EPA releases long-awaited searchable wood heater database

A screen shot of part of the
navigation of different fuel types
in the new EPA database

Consumer friendly site is cause of worry for some

Updated Dec. 2020  - The EPA released its long-awaited searchable stove and central heater database, overhauling a decades-old practice of using basic excel sheet lists.  The database is now a very user friendly site for consumers and all stakeholders.  A simple search that could have taken hours, now takes seconds.

The EPA said the new database was designed to“improve accessibility and usefulness” by allowing users to search for the cleanest stoves, the most efficient stoves, those designed to burn cordwood and other attributes.

A wide range of stakeholders, from industry to states to non-profits, had been urging the EPA to switch to a modern searchable format for nearly a decade. The painfully slow development of the database at times seemed to epitomize the government's reputation to move at a snail’s pace. The list is maintained by the EPA’s Office of Enforcement, which like much of the EPA has been hit with repeated budget cuts and loss of staff in recent years.

The sleek new functionality of the list, allowing users to focus on one parameter or another, is also worrying to many in the stove industry. Traditionally, this list of certified wood heaters has not been a primary information source for consumers. But with this new functionality, consumers may start relying on it more and more, leading to some unintended results, such as worse buying decisions or ones that favor some manufacturers over others.  Similar to the feature in the old excel spreadsheets, the new database now also indicates new additions.

One fear is that consumers will put too much reliance on higher BTU output if they can easily search and cross reference by these values. Right-sizing a stove is already problematic, and the BTU values on the list are overinflated due to loose parameters that allow labs to show high BTU output. Another fear, expressed by some manufacturers at the recent HPBA Expo in Nashville, is that consumers will favor “Cord Wood” stoves over “Crib Wood” stoves because they are not familiar with the lexicon of stove testing and the legacy of crib wood. 

The EPA chose to include a box that helps consumers identify the cleanest and most efficient stoves,

and some say that this puts unwarranted attention to values that won’t necessarily translate from the lab to the home. This “Quick Searches” box will likely be used by consumers who don’t understand pellet stoves work similarly in the home as they do in the lab, but wood stoves can only achieve the optimal lab numbers with a large bed of coals, dry wood and careful operation.

This “certified fuel type” feature also sheds light on one the biggest problems with the new searchable data – accuracy. Six wood stoves were initially listed as using wood chips as a fuel, an apparent mistake according to one of the manufacturers of those stoves. As of November 2020, two stoves are still listed as being tested with wood chips, even though no such test method exists. This could hurt sales of those units if consumers are relying on the database to narrow down the stoves they may purchase. EPA staff are quick to say that this is a work in progress and it is incumbent on manufacturers to vet the list and provide the EPA with corrections. In 2017, the HPBA warned the EPA that many inaccuracies existed in the database. Many of the same errors are still listed two years later.  A whole new frontier of recognizing deficiencies is now being opened up by an Alaska initiative that is reviewing all certification documents.

The Alliance for Green Heat welcomes the new database and had the opportunity to provide input on several occasions as other stakeholders did. Some of our suggestions and wording was adopted and some was not. AGH believes that the new database will help consumers become more educated about the working of stoves and the terminology, but it will take time and effort by the wood heating community.  AGH is currently urging the EPA to add a column showing what test method was used to identify single burn rate stoves and stoves that used an alternative test method.

The release of the database was coordinated with the update of some key pages on the EPA's Burn Wise website. The EPA finally changed their page on hydronic heaters which previously defined and pictured them just as outdoor boilers, a change that AGH had urged them to make for years. They also made major changes to their efficiency page which had not been updated since the EPA began requiring testing and reporting of efficiency of stoves.

Features and functions

·      Pellet stoves

The database shows 98 out of the 242 models are pellet stoves.  Nearly half of the  pellet stove models are 1 gram or under.

·      Catalytic Stoves

The database shows that 30 of the 144 models are catalytic, and another 19 are hybrids which also use catalysts. 

·      Hybrid Stoves

Wood stoves are divided into three
subtypes - cat, non-cat and hybrid.

Hybrid stoves, which almost all use both catalysts and air tubes for secondary combustion, are listed as a subtype and  there are now 19 stoves listed as hybrid. AGH is urging the EPA to also add “automated stoves” as a subtype in the future. Both hybrid and automated stoves offer great promise to help consumers run stoves more cleanly.

·     Cord vs. Crib wood
                  As of Nov. 2020, 83 of the 144 wood stoves were tested with cord wood, indicating a surging popularity with the ASTM test method, that allows more flexibility in the lab.

      BTU Output

With tighter homes and a new breed of tiny homes, it is now easy to search for stoves with the lowest BTU output. Many models are tested at less than 25,000 BTU. AGH believes that many units still have erroneously high BTU values based on loose parameters in lab testing and reporting, and these values should be used with great caution. 

Firebox volume

The cubic size of the firebox is an equally useful tool to estimate BTU output.  They range from 0.5 to 4.4 cubic feet. AGH has concerns that some BTU output figures are exaggerated due to the allowable calculations that labs can use to estimate heat output.  Small fire boxes are usually considered to be up to 1.5 cubic feet and good for holding a fire for no more than 4-6 hours.  Medium fireboxes are in the 1.5 to 2.5 range and usually can hold heat for 6 - 9 hours and large fireboxes are 2.5 - 4.5 cubic feet and can easily hold heat overnight.

