Posted by Earth Stove on January 12, 2016 with No Comments
The Internet is full of opinions and reviews of wood pellet brands. However, data of actual properties of various wood pellet brands is hard to locate. It cost under $ 100 for a lab to test ash, moisture and BTU content of a pellet. We tested 4 popular brands, along with corn kernels, to see the variability between brands. Our overall conclusion: much less variability than we expected (except for the corn).
Conventional wisdom is that you should buy a couple bags of pellets to see how they work on yourstove before buying a ton or more. That’s good advice, as some stoves handle a much wider range of pellets, while others do not. It’s especially good advice in light of the lab testing we did, that shows little variation between moisture, ash and BTU content of four popular brands.
The four brands we bought – made by American Wood Fiber, Curran, Pennington’s, and Nation’s Choice – are all major brands but only represent a small fraction of available brands. Two of them are PFI certified, which means that they must meet certain quality guarantees and cannot have more than 1.0% ash, 8.0% moisture, and 0.5% fines, among various other requirements. All four brands of pellets we tested fell within the parameters required by PFI premium grade, for the criteria that we tested – ash and moisture. We did not test for fines or for durability or bulk density or chlorides – things that can be important for performance. The cost for testing those qualities is about $ 250, more than we wanted to spend for each test.
Pellet manufacturers, whether they are PFI certified or not, usually do not disclose actual BTU, ash or fines, but just say that they do not exceed a certain level.
Ash content: Ash is one of the biggest concerns of consumers since high ash pellets can clog up some stoves and require more cleaning. Of the four brands we tested, the ash content was relatively similar, ranging from about 0.3% to 0.6%, far below the acceptable level under the PFI certified standard of 1.0%.
Whether your stove is 60% efficient or 80% efficient, you will get more heat from a pellet with more BTUs. Some pellet brands may have up to 8,800 BTUs per pound and some only 8,000. Still, only a 9% difference, would be $ 250 a ton and $ 272 a ton. The higher BTU pellets we tested had 8,439 BTUs per pound, 5% more than the lowest BTU brand, which had 8,011.
Moisture content varied even less than ash and BTU content between the four brands we tested. The low was 5.1% and the high was 5.8%. PFI allows up to 8%.
Price on all these 4 brands can vary depending on the time of year, the location, the seller, and whether or not a ton is purchased. Pennington’s, Nation’s Choice, and Curran have all been available at big box outlets in the $ 250/ton range over the past several months. The American Wood Fiber Ultra Premium White Pine is more expensive, as 100% softwood pellets tend to be, especially on the east coast.
Options for future testing
Testing and publishing the BTU, moisture and ash content of dozens of common wood pellet brands would be a great resource for consumers. Please let us know if you agree or have suggestions about how to develop and maintain a reliable, independent data base of pellet characteristics.
This report and the pellet testing was supported in part by a grant from the Maryland-based Rouse Charitable Foundation.
Posted by Earth Stove on December 19, 2015 with No Comments
|Labs test wood and pellet heaters for
efficiency and ones that are 75%
efficiency or higher can qualify
for the $ 300 tax credit.
The United States Congress is on the verge on finalizing a massive omnibus spending bill that would fund the government and provide tax breaks to businesses and individuals. Among them is the $ 300 tax credit to purchase a wood heating appliance. The bill extends that credit through Dec. 31, 2016 and is retroactive to Jan. 1, 2015.
In a far more widely anticipated move, Congress is poised to extend the 30% tax credit for residential solar panels through 2019 and then gradually reduce it. This credit was set to expire at the end of 2016 and offers that industry a level of support and certainty for strong growth.
For wood and pellet heaters, the bill extends the $ 300 tax credit, contained in Section 25C of the IRS tax code, which states taxpayers are entitled to a $ 300 tax credit for the purchase of a wood or pellet heating appliance that is 75% efficient or greater. Consumers need to obtain a certificate from the manufacturer, stating that the appliance is qualified for the credit.
For consumers who purchased a wood or pellet stove in 2015, or who will do so in 2016, they will likely be entitled to the $ 300 credit if they have not used up their $ 500 lifetime maximum credit for energy efficient property.
