EPA announces extraordinary overhaul of wood stove certification program

Confidence in wood stove testing program shaken in wake of Alaska and NESCAUM exposé

Richard Wayland leads the nation’s
technical air quality management
programs

On Tuesday, April 5, the EPA published letters that they sent to wood stove testing labs, announcing they were embarking on a historic review of certification paperwork, similar to the examination that the state of Alaska is conducting.

 

The publication of the letters may have been prompted by a freedom of information request from a reporter, who got access to the letters hours before the EPA published them.

 

The overhaul could end up costing stove manufacturers large sums of money and the revocation of some models' certification.  This is sending reverberations throughout the manufacturing community of wood and pellet heating appliances, which has never faced such scrutiny and oversight since wood stoves were first required to be certified in 1988.

 

The EPA announcement is also derailing, at least temporarily, a move by members of Congress to refile legislation that would establish a national wood stove change out program heralded by industry as the best way to combat excessive wood smoke.  The EPA emphasized that local and state change out programs rely on EPA certification documents to help determine which stoves can achieve the best emission reductions. 

 

The immediate actions by the EPA include using a template similar to the one used by the state of Alaska to see if their review of deficiencies in paperwork matches the the state's review.  This indicates, as early reports confirm, that the EPA may not agree with some of the categories of deficiencies Alaska thought were significant.

 

The EPA is also announcing that starting immediately, they will be conducting far more intensive reviews of new certifications.  This is believed to also include the routine retesting waivers.  Under the current system, once a stove gets certified, it receives a 5-year certificate that can be renewed, without any additional testing, over and over.  While this benefits manufacturers who, prior to 2015, were still marketing stoves certified in the 1990s, it did not incentivize making even small improvements in the cleanliness or efficiency of the unit every 5 years.  

 

The letters to the EPA approved stove testing labs also put the labs under notice that they could lose their approved status if they do not improve their standard operating procedures. It is unclear why half of EPA approved labs and third-party certifiers appear to have expired approvals.  The newest third-party certifier, Guardian Fire Testing Laboratories, is based in New York, the state that has been providing most of the funding to NESCAUM through its energy department, NYSERDA.

List of EPA approved labs and 3rd
party certifiers who received letters

 

Although the letters the EPA sent to wood stove test labs dealt mostly with enforcement issues, they did not come from the EPA's Office of Enforcement, but rather from Richard Wayland, the Director of the Air Quality Assessment Division, which typically does not handle such measures.  Wayland’s Division is now under a new high profile political appointee, Joseph Goffman, who was one of Biden's top advisors during the presidential transition.  Under Goffman is Tomas Carbonell, the Deputy Assistant Administrator for Stationary Sources, another political appointee who worked on the 2015 wood heater NSPS during his tenure at the Environmental Defense Fund.  This may indicate a shifting and larger role for senior leadership at the Office of Air and Radiation, a potential sign that the Biden Administration is taking the NESCAUM report very seriously.

 

The EPA stopped short of implementing some of the recommendations in the NESCAUM report.  For instance, they have not yet indicated any interest in revoking an ASTM cordwood test method that NESCAUM and Alaska found to be flawed.  However, the agency did emphasize that the recently approved IDC cordwood test method could be used by any manufacturer and updated their approval of the method, possibly to correct an error found by veteran stove tester Ben Myren.  That error, which the Alliance for Green Heat highlighted in a recent blog, dealt with the amount of bark that must be left on logs during certification testing, and highlights the precarious role of the EPA in approving test methods where the underlying data has not been publicly released for experts to review.  It is unclear if EPA even had access to the IDC test method's underlying data which is owned by NYSERDA.  If the agency does have the data, it could make it available or it may have to disclose it through freedom of information requests.  

The EPA's announcement of this major overhaul comes just days after many top stove manufacturers and the main industry association, the Hearth, Patio & Barbecue Association,  filed comments vigorously opposing the results of the Alaska stove certification review. If the EPA does not approve Alaska's scheme of culling out stoves with too many deficiencies in their paperwork and which emit more than 6 grams an out during test runs, Alaska may be forced to only allow the new installation of pellet appliances in the Fairbanks area, that is fighting federal non-attainment status.

For many years, experts have known of the mounting complexities and loopholes in testing wood stoves. Then, by 2020, it became apparent that many stoves that were tested above 2 grams an hour were somehow able to test to below 2 grams an hour without being altered, calling into question whether the regulations led to a cleaner generation of wood stoves.  Pellet stoves and boilers however have genuinely become cleaner and more efficient from the tighter 2020 emission standards because of their automated functions and consistent fuel qualities. 

Related stories

EPA's cordwood test protocol moves forward (July 2021)

EPA and states vigorously defend stove audits (Sept. 2020)

Opinions of top stove industry insiders on controversial topics (Aug. 2017)

Study shows environmental advantages of pellet stoves and exaggerations by manufacturers (Oct. 2015)

 

Veteran lab technician challenges Alaska's wood stove criteria

Ben Myren, left, with Larry Brockman
at the 2018 Stove Design Challenge
where the IDC was showcased.

Updated, April 2, 2021 - Ben Myren, one of the nation's most experienced wood stove test lab experts, is frustrated with the officials in Alaska that are trying to enact stricter wood stove standards.  Fairbanks has to design a State Implementation Plan (SIP), to clean up their air to meet federal air quality limits or face sanctions. 

Myren is not alone in his opposition to the way Alaska is seeking to crack down on more polluting stoves.  Nineteen entities responded to the EPA's public comment on the Alaska stove requirements and all 19 were very negative.  This is not entirely surprising considering all 19 comments came from the wood stove industry, mainly from manufacturers.  Their comments can be viewed here and Myren's comments are reproduced below.  Companies that commented against the ADEC proposal included HHT, US Stove, Jotul, Rais, Blaze King, Central Boiler and Woodstock Soapstone.

