Stove manufacturer documents scores of errors in NESCAUM report

NESCAUM responds to Morrissey as he issues Part 2 of his review

Tom Morrissey, owner of Woodstock Soapstone, a wood stove manufacturer, has written a blistering critique of a report that claimed the EPA wood stove certification process is “dysfunctional.”  

Tom Morrissey at his factory 
in West Lebanon, NH

The review by this independent manufacturer further ratchets up a conflict that has engulfed a section of EPA’s Office of Air and Radiation.  The original report, “Assessment of EPA’s Residential Wood Heater Certification Program" by the Northeast States for Coordinated Air Use Management (NESCAUM), issued in March 2021, was based on a review of all test lab certification documents that had been sent to EPA to certify stoves to EPA’s regulatory standards.  The review was conducted jointly by the Alaska Department of Conservation (ADEC) and NESCAUM, with funding from the New York State Energy Research and Development Authority (NYSERDA). 

(June update: Tom Morrissey released part 2 of his review on June 15 and three days later, NESCAUM released their rebuttal to Morrissey's initial review.  NESCAUM appears to be standing behind its entire report and did not find any merit in Morrissey's critique.  On page 21, NESCAUM also addressed editorial comments in AGH's blog. Part 2 of Morrissey's critique mainly focuses on burn rate requirements adopted by ADEC as a deficiency, but not used by NYSERDA's IDC test method.  Morrissey also describes why the IDC will likely result in lower efficiencies because BTUs in the tail of the burn are not included and questions if the EPA should ever approve a test method where underlying calculations are not public.  AGH agrees with a substantial amount of the content in both the NESCAUM report and Morrissey's rejoinders and believe it's important for EPA officials, states and experts to consider both.)

NESCAUM and ADEC accused the EPA of running a dysfunctional certification program that “is easily manipulated by manufacturers and testing laboratories” and “EPA has done little to no oversight and enforcement.” Morrissey counters that NESCAUM and ADEC also have produced a dysfunctional assessment of the EPA program that is full of “error, bias and conflict of interest.”

We have excerpted key parts of Morrissey’s review below.  The full review, with scores of photos, can be downloaded here.  The Alliance for Green Heat believes it is important to consider both the NESCAUM report and rejoinders from Morrissey and another one from veteran lab technician Ben Myren together.  We believe there is substantial truth in all three of these documents.  Our initial response to the NESCAUM report was that it “overstated” its case, and AGH welcomes expert rejoinders that bring some balance to the conversation.  However, AGH still believes that EPA should take the NESCAUM report seriously because it is clear that the EPA certification and enforcement programs need significant improvement, and that these have been underfunded, understaffed and overlooked within the EPA.  

AGH also agrees that much of ADEC’s and NESCAUM’s review was hastily done without sufficient fact-checking.  The report carries an unfounded degree of authority that is now reverberating throughout the wood stove industry and its state and federal regulators, and the wider public is less likely to see these rejoinders.  NESCAUM and ADEC now have the opportunity to respond and explain some of the allegations in Morrissey's review or continue to stand behind that data that led to their conclusions. Numerous individuals have approached northeastern state government agencies who are members of NESCAUM, urging them to distance themselves from the report and not let their agency names be used on such reports in the future without more due diligence.

In early April, in response to the NESCAUM report, the EPA announced they were conducting an in-depth review of the certification process.  They placed most of the blame on the test labs and third party certifiers.  Morrissey’s review may cause the EPA to rethink its strategy and not put undue trust in the finding of the NESCAUM report.  Morrissey’s review is significant because he is not a member of the wood stove industry association and has often taken sides for and against industry interests – and the EPA’s. This is part 1 of his review and he expects to complete the second part in June.

AGH is concerned that the NESCAUM report, media coverage of it, and Morrissey and Myren’s rejoinder put so much focus on the inherent problems with wood stoves and the pollution they can cause, that the benefits of pellet stoves get overlooked.  Virtually nowhere is there recognition of the technology and reliability of pellet stoves and boilers as a far cleaner, renewable energy technology that can help households and businesses get off fossil heating fuel.  

Excerpts:

REVIEW (PART 1)

of

“ASSESSMENT OF EPA’s RESIDENTIAL WOOD HEATER CERTIFICATION PROGRAM” Written by NESCAUM, March 2021 

Page 1: In March 2021, the Northeast States for Coordinated Air Use Management (NESCAUM) published a document entitled “Assessment of EPA’s Residential Wood Heater Program (“Assessment”). The “Assessment” is the result of a review conducted by NESCAUM “in collaboration with the Alaska Department of Environmental Conservation” (ADEC). 