For wood, pellet stove, and boiler manufacturers, the process of issuing a certificate claiming their appliance is 75% efficient may be more complicated than in the past. In previous years, manufacturers claimed that every single stove they made was at least 75% efficient, flouting the letter and intent of the law, which was to only qualify stoves at 75% efficiency or higher, measured by the lower heating value (LHV). As of May 15, 2015 all stoves and boilers certified in the US are tested for efficiency using the CSA B415.1-10 efficiency test. This efficiency test provides a guideline for how to test and not all stoves will achieve an efficiency of 75%.
“Higher efficiency wood and pellet heaters deserve renewable energy incentives to help American families reduce reliance on fossil fuels and to encourage companies to build higher efficiency appliances,” said John Ackerly, President of the Alliance for Green Heat, an organization that advocates for wood and pellet heating. “In the past, some in industry has made a mockery of this tax credit, misleading tens of thousands of consumers into thinking they are buying higher efficiency stoves. Its time to start measuring efficiency and reporting it honestly and only qualifying those heaters that are 75% efficient or higher, using the lower heating value,” Ackerly said.
The Alliance for Green Heat estimates that up to half of all wood and pellet stoves and boilers could meet the 75% efficiency threshold, giving consumers a wide range of choices. Appliances that are 75% efficient using the European lower heater value (LHV) are usually between 69 – 71% efficient using the North American higher heating value (HHV).
A leading industry expert, Rick Curkeet concluded in a 2008 letter to an industry trade association
that “the intent of the solid fuel appliance incentive program recently enacted by Congress is … to require a minimum of 69.8% efficiency.”
Stove manufacturers do not have to publicly disclose their efficiencies and very few of them doA few stove companies, such as Blaze King, Jotul, Kuma, Seraph, Travis, Woodstock Soapstone publicly disclose actual efficiencies of most of their models on the EPA website and almost all of those models appear to qualify for the tax credit. The EPA considers higher heating value as a more accurate measure of efficiency for devices in the U.S. and therefore uses only those number on its list of EPA certified wood and pellet stoves.
Unlike other heating and cooling appliances, prior to May 2015 wood and pellet heating appliances did not have to test or report efficiencies and there are still few accepted norms on advertising practices. Websites and promotional materials of many major stove brands contain exaggerated efficiency claims, some of which may come from the company’s internal laboratory, not from a reputable, third party lab.
Posted by Earth Stove on December 9, 2015 with No Comments
|29 Republican House members
sponsored the bill to repeal the new
EPA heater regulations
An energy bill passed the House of Representatives with an amendment that repeals the EPA’s new residential wood heater regulations. The bill is not likely to pass the Senate and President Obama vowed to veto it, if it comes to his desk.
The passage of a bill that includes repealing the EPA’s residential wood heater regulations came as a surprise to most in the hearth industry, as well as in relevant state and federal agencies.
The bill, the North American Energy Security and Infrastructure Act of 2015, H.R. 8, was passed the House of December 3 with 240 Republican votes and 9 democrats. In addition to core issues in bill, it repealed more than 20 energy and energy efficiency studies and programs, including the EPA’s wood heater regulations which “shall have no force or effect and shall be treated as if such rule had never been issued.”
The underlying bill, H.R. 1986
, dubbed “the Stop EPA Overregulation of Rural Americans,” had 29 Republicans and no Democrat co-sponsors. The sponsors of the bill are almost all from very rural parts of the country but members of Congress representing districts with the highest levels of wood heating did not co-sponsor the bill. Most of the sponsors come from the southern half of the United States and likely reflect their deep-seated opposition to the EPA regulations generally.
Some of the sponsors of the bill refer to a “War on Rural America.” One of the most vocal advocates for the bill, Congressman Jason Smith (R-MO-8) repeatedly says the EPA is regulating existing stoves, not just new ones. He said in a statement that there are 12 million stoves in 2.4 million homes, probably referring to the distinction between the estimated total of 12 million stoves and the 2.4 million homes that use wood or pellets as a primary heating source.