The Alaska Department of Environmental Conservation (ADEC) stove requirements resulted from  a novel and ambitious review of certification reports of all wood stoves. According to its reports, the agency found missing and flawed data in nearly every set of certification papers sent to the EPA by EPA approved testing labs. One of those labs, run by Ben Myren, provided scores of reports ADEC found to be deficient.

Following ADEC's review, the Northeast States for Coordinated Air Use Management (NESCAUM), a non-profit based in Boston, used that data in a scathing report that found the EPA's system of certifying wood and pellet stoves boilers and furnaces to be "dysfunctional." Currently, high level officials at the EPA are reviewing the NESCAUM report and the stove industry and states are waiting to see what parts of the report the EPA will address and how. In the meantime, the EPA has reportedly stopped processing certification paperwork.

The stove industry association, the Hearth, Patio & Barbecue Association (HPBA) dismissed the NESCAUM report in a blog by John Crouch, their Director of Public Affairs, saying they do not see "any indication that the regulatory process doesn't work." Instead, Crouch says that the report is the result of an "anti-woodstove agenda" and its authors are trying to "find a problem so that they can push for their desired outcome." The Alliance for Green Heat's response urged the EPA to "take the report seriously", and calls on the Biden Administration to provide more resources for implementation and enforcement. AGH was critical that the report failed to sufficiently distinguish the far more fair and reliable testing of pellet stoves and boilers, which could undermine important efforts of New England states to incentivize modern pellet heating as a means of reducing fossil fuel reliance.

Myren, and most of the manufacturers who commented objected to virtually all the keys ways Alaska is trying to require stricter standards in their effort to convince the EPA that they are addressing its air pollution non-attainment problem. The EPA accepted Missoula's strategy of simply banning new installations of wood stoves and limiting pellet stove installs to devices emitting 1.0 g/h or less. Missoula's 1.0 g/h limit was also enacted ex post facto, and did not give manufacturers the chance to meet the stricter local standard in advance. Myren notes that Alaska's requirement that stoves not emit more than 6 g/h during the first hour of a test to be sold in Fairbanks is unfair, including because some stoves test with a cold start and capture heavy start-up emissions while others test from a hot start. 

ADEC points out that the strong objections posed in all the industry comments may backfire, because if the EPA rejects ADEC's approach, the fallback may be simply ban the installation of new cord wood stoves, like Missoula did.  The EPA approved Missoula's strategy and ADEC is using that as a yardstick to craft something that may be equally effective at reducing wood smoke, but still allow Fairbanks residents to install more cordwood stoves. 

Myren also found that ADEC appears to be requiring more bark on the test loads of cordwood for the ASTM test than for the Integrated Duty Cycle (IDC) test it asked the EPA to approve. Thus, if a lab uses the IDC method to certify a stove, it may fail ADEC's criteria. If Fairbanks wants a test method that will help identify stoves that will perform well in that polar-like environment, Myren argues that the IDC fails on many counts. In fact, Fairbanks may do better to alter the IDC to test stoves for their ability to burn in sub-zero temperatures, which causes a much higher draft than used in the IDC.

 

MYREN CONSULTING, INC.

AIR PLAN APPROVAL; AK, FAIRBANKS NORTH STAR BOROUGH;

2006 24-HOUR PM_2.5 SERIOUS AREA PLAN

86 FED. REG. 10,511 (FEB.22, 2021)

 

     The US EPA is proposing to approve parts of the Alaska State Implementation Plan for the Fairbanks North Star Borough Area (NSSIP).  Part of the NSSIP includes revised emissions standards and, possibly new test methods, for wood stoves.  Myren Consulting, Inc. (MCI) would like to offer the following comments on these proposed actions.

 

     1. EPA’s initial choice of the 2.5 g/h particulate emissions (PM) standard for wood stoves tested with cord wood (the cord wood option, see Section 60.532(c) in the 2015 NSPS) was made without any supporting data that demonstrated that the 2.5 g/h standard related in any way to the crib fuel standard of 2.0 g/h.  (See Section 60.532(b) in the 2015 NSPS.)  In short, EPA never conducted any M301 Validation tests to compare the emissions from the 2 different test methods (EPA M28/ M28R and ASTM E3053) used to determine PM emissions from wood stoves.  Thus, any use of the 2.5 g/h standard in the deliberations that led to the content in the NSSIP is both arbitrary and capricious.

 

            2. The Alaska Department of Environmental Conservation’s (ADEC) choice of a 6.0 g/h PM emission limit has also been made without any similar supporting data.  Thus it is also arbitrary and capricious.  

 

3. The 6.0 g/h PM emission limit is also arbitrary and capricious because it does not differentiate between the two test methods, EPA M28/ M28R and ASTM E3053, presently being used to certify wood stoves.  The operating and fueling protocols in these two test methods are very, very different.  The EPA M28/ M28R requires hot to hot tests for all tests with the crib fuel loads made from dimensional lumber (2x4’s and 4X4’s) that uses a loading density of 7 lbs. ±10%.  ASTM E3053 requires a cold to hot start for the High burn, hot to hot starts for the Medium and Low burns.  The fuel used in ASTM E3053 is cord wood with a loading density of 10 lbs. ±5% for the High burn and 12 lbs. ±5% for the Medium and Low burns.  Just the difference in fuel type (crib fuel vs. cordwood) and loading densities (7 lbs. ±10% vs. 10 lbs. ±5%/ 12 lbs. ±5%) would suggest that the 6.0 g/h limit can not be applied evenly to these two methods. 

