 2023, 13).   

    AGH largely agrees with this basic conclusion that underlies the OIG report. Despite all the shortcomings of the EPA, which were only made widely public by NESCAUM and the Alaska Department of Environmental Conservation (ADEC), it's important to also remember that the EPA program is likely the best certification and testing program in the world for cord wood stoves, and it has pushed manufacturers to build stoves that are cleaner than anywhere else in the world. Testing of solid fuel heaters is inherently extremely complex, rendering programs to regulate them vulnerable.  

“The 2015 NSPS and Certification Test Methods Are Flawed,” (OIG 2023, 13). 

    AGH agrees that the 2015 NSPS is flawed but we should not forget some of its most important and most successful results. It finally made outdoor boilers a fully regulated appliance, and ended the loophole of allowing many wood and pellet stoves to be “exempt.” It also jump started a new category of stoves: hybrid stoves that use both catalytic and non-catalytic smoke reduction technologies. However, the operational benefits of hybrid stoves have been overlooked by ADEC and NESCAUM, contributing to California Air Resources Board (CARB) focusing on catalytic stoves in their change-out programs instead of hybrid stoves, which continue to reduce PM even if the cat is not engaged or its clogged or missing.  OECA has also made many improvements to its database of certified wood heaters. The database used to be maintained on excel spreadsheets and lacked much of the detail that it now has. We hope it will be further populated with relevant info, including the expiration date of each stove’s certificate in ways that will not confuse consumers. The EPA program is effective and credible in many ways, despite the deep flaws identified in the OIG’s report. 

• The 1988 NSPS was far more flawed than the 2015 NSPS and for 20 years the EPA largely ignored those flaws, as did state agencies.  

• ALT-125 and ALT-127 (ASTM E3053) could have been improved, instead of revoked.  

• “Testing labs can conduct test runs to produce data that misrepresent wood heater performance to regulators and consumers,” (OIG 2023, 14). This has always been the case and is not a product of the 2015 NSPS.

“The Wood Heater Certificate-of-Compliance Process Lacks Internal Controls,”(OIG 2023, 19). 

    AGH agrees with this conclusion and OECA’s estimate of $100,000 to continue detailed review of certification papers is a small sum given the improvements needed. We question whether the use of contractors is the best way forward for OECA, rather than building its own internal capacity and expertise.   

• “The Agency Does Not Exercise Its Authority to Observe Certification Testing,” (OIG 2023, 21). This activity is yet another victim of underfunding. We believe both OECA and the Office of Air Quality Planning and Standards (OAQPS) staff should regularly observe certification testing as a primary strategy to build its expertise. 

• “The EPA Does Not Use Its Regulatory Authority to Conduct Compliance Audit Tests,” (OIG 2023, 21). We urge the EPA to begin compliance audit testing, primarily of the most popular models to start with

OIG RECOMMENDATIONS

• “Develop and implement a plan to demonstrate whether residential wood heaters certified using the test methods based on ASTM E3053 comply with the New Source Performance Standards for residential wood heaters,” (OIG 2023, 26). This is a nonsensical recommendation unless similar tests are done on stoves tested with Method 28. The EPA should approach all test methods without bias and develop scientific ways to assess all test methods.  

• “Develop and adopt an EPA cord wood test method that is supported by data to provide the public reasonable assurance that certified appliances meet emission standards,” (OIG 2023, 26). Emission numbers in labs will never be the same as emissions in the hands of consumers, particularly if manually operated stoves continue as the dominant technology in North America.  Automated stoves and controls like ESPs are likely the leading options to reduce the gap between lab and field emission profiles. 

• “Establish mechanisms to promote independence between emissions testing labs and third-party certifiers,” (OIG 2023, 26). AGH is not convinced that the next NSPS should extend the role of third-party certifiers. While it may have been a good idea, it didn’t work and other strategies should be considered before trying to fix this process.

Response of the EPA

    We believe that it's important to also read the response by the EPA to the OIG which was included in the end of the report.  We felt their response was fair and measured, and acknowledged many of the charges in the OIG report. However, the EPA also pushed back in many areas, such as this: “The OIG draft report improperly conveys that EPA has generally not altered how we are implementing the wood heater program,”(OIG 2023, 30). We fully agree with this statement because the EPA began improving their program even before the NESCAUM report came out, and accelerated their pace afterwards.  

Conclusion

    AGH believes the work of ADEC, NESCAUM and the EPA’s OIG is generally having a positive impact.  While there have been many missteps and miscommunication, and sometimes an inordinate burden on manufacturers, this process finally got the attention of the EPA leadership and more resources to the EPA offices working on these important issues. It is still unclear if the EPA leadership will continue to give more priority and more resources to this area in coming years and under different administrations.

    States also have a responsibility to put more resources into this area and develop their expertise, if they want to see continued change at the federal level. States can do a lot, as Washington and Oregon have demonstrated by banning the installation of uncertified stove. Cities can restrict the installation of any wood stove and other solutions are emerging in Europe such as requiring electrostatic precipitators, whose prices are dropping rapidly. The Department of Energy (DOE), their national labs and universities can also play a vital role by supporting more R&D and pushing for the development of automated, computer generated stoves, something the EPA has paid little attention to.

    Wood and pellet stoves are not going away and provide a vital source of renewable heat to more than 10 million American homes. They have successfully helped America decarbonize residential heating far more than they get credit for. With increased R&D, innovation and regulatory oversight, wood and pellet heat can continue to help us achieve carbon reductions that are badly needed to stave off the worst impacts of global climate change. A key part of this process lies with the EPA by addressing many of the issues raised in the OIG report.