None of the industry groups representing sectors of the hearth industry, including Hearth, Patio & Barbecue Association (HPBA), Biomass Thermal Energy Council (BTEC), and Pellet Fuels Institute (PFI), supported H.R. 1986, and it is unclear if any major company in the hearth industry supported the bill. One small Michigan company, Eco-Fab Industries that makes Eco-Maxx outdoor wood stoves which do not meet EPA emission regulations and cannot be sold in the residential market after Jan. 1, 2016, supports the bill.
Hearth industry leaders indicate that they are vested in broad parts of the NSPS and think that a judicial challenge to certain parts is the best strategy for the solution they want.
HPBA had mounted a legislative push in 2014, urging members of Congress to sponsor H.R. 4407that would have prohibited the EPA from setting emission regulations lower than 4.5 grams per hour. Some of the members who supported H.R. 4407 became co-sponsors of H.R. 1986.
“Thousands of hard working industry, non-profit and agency officials put years of work into these regulations and they are truly a compromise of competing interests,” said John Ackerly, President of the Alliance for Green Heat. “If no major stakeholder group is supporting the repeal of the regulations, why is the House of Representatives voting to do that?” Ackerly added.
Posted by Earth Stove on November 16, 2015 with No Comments
The EPA issued its long-awaited voluntary hangtag, which will help consumers identify the cleanest burning wood and pellet heaters on the market. Only manufacturers who make stoves and boilers that already meet the stricter 2020 emissions standards can use the hangtag.
The hangtag is a major step towards a “green” or “eco-label” for wood and pellet stoves for designating those stoves that emitted the least amount of smoke in the test lab. The hangtag has a line to record efficiency, if the manufacturer chooses to disclose it, but disclosing efficiency is not required. The Alliance expects some stoves with higher efficiencies to list their efficiency on the hangtag, and stoves with lower efficiency numbers to not disclose their efficiency.
Most European countries have had eco-labels specific to stoves for many years that have helped drive the market to exceed the minimum emission and efficiency standards. The EPA designed this hangtag “to provide an incentive to manufacturers to meet the federal 2020 standards early” but the main industry stove association, the Hearth, Patio & Barbecue Association (HPBA) is suing the EPA to prevent those stricter 2020 standards from taking effect. It is still too early to tell if the big stove manufacturers may decline to use the hangtag because they may view it as a step toward the 2020 standards. Some smaller companies, that are not members of the HPBA, are already taking steps to display the hangtag.
The current emission standard for wood and pellet stoves is 4.5 grams per hour and the more stringent 2020 standard will be 2.0 grams per hour. There are 76 models of pellet stoves on the EPA’s list of certified stoves and 48 of them are already under the 2 grams per hour limit, so 63% of pellet stove models already meet these 2020 standards and are eligible to display the consumer hangtag. Eleven stoves, or 14% of all pellet stoves are already less than 1 gram per hour.
More than 2-dozen non-catalytic stoves and more than 2-dozen catalytic stoves are eligible to use the hangtag. (Unlike pellet stoves, the emissions from wood stoves are not designed to estimate emissions from in-home use and homeowners will typically emit far more smoke than labs can achieve during a certification test.)
Among EPA certified wood and pellet boilers, there are 72 models on the market and 38 of them meet the 2020 emissions standards and can use the hangtag. Of those 38, only 5 of the models use cord wood achieve the 2020 standards but virtually all of the pellet units (33 out of 35) achieve the 2020 standards. Most of the certified pellet boilers are technologies imported from Europe and emit about one tenth of the emissions that certified cord wood boilers emit.
The development of the hangtag posed a number of concerns for the EPA, including whether they should list heat output in BTUs per hour, which is already included on the EPA’s list of certified stoves. The EPA decided to use a more general estimate of heat output, “Heating Area” in square feet,
estimated by the companies themselves, because BTU per hour claims have become too unreliable and prone to exaggeration. In the past, the EPA did not require that test labs use actual efficiency numbers in heat output calculations, allowing test labs to use a range of efficiency estimates to make stoves look far more powerful that they actually are.