 

4. Given the way the stoves burn during these tests, especially for the ASTM E3053 cold start High burn, the 60 minute filter pull 

happens at very different times in terms of what is taking place in the firebox.  On smaller stoves being tested with ASTM E3053, it is very possible that the filter changed at 60 minutes will contain all of the emissions from the cold start (K/S) phase plus a portion, the dirtiest portion that includes coal bed leveling, loading and ignition of the High burn fuel load.  Here again, the failure to differentiate between what is happening in the firebox on stoves of different sizes renders the 6.0 g/h unfair and arbitrary and capricious.

 

5. The same is true for the larger fuel loads required in the ASTM E3053 tests, i.e., higher loading densities means larger/heavier fuel loads, which take longer to ignite, so the emissions will understandably be higher during the first 60 minutes.  Again no differentiation, which is unfair, arbitrary and capricious.

 

     6. The 6.0 g/h 60 minute PM emission limit is being applied in an ex post facto manner.  Had manufacturer’s known about this limit in advance, they would have had the opportunity to change their wood stove designs and bring their stoves into compliance.  However, that is not the case with the presently proposed rules because the 6.0 g/h rule is being applied to stoves already certified.  That, again, is grossly unfair, not to mention arbitrary and capricious.  

 

     7. The ADEC’s certification stove review process is horribly skewed, because it requires documents that were never previously required in the EPA certification process.  Here I am referring to the newly required documents titled “Document of Run Appropriateness”, “Document of Run Validity”, “Document of Run Anomalies” and “Document of Run Burn Rates”.  These documents are nothing more than “boilerplate” and do nothing to effect the actual test results.  Again, this is grossly unfair, not to mention arbitrary and capricious. 

 

8. In addition, the ADEC review criteria often establishes other new criteria that, in effect, establish new more stringent criteria that must be met before a stove can obtain ADEC approval.  One of these is the establishment of an undefined requirement for the medium dry burn rate for cord wood stoves.  The question asked in the ADEC’s Summary of Review” in the “Comments” section is essentially, “Why is this Medium primary air control setting representative of what is needed for a Medium burn?”  Yet the data presented show that the dry burn rate in the test report meets the requirement set forth in the test method.  Thus, the ADEC is revising test criteria after the fact.  Again this is grossly unfair, not to mention arbitrary and capricious. 

 

9. Similarly, the ADEC’s Summary of Review for wood stoves certified with cord wood using ASTM E3053 seems have a minimum requirement that at least 50% of one side of each fuel piece be covered with bark.  Yet that 50% requirement clearly contradicts what is found Section 3.29 in the recently approved Integrated Duty Cycle (IDC) test method (EPA Alternate Test Method ALT-140) which states in part:

 

“…Test fuel charge – the collection of test fuel pieces used in   each of the four phases of the test run.  L2, L3, and L4 require that at least 5% of the individual pieces with at least 80% bark on one side of the fuel piece…”  

 

 ASTM E3053 Section 8.4.2.1 states that

 

“…Only cordwood pieces that are free of decay, fungus and

loose bark shall be used…” 

 

Thus there is no “official” bark requirement in the ASTM standard.

 

However, in as much as the ADEC requested approval of the AK version of the IDC contains the above cited bark requirement, it seems hard to believe that the ADEC would require an even more stringent bark requirement for stoves tested with the ASTM test method than is required in the IDC test method the ADEC requested EPA approve.  Or is this, once again, just one more instance of an unfair, arbitrary and capricious decision making process.

 

10. The IDC test method as presently written (Version V7B_2.23.2021 AK IDC) and recently approved by EPA as ALT-140 can not be used as it is written.  Thus any mention of the above cited document in the entire NSSIP document as a means to improve air quality in the North Star Borough is unwarranted.  You can’t cite what you can’t use.  And any use of data generated via testing with the above version of the IDC, or any unapproved version of the IDC for that matter is also invalid, because the test method can’t be used as written.

 

11. Despite claims to the contrary, the IDC test method does not in any way reflect a real world operating scenario.  This is especially true of the Fairbanks North Borough where typical winter subzero temperatures would find homeowners operating their stove with the primary air control (PAC) wide open, not closed to the minimum primary air setting as is required for well over half of the IDC test, i.e., in the IDC test the PAC is set at wide open for the cold start portion of the test and the first 50% of the High burn fuel load weight.  After 50% of the High burn fuel load has been burnt, the PAC must be set to the minimum air setting for the rest of the High burn and all of the Maintenance fire phase, i.e., no additional air is allowed when the Maintenance fire fuel load is loaded into the stove.  The PAC stays at the minimum air setting until the start of the Overnight fire phase, when the PAC can be opened to the maximum setting for the first 10 minutes of a test and then the  PAC must be returned to the minimum air setting and must stay at that setting for the rest of the test.  Does that sound like a typical operating scenario for a stove in the North Star Borough when the outside temperature is less than 10-20 degrees F? 

 

10. If one looks at the entire US in terms of wood burning, Fairbanks is an “outlier” due to the extreme temperatures that occur there.  Thus, the solutions for resolving the air quality issues for Fairbanks may have little or no relevance to resolving air quality issues elsewhere in the US.  EPA needs to recognize this “outlier” status if it should chose to approve any of the suggested proposals to reduce the PM emissions form wood stoves in the Fairbanks area. 