Test method

In December of 2020 the EPA added a column to designate the test method that was used to determine emissions, but they have not yet populated the column with any data. This will help better understand which are single rate burn stoves, for example, and which stoves got variances.  The detail will be too technical for the average consumer but useful for stove geeks and agencies.

·      Efficiency

The EPA has chosen to use the term “overall efficiency” instead of simply “efficiency.” Some manufactures use “optimal efficiency” or “maximum efficiency” instead of publishing the EPA tested efficiency, which is lower. One hundred out of 244 models tested at 75% HHV efficiency or greater.

·      Carbon monoxide

Like efficiency, carbon monoxide is required to be tested and publicly disclosed, but there is no regulated minimum or maximum that must be met.  The CO listing raised concern from some who worry that consumers may use it instead of PM as a primary indicator of cleanliness, or that consumers may think it’s an indication of amounts of CO emitted into the room.

· 

·       Previously certified

The database also shows the 205 stoves that were previously EPA certified at 4.6 grams or higher, a feature that could be very helpful for change out program managers who want to target older certified stoves, many of which need replacement.

·      Key terms and definitions

The EPA provides a new page with definitions of key terms such as adjustable burn rate vs. single burn rate heaters, fireplace insert, wood pellets, etc.

·      Central Heaters

The database is separated into two: “Room Heaters” and “Central Heaters” and you have to select one or the other or your search may turn up empty. There are 32 central heaters with 12 that use pellet fuel.  Of the 32 heaters, only 3 are forced air furnaces.

·
Not included in the new database

Some stakeholders have urged the EPA to include more search attributes, such as the test method, lab, and a link to the detailed lab report that manufacturers are required to post on their websites. The list also does not say whether PFI certified pellets were used during certification testing and are thus technically required to be used by the consumer.  Up until 2007, the list used to include the deadline that the five year certification certificate expired.  Up until the summer of 2015, the list included the outmoded estimated default efficiencies, which listed all non-cats at 63%, cats at 72% and pellet stoves at 78%.  The default efficiencies were set based on testing in the mid and late 1980s, resulting in relative accurate estimates for wood stoves, but helping to develop the enduring myth that pellet stoves had such high average efficiencies.

Contact Rafael Sanchez at the EPA's Office of Enforcement to address errors or omissions in the database, (sanchez.rafael@epa.gov) at (202) 564-7028.

Study of pellet stoves shows environmental advantages - and corporate exaggerations

An independent assessment of popular pellet stoves conducted by the Alliance for Green Heat  found that pellet stoves, unlike most wood stoves, can achieve low levels of emissions in real world settings that are in line with laboratory results.   

The Alliance for Green Heat ran a battery of tests on popular pellet stoves designed to approximate how they would perform in the real world.  The group found that half of the stoves operated as clean at the end of the thirty-day test than they did at the beginning and the others were only slightly dirtier.

All six stoves, from the least to the most expensive, operated well, and produced enough heat for a small to medium- sized home in most of the United States.  One of the biggest differences was that the three more expensive stoves tested (above $4,000) needed very little weekly cleaning and maintenance.  The less expensive stoves ($1,200 to $3,300) needed daily or at least bi-weekly cleaning of their burn pots and glass.

The study also found a lack of accepted reporting standards, leading to exaggerated claims about efficiency, BTU output and pellet hopper size on manufacturer websites and promotional literature. 

The Alliance for Green Heat tested the stoves to give consumers better tools and make better purchasing decisions.  The study is part of a yearlong Pellet Stove Design Challenge that assesses the state of existing pellet stove technologies.  The Design Challenge will culminate in a competition for the cleanest and most efficient stoves, modeled after the Department of Energy’s Solar Decathlon.

Approximately one million American homes are heated with pellet stoves, more than twice the number that have solar panels.  In Italy alone, 2 million households heat with pellets. Pellet stoves often serve as primary heat sources, enabling homes to eliminate or drastically reduce fossil heating fuel.  Last year, about 40,000 pellet stoves were sold in the U.S. and they may outsell wood stoves in the near future.

The Alliance tested the England Stove Works 25-PDCVC, the Enviro M55 insert, the Harman Accentra 52i insert, the Piazzetta Sabrina, the Quadra-Fire Mt. Vernon AE, and the Ravelli RV80.  The group assessed each stove on its cleanliness, efficiency, maintenance, heat output and visibility of glass.  The overall winner was the Quadra-Fire Mt. Vernon AE, which received top marks in three of the five categories.  The Harman Accentra received top marks in two of the five categories.

The results of this study underscore that pellet stoves tend to burn substantially cleaner than wood stoves in real world settings, but it challenges the notion that pellet stoves generally have higher efficiencies than wood stoves.  The efficiencies of the six stoves were low to medium, which is partially the result of companies not having to test and report actual efficiency numbers. 

“Our testing confirmed that pellet stoves are an effective and affordable renewable energy technology,” said John Ackerly, President of the Alliance for Green Heat. “We hoped to see higher efficiencies, but efficiencies should improve in coming years,” Ackerly added.

Click here to read the full report on our website.
Click here to download a PDF of the report (the PDF does not have all the links and photos that the online version has).
Click here to download a PDF of the background materials to the report.

The Alliance for Green Heat promotes modern wood and pellet heat as a low-carbon, sustainable and affordable residential energy solution. The Alliance works to advance cleaner and more efficient wood heating appliances and focuses on low and middle-income families.  Founded in 2009, the Alliance is a 510(c)(3) non-profit organization based in Maryland.