The “Assessment” is intended to influence “policymakers” by claiming 1) that the EPA Certification Program is dysfunctional and a systemic failure, 2) that there are a significant number of discrepancies and omissions in test reports submitted to EPA for approval, 3) that EPA has failed to conduct compliance audits, and 4) that the NESCAUM and ADEC could do a better job than EPA in, a) deter- mining which stoves are in fact the cleanest burning and, b) developing a test method for certifying wood burning appliances. NESCAUM has provided scant data to back up these major claims, and some of the data that it does present is riddled with discrepancies, omissions, bias errors, and conflict of interest, as detailed below. Bias is evident everywhere; in tone and use of language, in lack of transparency, in the selection of subjective criteria to attempt to discredit test methods and results, and in its attempt to advance NESCAUM’s own agenda4 with its “policy recommendations.” The bias is so pervasive that it undermines much of the “Assessment.” 

Page 3: In order to assess NESCAUM/ADEC’s data analysis and conclusions, we need to first look care- fully at its data collection methods and ask whether the underlying data is complete, credible, and unbiased. The main focus of this Part One of A Review of the “Assessment” is on how data was collected and tallied on “Summary Review Sheets” by ADEC. 

On the following pages I raise concerns about quality control, bias, and conflict of interest in NESCAUM/ADEC’s acquisition of data. It is clear that NESCAUM/ADEC reviewers lacked objectivity in assessing information, particularly with regards to the ASTM E-3053 method, and they reviewed individual test reports (knowingly or not) with the intent to discredit the ASTM E-3053 and advance their own interest in promoting the IDCTM method. 

Page 4: All ADEC data sheets that I have reviewed are undated and unsigned. Most have few, if any comments.  Many have unfilled spreadsheet boxes (data not collected). All of the ADEC reports of stoves made by Woodstock Soapstone Company have serious omissions, errors of fact, misreporting, and untrue statements. Of six Woodstock Soapstone Company models approved to the EPA 2020 Standards, two models were missing entirely, and one model was reviewed twice, on separate data sheets that were inconsistent and did not match (i.e., different reviewers looking at the same data, or the same reviewer on different dates looking at the same data). The fact that ADEC reviewed the same data twice, and the two completed spreadsheets are markedly different, speaks to the concern (also noted in footnote #2) about quality control. 

Page 5: On the pair of summary sheets where NESCAUM/ADEC inadvertently reviewed the same test report twice, there were 25 discrepancies between the two reports, including errors of transcription, op- posing claims that data was or was not reported, rounding errors, conflicting or inconsistent “flags” and numeric/arithmetic errors. This is not reassuring in terms of NESCAUM’s claimed consistency in generating the summary results, and raises the issue of whether NESCAUM’s own consistency and repeatability should be the subject of an audit. 

These two ADEC Summary Reports are reproduced on page 6, and an explanation of most of the errors on page 7. For simplicity sake, I refer to the report that is captioned Model 210a (but really Model 210) as Report A, and the Report that was (correctly) reviewing Model 210 as Report B. Both reports were posted and properly labeled on the Woodstock Soapstone website. But that’s not the point; these two reviews of the same report should produce similar, if not identical results, but they did not. 

These two Summary Sheets, which review the same test report,8 disclose obvious problems in the research and reporting methods employed by NESCAUM/ADEC, and the ability/willingness of NESCAUM/ADEC to impose meaningful quality controls on their inquiry. As noted early in this review (see footnote 2), there is little, if any, evidence of NESCAUM/ADEC cross-checking or vetting of the reviews or data in the “Assessment”. The task of auditing the “Assessment” and validating its so-called “data” and its various claims will now, probably, fall squarely on EPA. 

This is the central irony of this situation; NESCAUM’s own data and reporting is guilty of the same failures it attributes to EPA, namely failures in transparency, documentation, and auditing its own work product for consistency, impartiality, and accurateness. The EPA will now become responsible for cleaning up the NESCAUM mess. 

Page 8:  For the purpose of this initial review, I will focus mainly on stoves made by Woodstock Soap- stone Company. Next, I will examine the ADEC Summary Sheet for our Model 202/204. This is a “plain vanilla” Summary Sheet, compared to Model 210, on pages 6 and 7, above. 

ADEC encourages manufacturers to “review their certification test report summaries and submit corrections, and that any substantiated errors or corrections will be applied to the summary sheet.” So, I’ll just make the corrections here. On our Model 202/204, the initial ADEC summary sheet (see next page, LEFT COLUMN) makes the following errors (WHICH CUMULATIVELY TOTAL 13 FLAGS). I intend to address THREE ADDITIONAL RED FLAGS (related to Documentation of 1) run appropriateness, 2) run Validity, and 3) run anomalies on Part 2 of this Review. 

What is fascinating is that between early April 2021, when I downloaded the original Summary Review Sheet, and today (mid-May, 2021), ADEC performed an additional review and corrected some of its original errors, and made some new errors. Here are comments on the initial ADEC Summary Sheet. Comments on the revised Summary Sheet are on the next page. 

Page 10: According to the ADEC “PROCESS”, I am supposed to address all of these “issues” by

One of the many photos that
appear to provide evidence
contradicting ADEC "flags"

discussing them with ADEC, and maybe submitting modified or reformed test reports. Then ADEC will makes changes as it deems appropriate. Or not. 