 

11. And lastly, no matter which of the present test methods, i.e., EPA M28/ M28R, ASTM E3053 or the AK IDC, one would decide to use, the stoves certified via that test method will not work well in the field because of the difference in the draft (static pressure (pg)) generated by a freely communicated lab chimney versus the draft that is generated by a real world chimney that vents into the outside air.  Here research has shown that the draft generated by a 28 foot chimney vented into outside air that is 10F can double the dry burn rate of a stove.  Imagine what would happen to the dry burn rate and stove emissions when the outside temperature is -40F.  The Europeans have long recognized this problem and so have induced a draft (12-14 Pa) during their emission testing.  Now they are working on a new test method where the draft is varied over the course of a test run, with the variation in induced draft being determined by 4 different variables, chimney height, outside ambient temperature, flue gas temperature and flue gas static pressure.  Again, failure to recognize the problems with existing test methods and try to eliminate one or more in favor a perceived “better” method ignores reality.  Especially when no actual field testing ahs been done to validate these assumptions, which renders any preference for a particular test method arbitrary and capricious.  

 

In conclusion, many of the criteria the ADEC wished EPA to approve are not based upon scientific data and facts, but instead are simply an arbitrary and capricious choice. 

 

Thank you for the opportunity to present this testimony.

 

Ben Myren, President

Myren Consulting, Inc.

512 Williams Lake Road

Colville, WA 99114

email: <myren.ben@gmail.com>

Related stories

Alaska releases deficiency details on wood and pellet stove test reports (Nov. 2020)

AGH response to NESCAUM report on data from Alaska process (March 2021)

Alaska building list of cleaner, properly certified wood and pellet stoves (Oct. 2020)

Records reveal successes and challenges in laboratory wood heater testing

Stove and boiler regulations appear to have survived Trump’s first term 

As the wood stove industry nears the May 15, 2020 deadline for meeting stricter emission standards, EPA records show a steady stream of stoves being certified but do not show which models, if any, failed. Manufacturers are required to notify the EPA of stoves they are testing 30 days in advance of the test and to report results after 60 days. Labs are also required to provide emission data to the EPA within 60 days, even if a test is suspended.

Percent of certification tests
scheduled for larger EPA-
approved test labs.  

Data from stove certification tests is a core resource for understanding and improving the effectiveness of regulations. A trove of documents just became available that helps us better understand how stove testing works and how a declining number of EPA staff is trying to oversee detailed regulations that partially rely on an honor system within the industry they are regulating.

Data recently released by EPA shows the pipeline of what is being tested by which lab, what has not been certified and other trends. The 2015 performance standards for residential wood heaters require manufacturers to notify the EPA at least 30 days in advance of the model’s certification test in an EPA-approved laboratory.

The EPA does not maintain a public database of 30-day notices, but the Northeastern interstate air quality organization NESCAUM requested copies of these reports through the Freedom of Information Act (FOIA). The main function of the 30-day notice is to enable the EPA and other agencies to witness testing, which otherwise occurs behind closed doors.

There is nothing proprietary in the 30-day notices and the EPA has no grounds to keep them confidential. Once anyone files a FOIA, the information is made public on the US government FOIA online site. To find the underlying data from these requests, type in “NESCAUM” in the FOIA online site or use these record locators: EPA-HQ-2019-006560, EPA-HQ-2019-000324 and EPA-HQ-2018-006770.

The EPA provided 30-day notices filed between 2015 and 2019 for 143 distinct heaters and 41 duplicate notices.  Matching the 30-day notices to the end result on the EPA's certified heater database indicates that approximately two-thirds of them are certified to 2020 standards.

We could not tell, for example, if crib tested stoves had a higher or lower passage rate then cordwood tested stoves, or which fuel led to more suspensions. The rapid rise in popularity of the cordwood test may indicate the stove manufacturer community’s confidence that they will not be more likely to suspend or fail a test.

More than 10 stoves or central heaters may have been certified since 2015 but only achieved Step 1 standards. The reason for this is unclear. It could be that these stoves already had Step 1 status but failed to achieve Step 2 emission limits. It may also indicate that manufacturers thought the EPA regulations would be struck down or EPA would grant a sell-through, neither of which appear to be happening at this point.

The EPA’s inaction to date on revising  2015 NSPS, and HPBA's strategy to seek repeated delays in their litigation, means that Step 1 stoves will likely be illegal to sell in the US after May 15, 2020. For companies that certified to Step 1 standards since May 2015, the expenses of testing the stove, and potentially modifying it, resulted in a stove that can only be sold for 2 – 4 years on the US market.

Approximately twenty-three stoves with 30-day notices do not appear on the EPA database of certified heaters. It is possible that some of the unlisted stoves have been tested very recently and are still in the certification process, while others might have failed certification testing, did not make it to market for a separate reason, or were discontinued by the manufacturer. 

Test labs

Two labs, Polytest and Omni, test a majority of stoves for the American market. Polytest is based in Montreal and Omni in Portland, Oregon. PFS acquired Dirigo, so it is now one lab, also based in Portland Oregon. Dirigo used to qualify or certify many outdoor wood boilers. Myren Labs is now only an R&D shop and no longer conducts certification tests, but EPA-approved labs can certify at Myren's lab. Two relatively new European EPA labs – RISE (formally SP) in Sweden and the Danish Technology Institute (DTI) have done a few certification tests.  Only the SZU lab in Czech Republic has apparently not yet done certification testing for any heaters for the US.

Four labs account for the great
majority of certification testing.

Polytest and Omni are also the labs that certify the most stoves with the ASTM cordwood protocol, though all labs now have experience with cordwood for either stoves or boilers.

Many stoves certification tests are done in manufacturers’ or R&D labs by EPA-approved lab technicians who travel there to undertake the testing. Using the same lab that the stove was developed in may be one way to enhance the repeatability of emissions testing and help ensure the stoves passes.