The hangtag also provides a box for companies to designate if they test with cordwood. So, for the first time ever, consumers can start to identify stoves that are designed and tested with the fuel that they would typically use themselves. No stove has been certified with cordwood yet and the ASTM cordwood test method is still in progress, but several companies are expected to test with cordwood in coming months.
The EPA is using the back of the hangtag to list important educational messages. Among those messages is the strongest endorsement yet of certified pellets, a move that will irritate many pellet manufacturers who have been resisting getting their pellets certified. The EPA went so far as to claim that “non-certified pellets may be high in ash content, low and energy output, and have impurities that could harm your families health.” While some cheaper pellets have high ash content, low heat output and possibly even contain impurities, the quality of many uncertified pellet brands are on par with those that are certified and some of the highest quality pellets are not certified.
The EPA’s willingness to strongly endorse pellet certification comes at a time when the main certifying body, the Pellet Fuel Institute (PFI), is also suing the EPA over some of the finer points of requirements that the EPA puts on pellet certification.
The success of the EPA’s consumer hangtag, like many eco labels, may hinge on branding and how recognizable the hangtag is to consumers. If the EPA, states, and non-profits put resources into promoting the hangtag, consumers will be more likely to ask for it and base their purchasing decisions on it. The first companies to start using the hangtag could see a boost in their sales and it could put pressure on the mainstream companies to use the hangtag, if they aren’t already.
“This hangtag will help consumers not only choose cleaner stoves, but also to choose companies committed to making cleaner stoves,” said John Ackerly, President of the Alliance for Green Heat. “If the stove you buy today already meets the 2020 standards, the parts and service for that stove are more likely to be available 5-10 years from now, when you need it,” Ackerly added.
# # #
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.
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.
On October 6, the US government agency responsible for tracking energy supply and usage released its annual winter fuels outlook. The report predicted that next winter will be warmer than average but energy prices will be lower. Consequently, consumers are expected to pay 10 – 20% less on their household heating than last winter.
The report notes that the use of cord wood and wood pellets as the primary residential space heating fuel has increased by 33% since 2005 and estimates that about 2.6 million households mainly used this fuel source in 2014. About 8% of households use wood as a secondary source of heat, making wood second only to electricity as a supplemental heating fuel.
The report, produced by the Energy Information Agency (EIA), projects primary wood and pellet heating to grow by 1.4% during the 2015-2016 winter. Electric heating is projected to rise even faster, by 2.5%.
Natural gas is projected to remain basically flat, and oil and propane heating are projected to decline by 4.4% and 3.4%, respectively.
The overall national residential wood heat rise of 1.4% includes quicker projected growth in the Northeast and a slight decline in the West.
Wood and pellet heating is projected to rise fastest in the Northeast at 2.8% and the South at 2.6%. It’s only projected to rise 0.8% in the Midwest and decline by 0.3% in Western states.
In 2014, the Pellet Fuels Institute reported that shipments of pellet stoves grew by 41%. On average, 2 out of every 5 new stoves sold is a pellet stove and 3 are wood stoves. This ratio does not include the popular, though polluting, uncertified wood stoves that are still on the market until the end of this year.
“The trend towards more pellet heating is crucial as wood heat expands in America,” said John Ackerly, President of the Alliance for Green Heat. “The growth in pellet heating, even as oil and gas prices fall, show a demand for a cleaner, local fuel that still can be greatly scaled up,” Ackerly said.
Wood heating was increasing faster than electric heating for many years, but since 2008, wood has increased by nearly 10% and electricity increased by nearly 15%.
In terms of the amount of energy generated by residential renewables, wood continues to be the dominant player, generating 66% of all residential renewable energy in 2014. Solar produced less than half the energy as wood and pellet stoves, making up 29% of residential renewable energy in 2014. Geothermal produced nearly 5%.
However, solar will soon be catching up to wood according to EIA projections, thanks to extensive state and federal subsidies.