Page 14: The “Assessment” claims that “90% of the stoves tested using ASTM E-3053 used debarked wood or failed to provide information about whether there was bark on the fuel.” (Assessment page 38) The “Assessment further claims that “61% of the stoves tested with ASTM E-3053 used squared wood for more than 50% of the pieces” (Assessment page 33), including the stove immediately above (Model 205) and the fuel for Model 202/204, pictured on pp 10-11. 

Based on my review, I cannot believe either of these claims. If the basic data underlying the “Assessment” is defective, then its claims of numerous deficiencies in testing and reporting, and its criticisms of ASTM E-3053 are suspect, because they are based on bad data. 

Page 19: I hope to have Part 2 in mid-June. There is a lot more to unpack in the “Assessment,” including: 

* The overall “Assessment” review strategy, and whether it is a credible basis for proceeding to the conclusions that the “Assessment” tries to come to. This strategy is basically to make a list of each and every requirement imposed by the NSPS, and then see if each and every item on the list can be identified in test reports, no matter how obscure or irrelevant the requirement might be. Otherwise, deficiencies are claimed by NESCAUM/ADEC without any apparent oversight or review, or any basis in fact. 

* The nexus of firebox size and calculation, loading direction, fuel length, and loading density. These are the second set of elements that the “Assessment” uses to criticize ASTM E-3053. 

* I’ll review this sentence, and how it has spawned innumerable “flags” (i.e., claims of violations of the NSPS) in the “Assessment’s flag-collection effort."

New York and Canadian companies win technology challenge to automate the wood Stove

Jonathan Male, director of the DOE's Bioenergy
Technology Office, announces the winners.
Photo: Sam Kittner for Brookhaven National Lab.

(Washington, D.C.) – Two companies with years of experience in electronics and stove design won coveted first and second prizes in the 2018 Wood Stove Design Challenge, held in Washington DC from November 9 – 13. 

Manually operated wood stoves are extremely common throughout the northern US, Canada and Europe but no one has yet popularized a solution to prevent them from emitting excessive smoke in the hands of operators.

Wittus, a company based in Pound Ridge New York, teamed up with German engineers and won first prize for both the automated and thermoelectric categories with a living room unit that also heated water for space heating

The Wittus team who won first place in both
the automated and thermoelectric categories.
Photo: Kittner for BNL.

and generated an average of 161 watts and a maximum of 268 watts over the 2.5-hour test period. Total power output over the test period, net of parasitic losses, e.g., pumps and fans, was 276 watt-hours of electricity. The use of thermocouple sensors and fans facilitated clean and efficient combustion.

Stove testers from Brookhaven National Lab and
New York Department of Health.
Photo: Kittner for BNL.

Second prize went to Stove Builders International (SBI) a Quebec based company that designed a simple, affordable stove that allowed the operator to select high or low heat output and used a low-cost control board and thermocouple sensors to ensure that the stove burned cleanly.

Second prize in the thermoelectric category went to California based Vulcan Energy, who

SBI, a prominent Canadian stove manufacturer
spent years developing automated features.
Photo: Kittner for BNL.

developed a thermoelectric generator for the gravity fed Wiseway pellet stove that generated an average of 123 watts, and a maximum of 139 watts, during the 2.5-hour test period. Total power output over the test period, net of parasitic losses, was 235 watt-hours.

The People’s Choice award, based on votes from the general public, went to 509 Fabrications, for their unique gravity fed pressed log stove.

Key partners in the Challenge included Olympia
Chimney, and CSIA, and NFI installers from
Winstons Chimney and  Sugarloaf Chimney.
Photo Kittner for Brookhaven National Lab.

The goal of the Woodstove Design Challenge is to demonstrate how improved designs including sensors and computer controls can make wood stoves cleaner and more efficient. The technology boom of the past few decades has largely missed the wood stove industry, yet innovation still holds great promise. 

Researchers including Brookhaven National Lab, with support from the New York State

Fred Leavitt won 2d prize in thermoelectric
with Jonathan Male, DOE, Ramesh Koripella,
Sandia National Lab and John Ackerly, AGH.
Photo: Kittner for BNL

Energy Research and Development Authority (NYSERDA), have been developing new methods for the next generation of assessment protocols for wood heating appliances. Currently, most stoves in America are tested for EPA certification with standardized fuel pieces and spacing. Research has focused on in-home use operational practices, user fueling patterns, and new real-time measurement method techniques with random loading patterns and variability in piece size to better replicate real-life conditions.   

Automated stoves that are designed and tested with this new robust cordwood test method can help improve woodstove designs and in-use performance leading to higher efficiency and lower emissions.

Les Otten of Maine Energy Systems with Julie
Tucker of the USDA Forest Service.
Photo: Kittner for Brookhaven National Lab.

A team from Stony Brook University also competed in the event with a prototype that featured a unique wood drying and preheating chamber. The stove did not win a prize but offered students a rich opportunity to engage with national stove design and testing experts. A full list of the competing teams can be found here. 