Stoves vs. boilers, crib vs. cordwood

Currently, there are 130 appliances on the EPA's central heater database, however we only have 14 30-day notices in for central heaters (boilers and furnaces), indicating a drastic cut back on testing central heaters to 2020 standards since 2015. Moreover, the testing of those units only resulted in 3 certified heaters: 2 European pellet boilers and 1 domestic cordwood furnace. Possibly the most notable manufacturer that does not have a 2020 certified unit is Central Boiler, who led the charge to stave off the EPA’s 2020 emission standards (litigation still outstanding). Omni labs filed a notice to test a new Central Boiler unit in the winter of 2017, but as this unit does not appear on the EPA list, it is unclear if the testing was suspended or what the results were.

The majority of the 30-day notices obtained were for stoves or room heaters, a category which includes wood, pellet, and multi-fuel stoves. Of these 129 unique room heaters, 36% listed crib wood, 33% pellets, 25% cord wood, and 2% coal/wood and >1% densified logs as the test fuel on the notice. A few 30-day notices did not have a fuel type selected. Twenty-two heaters were listed as having a catalyst, and at least five stoves were single burn rate stoves, a feature that is sometimes not advertised to consumers.

Posting non-confidential lab reports

A new provision of the 2015 EPA stove regulations requires manufacturers to publish their certification testing reports. These lab reports include all emission data, efficiency, grams per hour for each test run and the averaged final numbers. They also include photos of the stove and the crib loads, how the stove was loaded and other data once routinely kept private by manufacturers. These lab reports are usually too technical for the average consumer, but often read by other manufacturers, regulators, retailers and stove hobbyists.

However, these reports are sometimes hard to find on company websites and sometimes appear not to be posted at all by a few smaller manufacturers. After extensive searching, AGH was able to find more than 90% of the 2020 certified heaters’ certification reports online, as well as most Step 1 reports. To be listed as a certified heater by the EPA, manufacturers must provide the EPA with a link to their online report.  While major manufacturers are posting their reports, some remain hidden or difficult to find. And, since most stoves were grandfathered into the 2015 Step emission category, many lab reports detail the original certification testing which happened 15 – 30 years ago. (Once a stove was certified, it received a 5-year certificate of certification, which could be renewed without any additional testing every five years. Some currently certified stoves models are using tests conducting in the early 1990s, having received 5 EPA renewal approvals.)

Lab reports are often more than 200 pages long, but some companies limit what they disclose. Some are only 20 pages, and black out things such as the name of the company representative who witnessed the test. One very old report, from 1992, was only 2 pages long. Manufacturers are only required to post test reports for units tested after 2015, but the overwhelming majority posted test reports for all their certified units, providing testing transparency for the first time and access to third-party efficiency data, which consumers did not have access to before.  A few companies, including Central Boiler, only make reports public for tests done after 2015 and not for all of its certified units. (Those tests reports could likely be obtained through a FOIA request.)

Most companies maintain a single, centralized page for all their lab reports, making it easy to find them with a single click. They are called a variety for names from test report, to EPA data to website report, to certification certificate. Innovative Hearth Products that owns Astria, Ironstrike and Superior have some of the hardest pages to find as they are simply titled “Wood Heaters” and tech support told us that the company did not post those reports. Other manufacturers have the lab test report on the individual product page. At least 4 companies fixed broken links and reposted their test reports after we contacted them, notifying them that we could not locate them.

Links to non-CBI test lab reports

This is not an exhaustive list of manufacturers but includes most of the larger stove companies. (We will periodically update these links.)

Lab reports on central page: 509 Fabrications, Arada Stoves, Astria, Blaze King, Buck Stoves, Central Boiler, Drolet, Enerzone, Enerco Group (Mr. Heater), England's Stove Works, Enviro, Fire Chief Industries, Foyers Supreme, FPI Regency, Harman, Hearthstone, Iron Strike, JA Roby, Kuma, Morso, Napoleon, Osburn, Pacific Energy, Quadrafire, Regency, STUV, Superior, Travis/Lopi, US Stove, Vermont Castings, Woodstock Soapstone.

Lab reports on individual product pages: Froling, Jotul, MF Fire, RSF, Sierra Products, Thelin, Thermorossi, Timberwolf, Wittus (links go to a sample report).

Lab reports not found: Invicta, Laminox (we sent multiple emails and will post links if we get responses.)

Suspension of certification tests

From a review of 30-day notices of lab tests, and resulting certification, it would appear that virtually no stove fails a certification test. That is because if initial test runs are not going well, the certification test is suspended. There is no point continuing costly tests if the average grams per hour for all the tests is not going to be below 2 or 2.5 grams an hour. However, the EPA’s 2015 stove heater regulators require labs to “agree to immediately notify the Administrator of any suspended tests through email and in writing, giving the date suspended, the reason(s) why, and the projected date for restarting. The laboratory must submit the operation and test data obtained, even if the test is not completed.”

This data enables the EPA, state regulators and industry experts to understand how rigorous – or easy – a test protocol is for stoves of various firebox sizes and designs depending on whether crib or cordwood is used, for example.

In addition, the 2015 wood heater regulations stipulates, “Within 60 days after the date of completing each performance test, e.g., initial certification test, tests conducted for quality assurance, and tests for renewal or recertification, each manufacturer must submit the performance test data” to the EPA. Thus whether the tests resulted in certification, or were suspended or failed, the data still goes to the EPA and becomes part of the public record.

However, most labs appear to not always comply with this part of the NSPS and the EPA appears to not be strictly enforcing compliance (NESCAUM as submitted a FOIA request (EPA-HQ-2019-008306) for suspended test reports). This undermines the process of developing better test methods that could result in genuinely cleaner stoves.  In an unusual move, the EPA made a memo to test labs public that detailed lapses in lab test reports.  Filing reports from suspended tests was not among the issues the EPA raised to labs.