In 2016, the EIA projects that wood and pellet stoves will only produce 54% of residential renewable energy and solar will produce 40%.
Geothermal is projected to rise to nearly 6%.
The EIA did not include data or projections on wood and pellet hearing until their 2012 report
. Senator Shaheen (D-NH), the Alliance for Green Heat, and other groups pressed the agency to be more inclusive of the technology that was used by more households than oil or propane. Since then, the EIA has gone much further and is about to start surveying wood pellet producers to provide accurate and timely data about pellet production and usage.
Posted by Earth Stove on September 3, 2015 with No Comments
About 2,000 Quadra-Fire Mt. Vernon E2 pellet stoves and inserts are being recalled and repaired, due to high pressure that can lead to explosions that shatter the glass in the door. The company says the stove is safe if properly operated. The Consumer Product Safety Commission issued a voluntary recall on July 9, 2015. Problems were first reported to the company by consumers in the winter of 2015.
The problem is unique to this model and does not present a safety issue in other models sold by Quadrafire or any other manufacturer, according to pellet stove experts. If you own a Mt. Vernon, follow instructions in the voluntary recall notice and the company will repair the stove free of charge.
Some consumers and stove retailers contend that the stove was poorly designed and even if a stove is not operated properly, it should not build up pressures that can lead to explosions. At least 6 stoves have malfunctioned, leading to glass in the front door shattering, sometimes sending flying glass through rooms. No injuries have been reported. AGH believes the EPA should ask that this stove be re-certified since changes to it are substantial.
A number of discussions in independent chat rooms have raised the issues and include commentaries by affected consumers about how Quadra-Fire has responded.
The Alliance wrote to HHT asking for clarifications about what caused the malfunction and whether the stove would be 3rd party tested again for safety. We formally asked for information for our newsletter, which may have led to a less responsive reply, which is reproduced below.
———- Forwarded message ———-
From: Mathis, Kristen (HHT)
Date: Tue, Aug 4, 2015 at 11:34 AM
Subject: RE: questions about the Mt Vernon E2 for wood heat newsletter
To: John Ackerly
I wanted to send these responses as promised, although I see the newsletter has already gone out. The responses below in RED
are provided by our VP Product Engineering, Gregg Achman.
1. Will HHT be sending this stove back to any 3rd party lab for safety testing?
When a modification is made to a Hearth & Home Technologies product, all necessary certification bodies are informed and the required testing is completed. Updates and notifications are published as necessary, and in accordance with the respective entities.
2. In your certification testing with OMNI, did any of the tests involve running the stove as the consumer might do it, instead of following the owner’s manual?
OMNI follows the testing protocols set forth in the test standard that the appliance is being certified to. The test standards follow ANSI protocol, and go through a revision process that allows for review and comment from interested parties to address future requirements and enhancements for performance and safety.
3. From your website and from talking to various HHT dealers, its confusing as to whether you consider this mainly a problem with incorrect operation by consumers, or whether its a flaw in the stove operating system. Your site says that the stoves in question will receive an enhanced control board “if necessary.” Are there some stoves that are not getting an enhanced control board or do all stoves in the recall get the enhanced control board?
HHT issued this recall proactively and in conjunction with the CPSC to reinforce our commitment to consumer safety. No injuries related to the Mt. Vernon E2 stove or insert have been reported. Issues of glass breakage are only related to Mt. Vernon E2 stoves and inserts when not maintained as outlined in the owner’s manual.
This recall affects an isolated set of units; if the unit is verified to be within the select group of recalled stoves or inserts, the control board should be replaced. HHT dealers have proactively contacted all consumers with affected stoves to have them repaired.
Lastly, you mention being unable to connect with someone at HHT. While I can’t speak to previous relationships, I do want to open the door for you to connect with me when you have questions moving forward. We always appreciate the opportunity to share factual information about our products and/or to share our passion and enthusiasm for the industry, and I can typically turn around responses in 2-3 business days.
Sr. Communications Manager
The 2014 Winter Fuel Outlook released by the US Energy Information Agency on Oct. 7, predicted that wood and pellet heating would continue the trend of being the nation’s fasting growing heat source. Overall, wood and pellet heating grew 38% from 2004 to 2013, and now accounts for 2.5% of all home primary heating.