Partners for the Design Challenge include NYSERDA, the Department of Energy’s Bioenergy Technology Office, the U.S. Forest Service, the Osprey Foundation and Olympia Chimney. The automated stoves were tested by Brookhaven National Lab. A complete list of partners and sponsors can be found here.

Meet the Teams: A New Zealand entrepreneur automates the wood stove - without using electricity

This post is the first in a series of technology and innovation blogs introducing the 12 teams participating in the 2018 Wood Stove Design Challenge in November.

By John Ackerly and Shoshana Rybeck, Alliance for Green Heat 

Alistair Gauld with the VcV stove. 

Variable Choke Venturi (VcV) technology has come a long way from New Zealand, where it was invented over a decade ago. It is a clever, simple device to improve combustion in wood stoves that is reliable and does not require electricity. Brian Gauld, an accountant in New Zealand, met the VcV inventor and bought the rights to it, convinced that it held the secret to cleaning up manually operated wood stoves.  

The VcV is a valve controlled by the draft generated by the stove when burning, but making it work effectively on a wood stove and then getting that stove certified was a much longer journey than Brian initially expected. There is a huge need for an automated, “idiot proof” stove in New Zealand, but the market is not big enough to justify the costs so Brian set his sights on the North American market. In 2008, he hired Ben Myren to help integrate the VcV valve into a stove. So began one of the most innovative and promising new stove technologies on the US market.

The Promise of the Technology

Simply put, the valves increase or decrease the amount of combustion air entering the stove in response to static pressure changes at any given time, depending on how much combustion air the stove needs. Ben and Brian realized that by combining two VcV valves—one for primary air and one for secondary air—the VcVs could reduce particulate matter (PM) emissions even more, hoping that would be the key to reliably meeting the EPA’s 2020 standards. Brian and Ben were well on their way to building an automated stove without electricity, whereas other automated stove designers were trying to do the same thing with sensors, electronics and computer chips. The marketplace for wood stoves has a lot of folks who dislike the thought of a wood stove that needs electricity to operate. The simplicity of the Flamekeepers’ technology could go a long way to ensuring that the stove would not just operate well in the lab, but also in the hands of the average consumer. And that has been the great challenge of the wood stove since it was invented years ago.

Labeled diagram of on a VCV valve

From the moment the consumer lights the stove, they can shut the door, sit back, and enjoy the heat until it needs to be reloaded, according to Ben Myren. At the time of ignition, the second VcV is engaged, as explained in an illustrative informational video on the model. The Secondary VcV (S VcV), a disc attached to the secondary air inlet, rises and falls relative to static pressure, which increases and decreases with the amount of combustion taking place in the firebox. The S VcV functions all the time and supplies just enough secondary air during a burn to maximize combustion efficiency. Once the static pressure decreases at the end of the burn and more oxygen is needed to increase combustion, the P VcV disc goes down again. 

While most automated stoves and stove prototypes include a temperature sensor to help regulate air flow, thermometers require electronics and a control board which can be to be deceptively complicated and unhelpful to control combustion. Instead, static pressure can be a more reliable way to control what goes on inside the stove and what goes up the stove pipe. Ben says that temperature measurements can often be misleading when determining a stove’s combustion level and oxygen needs. 

When people hear about how the VcV works they think that it is very similar to a bi-metalic coil, which responds to heat, and closes down an air inlet as the stove gets hotter. Bi-metalic coils have been used for decades and a few manufacturers still use them even though they can be unpredictable during the lab certification process. Bi-metalic coils respond to heat, whereas the VcV responds to static pressure. While heat must move from the firebox to the coils, any change in combustion will automatically change the airflow, thus inciting an immediate VcV response. Therefore, Ben credits VcV technology with being far more efficient and simply better than a bi-metalic alternative. 

Advantages of Simplicity 

EPA test stove on scale with test filters 

being preheated in the background.

The simplicity of the VcV comes from the concept of letting the stove’s combustion determine its air flow needs at any given moment, which inherently reduces the operational errors. While the user may set the stove to a burn setting that is too low, the disc technology will not lift until the combustion, as determined by the static pressure, is at a high enough level to safely cut off the air flow. The stove will eventually go to that low setting, but not until the static pressure indicates the time is right. Therefore, consumers have the autonomy to choose the burn level they want, but the stove will only reach that level when it is able to do so cleanly. Ben also added a catalyst to the stove to ensure that it would operate well under 0.5 grams an hour and meet the 2020 EPA cordwood emission limits.

Brian and Ben also recognized and addressed one inherent problem in stove installations all over the US: varying heights of chimneys. The engine of a stove is its chimney, which creates a natural draft to pull both the primary and secondary air into the stove.  But homes can have chimneys anywhere from 10 to 30 feet high, which dramatically impacts combustion, and stove manufacturers have no way to address this as they build to the height of the chimney in the test lab—which is 14 to 16 feet. Brian and Ben realized that they could fit the VcV with heavier or lighter discs so that the stove could work well with any chimney height.  