The high certification success rate of stoves scheduled to be tested may appear to undermine industry claims that the 2020 standards are impossible or crippling. However, stoves are intensively tested in private or internal labs before they are scheduled for expensive certification testing, as manufacturers need to know that they have a high chance of success to justify the expense. Manufacturers need to be able to repeat the prescribed test protocol relatively consistently to avoid a level of randomness between practice tests and certification tests that could result in repeatedly suspending certification tests. This issue of repeatability is at the core of the entire concept that wood heater testing is a valid and useful way to tell which heater is clean enough to put into homes and communities across America.

The fact that a very high percentage of certification tests are successful may undermine some industry claims that the variability of testing stoves under 2 grams an hour is far too high to render the test useful. Manufacturers have reams of data from in-house testing that could show how close their certification test results were to their practice tests. Some communities, often outside of the HPBA core, are far more transparent in sharing testing data, such as the Masonry Heater Association and various parts of the international cook stove community.

It is unclear if all manufacturers are following the same guidance about filing 30-day notices, as the EPA has become laxer about when wood heaters can be tested. Heaters often face delays in testing due to a variety of reasons, technically requiring a new 30-day notice. One stove AGH found has seven 30-days notices filed for it. Others had only one, but they may have delayed the test multiple times.

Conflicts of interest

An equally thorny issue is the conflict-ridden economic relationship between the labs and manufacturers. Labs want their clients to have confidence that they can get their stoves or boilers to pass the certification test. There is a process leading up to a certification test where labs come to know the strengths and weaknesses of a heater and match those with the areas of flexibility in a test protocol.

Labs guard their privacy and confidentiality on behalf of their clients. Curtains are often used to ensure that visitors cannot see whose heaters are being tested, and when and how. The 30-day notification rule was supposed to enable state or federal regulators to periodically witness certification - announced or unannounced. Witnessing testing allows regulators to understand the complexities, nuances and loopholes involved. Without that understanding, regulators cannot gain the level of expertise necessary to enforce existing rules, much less write better ones.

But here is the rub: AGH is not aware of any federal or state regulator who has witnessed a certification test in the last 5 years.  Rod Tinnemore, a Washington State regulator was one of the few who did witness tests and he gained the expertise, trust and respect of many stakeholders.  After his retirement, Washington appears to have backed off its multifaceted wood heater roles. Certification tests often last 4 – 7 days and can be very boring. Labs exist in only a few states and agencies do not have the time, resources – and sometimes even the authority – to witness testing. Most regulators do not even have the expertise to fully understand what they are witnessing and what nuanced lab practices are allowed or not allowed. The result is nearly a classic catch-22.

Conflicts are also potentially abundant in stove testing protocols like the ASTM E3053-17, which was developed and paid for by many of the same industry players whose stoves will be certified by those methods. Developing a protocol is an expensive and lengthy process, and there is no guarantee that it will be approved for use by the EPA and the EPA can unilaterally modify its use for certification testing. The EPA, however, may not have the resources and data to fully understand the nuances of a new alternative protocol until years later, when enough stoves have used the method. Further handicapping their oversight role is not consistently getting data from manufacturers for suspended tests.

Ultimately, audit testing of stoves in the same and different labs that certification testing was performing will likely be needed to bring attention and clarity that many of these issues deserve.  Audit testing by the EPA and/or states may help all labs ensure that testing parameters are consistently applied.

Similar, but more entrenched conflicts of interest in the European community stove testing community have led to what many experts regard as weak and ineffectual testing regimes. Some fear a convergence of cultures in US and European test labs if the EPA loses more staff and resources, or has its hands tied by appointed officials who favor industry concerns.

Future Challenges

Corporate, religious and educational institutions across America are coming to terms with legacies where people felt they had conflicts of interest and didn’t speak up about infractions and abuses. The VW auto testing scandal is a perfect example because it was in plain sight all along but everyone involved kept quiet. The issues and the stakes appear to be far smaller in the wood heater community, but we are dealing with devices that combust at extraordinarily hot temperatures in our living rooms and basements. When those temperatures are not present, the chimney may be emitting excessive particulates into our neighborhoods. Like the European auto testing community, the wood heater industry is also a relatively small group of seasoned experts, many of whom are older, known each for decades and abide by spoken and unspoken agreements not to publicly criticize others by name or expose issues to authorities.

In the 1970s, many industry insiders had a compelling mission - helping hundreds of thousands of families avoid incredibly high prices and live a simpler life that was more connected to nature and their own hard work. That mission is still a prominent driver for much of the wood heater industry, but instead of struggling to weld together enduring, affordable stoves, they are now filing 30-day notices, 60-day notices and a dizzying array of other paperwork.

One result is consolidation and a banding together to fend off stricter regulations and more oversight. Many manufacturers feel that they need to keep as much data as possible away from the government to survive. When outdoor wood boilers took off, just like when sales volumes of exempt single burn rate stoves soared, most industry insiders stayed quiet publicly, even when they privately fumed over the damage that these unregulated devices were causing to airsheds and the industry’s reputation. Top industry leaders also stayed quiet while highly exaggerated efficiency values proliferated and deployed their lawyers to ensure all stoves could be treated as 75% efficient or higher for IRS purposes.

Issues surrounding 30-day notices and suspension reports are not at the core of the struggle for the future of how well wood heaters work in the hands of homeowners, but they illuminate a slice of the struggles facing industry, EPA, state regulators and the air quality community as our country decides which renewable technologies will power our future. Once represented by the Washington DC based trade group “Wood Heat Alliance” in the 1980s, wood heaters are now represented by the HPBA that also represents more profitable gas and propane appliances and struggles to fit in to the renewable sector that thrives on greater transparency.