The EIA predicts wood and pellet heating will grow again in the 2014/15 winter by 4.7%. Electricity is predicted to grow second fastest at 3.1%. Natural gas is at .07% growth and oil and propane are each predicted to drop by about 3.2%. Regional data shows wood and pellet heating growing more than 7% in the northeast and Midwest, and only 2.5% in the south and 1.8% in the west. It was only two years ago that the EIA started to include wood and pellets in the 2012 Winter Fuel Outlook, even though far more homes have wood and pellet stoves than have oil furnaces.
Nationally, solar and geothermal dominate headlines and media imagery, but wood and pellet heating remain the dominant players in reducing fossil fuel usage at the residential level. In 2014, the EIA says wood and pellet heat will produce .58 quadrillion Btu, or 67% of the nation’s total, while residential solar will produce .25 quadrillion Btu, or 29%. Meanwhile, geothermal produces only .04, or 4%, and is not showing steady increases like solar.
While wood and pellets are the fastest growing heating fuel in America, residential solar is growing even faster in the electricity marketplace. At current rates, residential solar could produce more energy than residential wood and pellet stoves by 2020. Solar has enjoyed generous taxpayer subsidies with a 30% federal tax credit in addition to state incentives. The federal solar credit is set to expire at the end of 2016, but by then the cost of solar panels may have decreased enough for continued growth without federal subsidies.
Wood and pellet heating and solar are not competing technologies in that one produces electricity and the other heat. They are often combined to make a home virtually carbon neutral, a process which is moving far faster in Europe than in the US due to higher fossil fuel prices and favorable government policies.
In Europe, many countries are aggressively incentivizing higher efficiency pellet stoves and pellet boilers. In the US, the Bush and Obama Administrations did not push for incentives for cleaner and more efficient pellet equipment but rather has let Congress and industry shape a tax credit without any effective efficiency or emission criteria. As a result, the 38% growth of wood and pellet heating since 2004 documented by the EIA is not predominantly an expansion of cleaner and more efficient equipment, as it is in Europe. Sales of cleaner pellet stoves are rising in the US, but the growth of wood heating in America includes some very polluting equipment such as outdoor wood boilers, also knows as outdoor hydronic heaters and new unregulated wood stoves, neither of which have emissions standards. After many years of delays, the EPA is finally regulating these technologies and requiring them to meet emission standards by summer of 2015.
Without effective federal regulations from the EPA, some states have been guiding the market toward cleaner and more efficient wood and pellet heating equipment, with Maine, Maryland, Massachusetts, New Hampshire, New York, Oregon and Washington taking the lead.
This year there are at least half a dozen stoves on the market that have some automated feature that didn’t exist on the market a few years ago. Many of these features help the stove burn somewhat cleaner, and are aiming at a demographic looking for easier operation. It’s still too early to tell how well the automated features work, compared to what they claim to do.
To truly understand the benefits of automation features, whether it be the traditional bi-metal coil or up-and-coming electronic sensors and on-board computers, you need to have side-by-side tests with the automation on and off. Easier said than done. In Europe fully automated stoves – meaning stoves that you can “load and leave” – and the operator has no or limited control to adjust heat output, are already on the market. None are on the market in the US as there is no test method to certify them. The regulatory barrier to potentially far cleaner stoves from entering the US market is being addressed at the Collaborative Stove Design Challenge
, where a automated stove testing protocol will be developed and submitted to the EPA.
Three major players in the US stove manufacturing community – Quadrafire, Travis and England Stove Works – now have automated systems to reduce start up and reloading emissions, which is one of the most important emissions issues that needs to be addressed. The Travis system uses electricity and is likely the most powerful of the three, and the other two don’t need electricity. The England Stove Works stove has integrated their innovation in a very affordably price stove.