At least one North America company has applied for licensing of the VcV technology and a stove with the VcV may also be licensed in New Zealand.  

Team Goals

Brian and Ben are no strangers to the Wood Stove Design Challenge. An early prototype of the stove competed in 2014. These prototypes showed great promise and led to the stove being the very first North American wood stove to be tested and certified with cordwood.

Ben Myren lighting a stove at the
2013 Wood Stove Design Challenge

Brian’s son Alister Gauld is also a part owner of the company and will be in Washington in November when the stove will be put through its paces by professional stove technicians to see whether it performs as designed. While Ben and his lab tech Eric Schaefer were just hired by Brian on a daily basis and have no financial stake in the company, they are proud of helping to develop the first non-electric automated stove in North America that can help clean up our air-sheds far better than stoves that can be left to smolder by their owners. The beauty of the VcV is that the owner doesn’t even have to know how it works inside or that it is a groundbreaking stove. From the outside it will look exactly like a traditional stove that will keep the house warm in a power outage.

Contact the team

Brian Gauld

brian@thevcv.com

Ben Myren 
myren.ben@gmail.com

Alistair Gauld
Alistair@harts.co.nz

Eric Schaefer

ericsschaefer82@gmail.com

Opinions of top wood stove industry insiders revealed in 1998 interviews

The late Paul Tiegs, one of the
greatest authorities on wood
stoves, conducted the
interviews for the EPA. 

Long before the regulatory debate about wood stoves heated up in the 2010s, the EPA commissioned a series of fascinating interviews with the top wood stove experts in the country on a host of technical and policy issues.  These interviews give a glimpse of the opinions and philosophies of industry and academic leaders at a time when they apparently felt free to go on the record about what became controversial topics. 

The content of these interviews remains very relevant today for anyone interested in a behind-the-scenes look at many of the underlying issues in the 2015 EPA stove and boiler regulations.  The interviewers – Jim Houck and Paul Teigs (who are top experts themselves) – asked questions ranging from whether masonry, pellet, boiler and furnace appliances should be regulated, to the vulnerabilities of catalytic stoves, to how lab testing can better reflect real world use of stoves. 

These interviews remain a valuable resource because each of the nine experts was asked the exact same questions.  Thus, if you are interested in masonry heaters, or catalytic or pellet stoves, or how labs coax the best numbers from stoves, it is relatively easy to scroll down and see how each person answered the question.  Of the nine interviewees, four are from industry (John Crouch, Bob Ferguson, Dan Henry and Michael Van Buren), two from test labs (Rick Curkeet and Ben Myren), two from academia (Skip Hayden and Dennis Jaasma) and one from EPA (Robert C. McCrillis). Their full titles and affiliations are at the end of this blog along with the full list of questions asked.  The full set of questions and answers are in Appendix B on page 58 and can be downloaded here (pdf).

In general, Bob Ferguson and Dan Henry tended to oppose further regulation, and felt, for example, that pellet stoves and wood-fired central heating appliances did not need to be regulated.  Ben Myren tended to favor a blanket approach of closing loopholes and regulating all appliances.  This difference in views between two industry experts and one test lab expert can be viewed through their respective economic interests and how it would affect their livelihoods.  But these interviews also show deeper philosophical differences and illuminate the reasons for their positions, whether they concern the health impacts of wood smoke, consumer protection, profitability, practicality of test method changes, etc.

We have chosen to reproduce the answers to two questions and invite readers to refer to the full set of interviews to find issues that they may be more interested in, such as the impact of wood species on emissions, stress testing to see how durable stoves are, and options to promote or require education or maintenance of stoves by consumers. 

When the Alliance for Green Heat began ten years after these interviews in 2009, much of the content had already been seemingly lost or obscured.  Very few people, for example, knew of the origin or impact of the 35:1 air-to-fuel ratio loophole that allowed pellet stove manufacturers to make low efficiency stoves in order to avoid regulation.  Right up until 2014, state and federal government agencies, along with top industry outlets, continued to propagate myths about pellet stoves.  Even the EPA never advised consumers that uncertified pellet stoves were likely to have lower efficiencies due to the 35:1 loophole they created.  These interviews provide the best information anywhere on how this came to be and what impact it had on the pellet stove industry and consumers.

We chose the question about whether central heaters should be regulated because this turned into one of the biggest issues in the 2015 regulations.  Only one interviewee – John Crouch – saw a causal relationship between the rise of outdoor wood boilers and the 1988 emissions regulations. 

Question: The 35:1 air-to-fuel ratio cut-off for certification has produced two classes of pellet stoves — those that are certified and those that are not. The latter class may have models that are less efficient and have higher emissions than the former. Should the regulations be amended to close the loop-hole and discourage the practice of intentionally designing models with a higher air-to-fuel ratio to avoid certification?

John Crouch, HPBA's
foremost wood stove expert.