Recommendations

1. The 30-day notifications sent to the EPA are currently only being made through a Freedom of Information Act request, rendering them far less useful than if the EPA maintained a publicly available database. This could also provide transparency of key information that is not available elsewhere.

2. If state regulators who have labs in their state visited labs periodically to witness even part of a certification test, it could provide valuable insight and potentially oversight into the nature of testing procedures for states, the EPA and others.

· Oregon is by far the most important state since Omni and PFS-TECO are located there, and has a unique and longstanding role in stove regulation that predates the EPA’s role. The state also has areas where excessive wintertime wood smoke is a serious problem.

· NESCAUM has risen to become the most active and informed entity in the wood heating testing community. Its staff and member states can use their expertise to put pressure on the EPA and assist them in developing future test methods.

· California often plays a large role in national air quality policy, the state has taken a back seat for stationary wood heaters so far. Their engagement could help.

3. Manufacturers should start to routinely comply with the rule that they send a report with data on suspended tests within the required 60-day period. EPA also needs to enforce this regulation and clarify what those reports should look like. HPBA could take a leadership role in highlighting this regulation for labs and manufacturers.

4. The EPA and/or states should start conducting audit testing of stoves to better understand the application of crib and cordwood test methods.  This would assist all stakeholders to focus on vital issues about lab testing during a time when wood and pellet heating is under public scrutiny as a renewable energy solution.

Six tips to buy the right pellet stove

Retailers say BTU output can be most confusing issue

Glenn Robinson is one
of many retailers struggling
to help consumers avoid
relying on manufacturer
claims about BTU output.

Updated on Jan, 7, 2021 - Glenn Robinson has been selling and installing pellet, wood and coal stoves in Pennsylvania for 11 years, and one of the biggest problems he faces is sizing the stove.  “I became tired of false information from manufacturers about how many BTUs they claimed their stoves put out” he said in a recent interview.  “Customers see these exaggerated BTU numbers from a small stove and think it will heat their home, but it won’t.  The result is that the stove is undersized and there is premature wear and tear.  One model from a big name brand would only last for 3 – 4 months before needing repair or even full replacement,” he said.

Glenn is not alone in identifying exaggerated BTU listings as one of the biggest problems consumers face in buying a stove.  Scott Williamson, a Massachusetts pellet installation and repair technician says that he sees stoves “all the time that are being run on high 24/7 and pellet stoves just aren’t designed to do that.”  Both installers say that under sizing of pellet stoves is one of the biggest problems, and urge customers to consider larger (higher BTU output) stoves if they live in average size homes in the northern half of the country and plan to use the stove a lot.

Buying a pellet stove can be a confusing process for consumers (but as of 2021 high efficiency pellet stoves and installation costs are eligible for a 26% federal tax credit!)  Retailers are likely to push the brands they sell and manufacturer websites don’t tell the whole story.  Objective, third party reviews are rare and often outdated.  Consumer Reports did a pretty good review in 2009 but used very limited criteria and didn’t test for durability.  The Alliance for Green Heat (AGH) also undertook third party testing in 2015 and issued a detailed online report on some issues including BTU output, maintenance and efficiency. (Like Consumer Reports, AGH conducted completely independent testing by purchasing all the units and doing all of our own testing.)

This blog identifies and discusses six rules for consumers to keep in mind when buying a pellet stove, with a focus on sizing.  This is not an exhaustive list but it’s a good place to start: 1. Don’t undersize, 2. Beware of cheaper stoves, 3. Look for range of heat output, 4. Understand maintenance requirements of the stove, 5. Look for cleaner stoves and 6. Beware of stoves with no efficiency on the EPA list

AGH tested six popular pellet stoves.
Almost all performed well during
intensive 30 day testing, but did not
live up to some manufacturer claims.

Pellet stoves can be a very effective and affordable way to provide primary or secondary heat for your home without the smoke that wood stoves often create in the hands of the typical user. Wood stoves require lots of work on the fuel side of the equation, but pellet stoves involve more work on the appliance side of the equation. 

The Alliance for Green Heat also monitors advertising of pellet stoves and has found over the years that the great majority of companies vastly overrate the amount of heat their stoves put out.  The EPA list of certified wood and pellet stoves is not perfect but it remains the best source of BTU output for consumers. 

Most EPA-certified pellet stoves are listed as producing a maximum of 25,000 – 40,000 Btu and minimum of 7,000 – 13,000 Btu. The average pellet stove on the EPA list, according to data provided by third party test labs, put out a maximum of approximately 31,800 Btu and a minimum of approximately 10,050 Btu. 

The stove with the highest maximum Btu on the EPA list is the Harman P68 at 53,500 Btu (advertised at 71,200 Btu input).  When a stove manufacturer lists Btu input, it refers to amount of Btus in the fuel, if you were to get 100% of those Btus into the room.  But the average pellet stove is around 73% efficiency, which means you will get 73% of the fuel’s potential heat into the room.  (This is similar to the AFUE – the annual fuel utilization efficiency – that is used on gas and oil boilers and furnaces.)

The stove with the lowest maximum Btu is the Thelin Gnome pellet stove that puts out up to 9,000 Btus.  However the company advertises three times that - 27,000 Btus - without any explanation.  Manufacturers usually exaggerate Btu, thinking that it will make their stoves more attractive, but in the case of the Thelin Gnome, there are people looking for stoves to heat very small places and the exaggerated Btu output may make them think even the Gnome is too big.