The real promise of automation is not to get a hot stove to hit an ultra-low particulate matter number in a lab, but to improve real-world performance by seamlessly optimizing performance throughout the burn cycle, to reducing start-up emissions and reducing emissions from unseasoned wood. EPA certification testing does not attempt to test these attributes of a stove, so stove companies have not had much incentive to invest a lot of time, effort and money to design for that.
In the United Kingdom solid burning heating devices are not classified by their size, i.e. stove vs. boiler, but by whether they are automatic or manual. To achieve a rating to be used in more polluted areas, manually operated stoves must submit lab tests showing 5 burns for each output level because “manually controlled appliances show much higher variation between tests.” Automatic appliances only have to be tested 3 times at each output level.
The chart below shows a wide variety of technology that exists in both stoves and boilers in Europe, but only exists in boilers in the U.S., and much of it is imported from Europe. (Click here for PDF that includes this chart and some discussion of these issues.)
In November 2014, Brookhaven Lab will be testing automated stoves and prototypes at a stove design workshop to see how effective they are. Their designers aspire to be part of a real trend of cleaner, more automated residential wood heating. But can they do it at an affordable price point? And, are consumers ready for them? Here, we will look at stoves with automated features that are already on the market.
|A bi-metal coil acts as a heat-
sensitive thermostat which can partially
control the opening and closing of the damper.
1. The bi-metal coil. The oldest form of automation of steel wood stoves is the bi-metal coil which has been used on scores of stove models and is now mostly just used by a few catalytic stove makers, principally Blaze King and Vermont Castings. Some of the new automated features do something similar as the bi-metallic coil, but potentially do it much better. A bi-metal coil is simply a thermostat run by a metal coil that can close a damper down when its really hot, and open it up when its cooler. The stove’s air inlet can still be operated manually, but the bimetal coil will adjust the air inlet further. They tend to not work nearly as well on non-cat stoves, because the temperatures in a non-cat firebox can be more unpredictable, and if the coil shut down the air, or opened it too much, the stove would operate poorly – and critically – it adds far too much uncertainty in passing the EPA emissions certification test.
|The rotating trigger mechanism in the
Smartstove Collection by Englander
reduces air flow once the stove is hot.
2. The next three stoves – the England Smartstove, the Quadrafire and the Travis – all use different automated approaches to starting the fire quicker and with fewer emissions. After the start-up period, the stove operates like any other. The Smartstove by England Stove Works was displayed at the Wood Stove Decathlon on the National Mall in 2013, but it was still being certified by the EPA so it was not part of the competition. The stove has an “automatic air setback mechanism” which is a primary air control with a rotating trigger which controls the opening and closing of air vents. When the operator starts a fire, they gives the stove maximum air and sets the trigger. When the stove gets hot enough, the trigger releases and primary air is reduced, while still providing ample secondary air.
|Quadrafire’s Explorer 2 Start-Up air
control helps give the stove more
air in the first 25 minutes.
3. Another recent arrival on the market is Quadrafire’s Explorer II, which appears to provide similar automation. The website says “Automatic Combustion Control-provides the fire with air when it is most needed-leading to longer burns.” A marketing video says the operation is so easy that all you have to do is “load the wood, light the fire and walk away.” According to the installation manual, ACC is basically a timer which the operator must manually initiate with a control mechanism. Essentially, it opens the front air channel which allows air to enter for 25 minutes before closing. Once the front air channel is closed, manual controls are used to deliver preheated air to the top of the firebox to burn the rest of the unburned gases in the remaining three combustion zones.The Alliance confirmed with a company representative that no sensors are used or needed after the operator sets the timed control mechanism.
|The slider on the Cape Cod
adjusts the rate of burns.
4. Travis industries Hybrid-Fire technology™ developed an automated “Greenstart” which shoots 1,400 degree air into the firebox for 15 minutes to start your fire, or when you reload. The Greenstart can significantly reduce start-up emissions, and emissions during reloading on a low temperature bed of coals, by jumpstarting the start-up process and heating the wood up faster than it would with newspaper. After the first 15 minutes, the stove has no automated features, but some of the Travis stoves that use catalysts are among the cleanest in the industry. The Travis Cape Cod stove won second prize in the Wood Stove Decathlon.