John Crouch, HPBA: I wouldn’t use the term “close the loop-hole”. I would say, “is the proper place to cut off the definition of a wood heater?” We all know the whole discussion during the Reg-Neg ignored this emerging category of pellet stoves. So this gets back into my other broader comment, which is, instead of going back in and changing the NSPS in a piecemeal fashion, there needs to be a true revision of the whole thing that deals with the category of pellets and masonry heaters and outdoor furnaces.

Rick Curkeet, Intertek: Yes. The way to amend the regulation is to simply remove the 35:1 air/fuel ratio exemption. This has never been required by fireplaces (they meet the 5 kg/hr minimum burn rate exemption criterion anyway). Pellet units are readily able to meet emissions requirements and the exemption only encourages making these units less efficient to avoid the regulation.

Bob Ferguson, Consultant: The 35:1 cutoff was intended for fireplaces. However, pellet stoves are the only product that even take advantage of the air-fuel exemptions. Fireplaces generally use the burn rate exemption. Pellet stoves probably don’t need to be regulated at all. They are all quite clean burning. Let the marketplace decide if exempt stoves are acceptable. If pellet stove users demand products that use fewer pellets (more efficient), the manufacturers will respond. 

Skip Hayden, Researcher: Yes. In Canada, we recommend that people buy only EPA-approved pellet stoves. We have developed a high ash pellet stove that's operating around 85% and its emissions are about 0.3 g/hr or less. 

Dan Henry, a founder of Quadrafire
stoves is one of industry's most
articulate spokesmen.

Dan Henry, Aladdin: There is no data that indicates that even a poorly operating stove is a dirty burning appliance. They are inherently clean, becoming more and more reliable, and don’t fix them if they aren’t broken.

Dennis Jaasma, University of VA: Pellet stoves are inherently clean burning unless there is something very bad about their design. I am not concerned about regulating the currently uncertified units unless their field emissions are bad compared to certified stoves.

Robert C. McCrillis, EPA: Yes, all pellet stoves should be affected facilities and not subjected to that 35:1.

Ben Myren one of Amreica's most
thoughtful and experienced stove tester.

Ben Myren, Myren Labs:  I agree, no more loop-holes. The new technology stoves that are coming on the market are going to be totally new critters. I don’t think that turning down the air- to-fuel ratio, to make it whatever it is, should get you out of the loop. Some of those suckers have got to be just filthy. I mean you look at the flame. I’ve seen them burn at the trade show; you know, the glass is sooting up on the edges. You can just see it.

Michael van Buren was a technical
expert with The Hearth Products
Association, now HPBA

Michael Van Buren, HPBA: I don’t know what that loop-hole does, whether it really affects the operation of the stove and the efficiency of the stove.

Question: According to a Department of Energy survey out of the 20.4 million households that used a wood burning appliance in 1993, less than 0.3 million used a wood burning furnace as their primary source of heat. Are there enough wood-fired central heating furnaces in use to merit their closer evaluation? How many commercially available models are there? Are there emissions data for them? Should they be certified?

John Crouch: The [1988] EPA New Source Performance Standards killed the indoor furnace industry and created this little loop-hole which the outdoor furnace industry is beginning to exploit and kind of underscores the need for a more comprehensive wood burning regulation which sets out over a several year period to codify all forms of wood burning technology.

Rick Curkeet tested stoves for Intertek
labs and is one of industry's top experts.

Rick Curkeet: I don’t know how many new units are being produced but I’m sure it’s a very small number. Still, one really poor unit can be a significant problem if it’s in your neighborhood. There have never been any standards for testing this type of product for emissions and efficiency. However, we have adapted existing methods and can say that the performance range is very wide. Poor designs may be 30% or less efficient and produce nearly 100 grams/hr emissions rates. Good designs are able to approach certified wood stove performance levels.

Bob Ferguson: I don’t feel there are enough units being sold to merit any activity what-so-ever. There are only a handful of manufacturers. I don’t think there has been anything published--so if testing has been conducted, it is probably a good assumption that the numbers aren’t that good. They shouldn’t be certified, as you would have to develop test methods and standards. The country would be better off using the money to pay manufacturers to phase out of production, sort of like the agricultural method of paying farmers not to grow certain crops.

The late Skip Hayden also worked
at the US Federal Enercan Lab,
back when the federal government
focused more on wood heating.

Skip Hayden: The number of central wood furnaces in Canada, certainly in comparison to the United States, would be higher. In our Eastern provinces, it’s a relatively common add-on to existing oil furnaces. Generally, they are as dirty as can be.

Dan Henry: I think a lot of these are used in rural areas and considering the fuels that are out there, I don’t think they should be regulated. Maybe just a spot check of some sort. I think the only thing that would benefit would be the testing laboratories. If it emits particulate into an air shed where it can have an adverse effect on the industry (my ability to make a living), then yes.

Dennis Jaasma
also ran a combustion
 research lab at
Virginia Polytechnic
 Institute.

Dennis Jaasma: Yes, central heaters merit further evaluation. I don't know how many models are available. I think EPA has done some work on them, but I do not know any results. Yes, they should be certified. They are in danger of becoming extinct if they don't wind up with a certification program.