Here are six critical things for consumers to keep in mind when purchasing a pellet stove:

1.       1. Don’t undersize. If the stove is going to be your primary heat source you will likely need a medium or large pellet stove, even if a smaller unit advertises high BTU output.  Ignore BTU numbers on manufacturers websites and literature and check the EPA list.  The maximum output for pellet stoves is in the 30,000 – 50,000 range, enough to heat all or most of a small or medium house in most climates. “Don’t plan to run the stove all the time at its highest setting,” warns Scott Williamson “or you will be calling someone like me to fix it quicker than you think.”  When we tested six popular pellet stove models, we calculated an output of no more than 21,000 BTUs, far below what the EPA listed and even farther below what manufacturers claimed.

It is possible to oversize the stove and that can be a problem, but is not nearly as common as under sizing.  “For example, the Harman P68 is notorious for being installed in small areas like mobile homes but they gunk up when they aren't allowed to get up to temperature for a bit before they shutdown,” says Scott Williamson.

2.      2. Beware of cheaper stoves. There are some good budget wood stoves on the market, but with pellet stoves, you are more likely to get what you pay for than with wood stoves.  “If you want a reliable stove that puts out a lot of heat, we urge customers to ignore pellet stoves under $2,500,” says Glenn Robinson.  Scott Williamson generally agrees but has seen some basic stoves like the Pel Pro in particular holds up very well.

3.      3. Check for range of heat output.  Most stoves can put out about 3.5 times more heat at their highest setting, compared to their lowest.  Some stoves have a tiny range, putting out only 1.5 times more heat at their highest setting.  If you live in a more moderate climate, in the early fall and late spring, you may want just a little heat, and still have the capacity for much greater heat output on the coldest days and nights of winter.  All other things being equal in a stove, you may want a stove with a larger range of heat output and you can check the range of all stoves on the EPA list of certified stoves. In our tests, we found that the Enviro M55 insert ran continuously for an impressive 49 hours on its lowest setting with a tested hopper size of 60 pounds and it ran for 22 hours on its higher setting.  However, with a 37-pound hopper, the Englander 25 PDVC only rain for 15 hours on its lower setting and 13 hours on its highest setting, indicating a very low turn down ratio.

4.       4. Understand maintenance requirements. If you don’t clean your stove regularly and have it professionally serviced once a year, don’t expect high BTU output.  Most consumers get subpar performance from stoves and have to repair them more often because they are not maintaining their stoves according to the owner’s manual.  Pellet stoves are not like wood stoves: they have lots of moving parts and need cleaning of the burn pot and inside the stove on weekly, and depending on the stove, a daily basis.  Pellet stoves that are not cleaned regularly can lose 10% or more of their efficiency – and their heat output, and lead to costlier repairs. Understand the daily, weekly and annual maintenance requirements from the start and don’t put them off.  When we tested six popular pellet stoves, we found that the three more expensive ones (Harman, Quadra-Fire and Enviro) could go for a week or more without cleaning the burn pot.  However, the Englander, Ravelli and Piazzetta needed daily burn pot cleanings.

5.       5. Look for cleaner pellet stoves and ones that are 2020 certified.  Pellet stoves are far cleaner than wood stoves, even if they both have the same particulate matter in grams per hour.  Particulate matter is the tiny stuff that smoke is made out of and pellet stoves should not have any visible smoke after the 3-minute start up.   The average pellet stove used to put out about 2 grams of particulate per hour.  But since the new EPA regulations took effect in 2015, pellet stoves have become even cleaner and more efficient.  As of April 2020, more than half of the 2020 certified pellets stoves emit 1 gram or less per hour. This makes pellet stoves more suitable in more densely populated suburban and even urban areas.  Choosing a cleaner pellet stove means a cleaner flue pipe and cleaner air around your and your neighbors’ homes. You can now easily search for the cleanest pellet stoves on the EPA's new searchable database.

6.       6. Beware of efficiency numbers on manufacturer and retailers websites.  As with BTUs, manufacturers routinely exaggerate the efficiency of their stoves on their websites, so if efficiency and saving money is important to you, check the EPA list of stoves for efficiency ratings.  Until May 2020, many companies still hadn't even reported their efficiency to the EPA, but thanks to new regulations, all companies have to test for and disclose their efficiency.  Pellet stoves range from 58 to 87% efficiency, so do your homework and check the EPA list.  As of Jan. 1, 2021, consumers can get a 26% tax credit when buying and installing pellet stoves that are 75% efficient or higher. Click here for more details.

Do not rely on Manufacturers Certificates that claim their stoves are eligible for a federal tax credit without first checking the efficiency on the EPA's searchable database of certified heaters.  Even large companies that make good quality stoves like Jotul and QuadraFire have claimed that stoves as low as 66% efficiency are eligible for the tax credit.  The credit is supposed to be for stoves over 75% efficiency.  

The EPA used to allow companies to calculate efficiency based on a default of 78% efficiency, even though most pellet stoves are below that, explains Ben Myren, who runs one of the stove test labs approved by the EPA. The result is a 5-10% exaggeration of some stoves on the EPA site, something that the EPA has not publicly acknowledged. (Some incentive and change out programs - Maryland, Massachusetts and New York - require that the stove have an efficiency listed on the EPA list to get the full rebate.)

Appreciating these six factors are likely to help you make a better decision, but we also encourage consumers to rely on feedback from friends, neighbors and others who own pellet stoves. One site that can be helpful for research is hearth.com.  

A final note of caution is to take advertised hopper size with a grain of salt.  Most manufacturers also exaggerate hopper size.  Of the six models we tested, Harman and Ravelli exaggerated their hopper size by 15 – 18%, while Enviro didn’t exaggerate at all.  Choosing a stove with an advertised hopper size of 50 – 60 pounds can be a good idea, as it means the hopper will likely hold 45 – 55 pounds and you can empty an entire 40 pound bag in it when its low.