Friday, November 20, 2020

Alaska releases deficiency details on wood and pellet stove test reports

Bryce Ward, Mayor of Fairbanks
North Star Borough.
Alaska posted summary review sheets of nearly every certified wood and pellet stove, exposing issues in a certification system that has been running for decades with little oversight. Of the 131 wood stove models, 130 had major problems in their testing report based on the Alaska classification system.

ADEC is pursuing EPA approval of s smoke reduction plan similar to one in Montana. They said, “Missoula City-County Montana regulations allows installation permits only for pellet stoves emitting no more than 1.0 gm/hr.  Alaska embarked on the certification test review and the establishment of a 1-hr filter pull standard as an alternative to a pellet only program for the nonattainment area as DEC feels this approach meets the communities desire for more device options and is at least equal to the Missoula requirement."  Click here for the full email.)

Alaska also sought and received approval from the EPA for an IDC cordwood stove test method to be "broadly applicable" which means any manufacturer can choose to use it in a stove's certification test. It also sets the stage for Alaska to potentially require that test for stoves sold in Fairbanks.

Alaska is undertaking this unprecedented review in an effort to find the stoves that they can be assured are the cleanest and meet all the requirements in EPA regulations under the Clean Air Act. AGH first covered this in a October 22 blog. In addition to checking that stoves meet the extremely detailed level of documentation based on emission testing, Alaska has imposed even stricter emission requirements, which do not apply anywhere other than Fairbanks. The primary stricter standard is that stoves cannot emit more than 6 grams an hour of particulates during the first hour of a multi hour test. Ultimately, when averaging the PM of the entire test, stoves must emit no more than 2 grams an hour to meet the Fairbanks standard, even though the federal standard allows up to 2.5 grams of PM if a stove is tested with cordwood.

Part of ADECs summary sheet showing
 the preliminary and initial final
determination and the reasons.
The initiative is being undertaken by the Alaska Department of Environmental Conservation (ADEC). It only impacts which stoves and boilers can be installed in a relatively small area around the city of Fairbanks that currently fails federal air quality limits. That is a very small market for the wood stove industry but the initiative may end up having far reaching implications for the EPA, the stove industry and how stoves are tested in the future.


One reason why so many stove models are flagged with multiple deficiencies is simply because ADEC officials missed data in the test reports or the manufacturer of the model has not yet provided it. Of the 130 stoves with major problems, many will likely meet Alaska’s review in the coming months. Manufacturers who have requested an extension from the State have until April 1 to work with Alaska to provide details, and only after that can the model not be sold in the Fairbanks non-attainment area. In the meantime, the review appears to shpow that only one wood stove model – MF Fire’s Nova tested by ClearStak lab – could be on the market. The data sheets on all stove models can be found here and will be updated at least monthly.

A Step 1 Jotul stove being tested by
Dirigo labs, taken over by PFS-Teco.
The data on pellet stoves is far better in some respects. Rarely do pellet stoves emit more than 6 grams during the first hour of a test like many wood stoves do. Of the 97 certified pellet stoves, only 3, or about 3%, are disqualified for this reason, compared to 31% of wood stoves. However, like wood stoves, the vast majority of pellet stove test reports had missing data. Only 7 had minor issues. As with wood stoves, over the ensuing months, scores more will likely be approved after missing information is found or provided by the manufacturer. Eleven of the test reports could not be found by ADEC. Sometimes links to these reports are hard to find, sometimes the link is broken, and sometimes the report doesn’t appear to be posted.

ADEC has not yet determined which missing items on test lab reports disqualify a stove. Some of the issues ADEC is flagging have to do more with paperwork requirements than the potential cleanliness of the stove. They are engaging in a series of meetings with EPA personnel from both enforcement (OECA) and air quality (OAQPS) offices to determine what is actually required by the NSPS, what isn’t required, and what should be considered significant. One long time technician at an EPA approved lab said that “based upon ADEC’s interpretation of the language in parts of the Federal Register, they have come up with several new requirements” which never existed before.

A 2019 pie chart made by AGH
showing an approximate percent
of stoves tested by each lab based 
on one data set.

For manufacturers, a key distinction is also data that was collected and exists, but was never calculated or reported properly, compared to data that was mistakenly not collected and could only be obtained by retesting the unit. It’s unclear if any of the test reports are so deficient that the EPA would ever considering revoking a certificate.

The scrutiny of certification paperwork by labs by Alaska also comes on the heels of years of effort by the stove industry to prevent stricter emission standards and the possibility of stricter audits. States have become increasingly frustrated that the EPA is not enforcing their regulations governing wood stoves and boilers. While enforcement was explicitly curtailed under the Trump administration, under Obama and previous administrations, enforcement has been regarded as lax or sporadic. In particular, the EPA has never initiated an audit of a wood stove or boiler to determine if it can achieve the emission levels that it got on its initial certification test. There is also no documentation of the EPA denying certification of a stove or boiler based on inadequate lab reports. In addition, there are only a handful of documented cases when a stove or boiler has failed emission tests in a lab even though industry cites very high rates of variability in emissions during testing.

Some of these issues emerged in 2019 when the EPA released hundreds of documents that NESCAUM had requested in a Freedom of Information Act request. But very little has ever been written about the many complex and opaque issues in test labs other than a blog AGH posted in August 2019: Records reveal successes and challenges in laboratory wood heater testing. That article explored issues of conflicts of interest, compliance with testing regulations and suspension of certification tests, all of which are receiving are receiving more scrutiny by ADEC officials and their partner agencies.


An ASTM 3053 test at Omni lab in
May 2020 on a GHP Group stove. GHP
is a company that has not 
requested that ADEC review its stoves.

ADEC’s initiative is also intertwined with concerns about the ASTM E3053 cordwood method and lab tests that showed the method was lax and may have helped some stoves to achieve certification to the EPA’s stricter 2020 standards with few or no modifications to their design. A meeting between EPA and state officials and industry representatives in January of 2020 explored these concerns and ADEC presented their strategy at that time.

ADECs efforts to improve air quality in the Fairbanks non-attainment area go back at least 10 years, starting with traditional stove and boiler change-out programs and a variety of restrictions. But the tenacity of excessive wood smoke in America’s coldest city has frustrated residents and officials alike, leading to this latest effort to understand which stoves are actually cleaner than others. Fairbanks is also spearheading solutions for the other most obvious culprit: unseasoned wood. As of October 1, 2021, only seasoned firewood can be sold in the non-attainment area.

Registration for firewood retailers is
compulsory in Fairbanks and voluntary
in the rest of the state.

It is still too early to tell how much this latest initiative will lead to cleaner air in Fairbanks. There is little doubt that it will bring a new level of scrutiny and integrity to test reports submitted to the EPA, and help the EPA and state agencies better understand how to craft a federal reference method for testing stoves with cordwood.

Postscript: In March 2021, NESCAUM released a report that was largely based off of the reviews of certification reports done jointly by ADEC and NESCAUM.  The scathing report concluded that the EPA process of certifying stoves is "dysfunctional" and recommended a series of aggressive measures.  AGH's initial response that report can be found here.


  1. Could you update as to whether AK has reviewed wood boilers also?

    1. Hydronic heaters (a.k.a. wood boilers) that use cord wood fuel are not permitted to be installed in Fairbanks, so ADEC isn't reviewing those emission reports.