Robert C. McCrillis: In some localities I think these furnaces are a problem; I don’t know how many are commercially available. I think I can name off six or eight companies and each one makes several models, but I don’t know what the total market is, maybe 10,000 - 15,000 a year. The little bit of testing that we did here, says that they are probably on a par with a conventional wood stove. The way those things work, they have a thermostatically operated draft and when the thermostat shuts off the draft closes, so you get this real smoldering burning situation. Secondary combustion technology probably wouldn’t work. Possibly a catalytic technology would, but I just don’t think it stays hot enough in there. I guess that really depends on the impact.

Ben Myren: I don’t think they should be exempt for any reason. As to the rest of it--are there emissions data for them? I suspect there are. Should they be certified? Yes they should be certified. Nobody should be exempt from the process.

Michael van Buren: I think there should be some type of testing on them.

List of Experts Interviewed

Mr. John Crouch, Director of Local Government Relations, Hearth Products Association (CA) [now HPBA]

Mr. Rick Curkeet, P.E., Manager, Intertek Testing Services (IL)

Mr. Bob Ferguson, President, Ferguson, Andors and Company (VT)

Dr. Skip Hayden, Director, Combustion and Carbonization Research Laboratory (Ontario, Canada)

Mr. Daniel Henry, Vice President, Aladdin Steel Products, Inc. (WA) [now Quadrafire]

Dr. Dennis Jaasma, Associate Professor, Department of Mechanical Engineering, Virginia Polytechnic Institute and State University (VA)

Mr. Robert C. McCrillis, P.E., Mechanical Engineer, Air Pollution Prevention and Control, Division, U.S. EPA (VA)

Mr. Ben Myren, President, Myren Consulting (WA)

Mr. Michael Van Buren, Technical Director, Hearth Products Association (VA) [now HPBA]

Interview Questions

RWC Technology Review

Environmental Protection Agency Order no. 7C-R285-NASX

prepared by

OMNI Environmental Services, Inc.

Beaverton Oregon 97005

1. State-of-the-art of wood stove combustion and emission control technologies.

1. 1.1  Are in-home emission reductions as compared to conventional stoves shown in Table 1 for catalytic and non-catalytic certified stoves reasonable?
2. 1.2  Are efficiencies shown in Table 2 for catalytic and non-catalytic certified stoves reasonable?
3. 1.3  Can catalytic technology for use in wood stoves be fundamentally improved?
4. 1.4  Is the use of manufactured fuel (densified and wax logs) a credible emission

reduction strategy? See Tables 1 & 2 .

5. 1.5  For non-catalytic stoves the heat retention adjustment with refractory material of various densities can reduce particulate emissions. How big an effect can this have?
6. 1.6  Approximately one half of the particulate emissions occur during the kindling phase for non-catalytic wood stoves and more than half for catalytic wood stoves. Are there improvements in technology that can mitigate this problem? Can specially designed high BTU wax logs be used to achieve a fast start and reduce kindling phase emissions?
7. 1.7  Should masonry heaters with tight fitting doors and draft control be classified as a wood stove and be subject to some type of certification even though most weigh more than 800 kg?
8. 1.8  Are the emissions and efficiencies for masonry heaters, based on in-home tests, shown in Tables 1 and 2 reasonable?

9. 1.9  The OMNI staff feels the emissions per unit of heat delivered (e.g., lb/MBTU or g/MJ) is a more appropriate way to rank the performance of wood burning appliances than emission factors (lb/ton or g/kg) or emission rates (g/hr). — Comments?
10. 1.10  Default efficiency values are used for wood stoves. This coupled with the fact that emission factors or rates (not g/MJ) are used to rank wood stoves does not provide an incentive for manufacturers to increase the efficiency of their stoves. — Comments? Should an efficiency test method as described (FR v. 55, n 161, p. 33925, Aug. 20,1990) be required to be used and the results listed?
11. 1.11  Have certified stove design and performance improved since the first certified stoves? If so, how?

2. State-of-the-art of fireplace emission control technology.
1. 2.1  Are the emission factors and efficiencies for the in-home use of fireplaces and inserts shown in Tables 3 and 4 reasonable?
2. 2.2  There appear to be only a few practical design or technology options for fireplaces that will potentially mitigate particulate emissions. — What designs and technologies are available? What retrofit options are there?
3. 2.3  The use of wax fire logs reduces emissions over the use of cordwood. Can the formulation of wax logs be changed to produce even less emissions?
4. 2.4  What are the distinctions between a masonry fireplace and a masonry heater?
5. 2.5  As with wood stoves, the OMNI staff believe that the mass of emissions per unit of heat delivered is a better way to rank the performance of fireplaces than emission factors or emission rates.
3. State-of-the-art of wood-fired central heating furnace emission control technology.

3.1 According to a Department of Energy survey out of the 20.4 million households that used a wood burning appliance in 1993, less than 0.3 million used a wood burning furnace as their primary source of heat. Are there enough wood-fired central heating furnaces in use to merit their closer evaluation? How many commercially available models are there? Are there emissions data for them? Should they be certified?

4. State-of-the-art of pellet-fired wood stove technology.

1. 4.1  Are the emissions and efficiencies for the in-home use of pellet stoves shown in Tables 1 and 2 reasonable?
2. 4.2  The 35:1 air-to-fuel ratio cut-off for certification has produced two classes of pellet stoves — those that are certified and those that are not. The latter class may have models that are less efficient and have higher emissions than the former. Should the regulations be amended to close the loop-hole and discourage the practice of intentionally designing models with a higher air-to-fuel ratio to avoid certification?
3. 4.3  Have pellet stove design and performance improved since the first models were introduced? If so, how?

1. Ramifications of ISO.

5.1 The International Organization for Standardization (ISO) has a technical committee for developing emissions, efficiency and safety test standards for wood-fired residential heaters and fireplaces. (See Table 5 for comparison of the draft ISO method 13336 with EPA methods 28, 5G and 5H.) Do you feel that the EPA methods should be replaced with or be made comparable to an international standard?

2. Correspondence between in-home and laboratory emission test results.
1. 6.1  How accurately do certification tests predict in-home performance?
2. 6.2  How would you design research testing in the laboratory to simulate in-home use?
3. EPA Method 28 strengths and weaknesses.
1. 7.1  Method 28 is in part an “art”. Fuel loading density, fuel moisture, fuel characteristics (old vs new growth, grain spacing, wood density) and coal bed conditioning can be adjusted within the specification range of the method to influence results. In your experience what things have the most effect on particulate emissions? How much influence can they have?
2. 7.2  Burn rate weighting is based on very limited data and the cities from where the data were obtained are not very representative of wood use nationwide (see Table 6). How can the weighting scheme be improved to be more representative of the nation as a whole?
3. 7.3  The equation for the calculation of the air-to-fuel ratio as in Method 28A is in error. The error produces a small but significant difference in the calculated air-to-fuel ratio. Should the method be corrected or should it be left as a “predictor” of the air-to-fuel ratio?

7.4 The assumed mole fraction of hydrocarbons (YHC) is defined as a constant in the air-to-fuel ratio calculations in Method 28A. The mole fraction of hydrocarbons in the vapor phase will vary significantly with fuel and combustion conditions. Should hydrocarbon vapors (more appropriately, organic compound vapors) be measured as part of the method?

4. EPA Methods 5G and 5H correlations.

8.1 The comparison data to demonstrate the correlation between 5G and 5H are limited. Should the correlation between the two methods be reevaluated?

5. Performance deterioration of EPA-certified wood stoves in the field.
1. 9.1  It is the opinion of many in the wood stove industry that catalysts last only five years and that a stove designed for a catalyst operated without a functioning catalyst can produce as much emissions as a conventional stove. — Comments?
2. 9.2  Field studies in Glens Falls, NY, Medford, OR, Klamath Falls, OR and Crested Butte, CO showed that emissions from some catalytic stoves became appreciably worse even after two to three years of use. Inspection of stoves in Glens Falls showed that catalyst deterioration and leaky bypass systems were responsible. Have improvements been made in the design of catalytic stoves to minimize these problems? Is it reasonable to require homeowner training on the proper use of catalytic stoves and/or to incorporate into their costs an inspection and catalyst replacement program?
6. Stress test pros and cons.
1. 10.1  A short-term laboratory woodstove durability testing protocol was developed to predict the long-term durability of stoves under conditions characteristic of in- home use (see EPA-600/R-94-193). It was concluded in that study that damage occurs during those occasional times when a woodstove is operated in the home at exceptionally high temperatures. The laboratory stress test was designed to operate a woodstove at very high temperatures over a one to two week period to predict long-term durability under in-home use. Is this a reasonable approach?
2. 10.2  Should a stress test be made part of the certification process?
7. Feasibility of developing separate emission factors for dry and wet wood and for

softwood and hardwood species classes.

1. 11.1  Optimum wood moisture for low particulate emissions seems to be in the 18% to 20% range. Are you aware of any data that will allow the impact of wood moisture to be isolated from other variables? Could it be different for wood from different tree species?
2. 11.2  Wood from different tree species clearly burns differently. The chemical make-up and density of wood from different tree species is different. For example wood from coniferous trees has more resin than wood from deciduous trees. It is believed that particulate emission factors will be different for wood from different tree species. If this is true different parts of the country may have different emissions factors for residential wood combustion. Are you aware of any data that document different emission factors for wood from different tree species?

8. Routine maintenance.

12.1 Would routine maintenance of stoves once they were in a home reduce particulate emissions? Would this be more relevant for catalytic stoves than non-catalytic stoves? Would this be relevant for pellet stoves with electronic and moving parts?

2. 12.2  Should the home owner be provided with a maintenance manual or a training course at the time of purchase? Should a maintenance program be part of the purchase price particularly for catalytic stoves?
3. 12.3  What would the key elements of routine maintenance be?

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