5. The Nestor Martin’s Efel has an “automatic mode” that can keep the room at a desired temperature. Or in timer mode, it can adjust the room temperature at a pre-set time. The stoves uses a simple ambient air thermostat in a remote control device that you can operate from the couch or anywhere nearby. If you don’t use it in automatic mode, the remote control allows the user to adjust the intensity of the fire just as you would with a manual air control. One of the key things that distinguishes this Efel from truly automated stoves is that there are no sensors in the stove that can prevent the stove from smoldering or override an adjustment by the operator that would make the fire smolder.
|HWAM’s Autopilot technology uses
sensors, along with a bi-metal spring to
regulate combustion temperatures.
6. The final two stoves are more fully automated stoves and are on the market in Europe, but not in the US. Danish company HWAM, whose automation will be third-party tested and assessed at Brookhaven Lab in November, has integrated a new patented system-Autopilot. Along with the Austrian Rikatronic, described below, the Hwam is one of the most advanced and fully automated stoves in Europe. HWAM 3630 IHS features a control system that electronically measures combustion conditions through the use of a lambda oxygen sensor and a thermocouple. An onboard computer then allocates combustion air through three separate valves to help the consumer achieve the same results at home that are obtained in test labs under ideal conditions. According to the Danish Technological institute, HWAM stoves with this system are 17% more efficient and produce 40% more heat.
|Rikatronic has a microprocessor-controlled
motor and a flame temperature sensor
which drives the RLS air distribution system.
The light tells you the optimal time to reload.
By pressing the button, the stove knows
it has fresh wood to handle.
7. There are numerous versions of the Rikatronic wood heater system. The Fox II stove features manual and automatic control settings. In manual mode the air distribution can be controlled in each combustion phase-even in the event of a power outage. Automation in Rikatronic technology works with a microprocessor-controlled motor and flame temperature sensor which operates the RLS air distribution system. Airflow in each of the 5 combustion zones is effectively adjusted for efficient burn. A red light indicates the optimal time to reload the stove. You can set the room temperature you want and once the required room temperature is reached, you can activate the eco mode by pressing the Rikatronic³ button. This causes the air supply to be optimally controlled to maintain the fire for as long as possible, without smoldering, and to leave behind as little ash as possible. Power consumption is 2 – 4 watts.
The first five stoves described here represent American innovations that can partially reduce excessive wood smoke, while the last 2 stove from Europe represents a more holistic approach that can help reduce emission not just in the start up, but throughout the burn cycle. They are all still relatively new technologies and we are likely to see more companies improve upon them in coming years.
Posted by Earth Stove on July 25, 2015 with No Comments
Updated on Nov. 24
Part of the Workshop rules was a requirement that teams had to publicly share their test results, which is a key part of the collaborative and educational process. During the Workshop, each team presented their test data to the 50 attendees who had the opportunity to discuss the results and give feedback to the team. Unlike EPA test, which starts when the stove is already hot, we used a warm start, capturing some start-up emissions, we used cordwood instead of crib wood and we used higher moisture content wood. Note: any gram per hour (g/h) references in the below test results are not comparable to g/h values from EPA test labs because we did not follow the Method 28 test protocol.
1. MF Fire, the Mulciber. Powerpoint link.
2. The Kleiss stove. Powerpoint link.
3. Wittus Twinfire, Powerpoint link.
4. The VcV, PDF link.
5. Catalus Ventus, PDF link.
Team Presentations about their Stoves
Each team presented the concepts and technologies in the stoves. For a brief technical overview of all the stoves with contact info for the Teams, click here.
1. The Mulciber (powerpoint)
2. The Wittus Twinfire (pdf)
3. The VcV (pdf)
4. The Catalus Ventus (pdf)
5. Kliess (powerpoint)
During the Workshop, there were a series of expert presentations and webinars about automation, traditional stove technology, public health implications, air quality, regulatory issues and other relevant topics.
1. Dr. Tom Butcher, Brookhaven National Lab, Review of the Automated Stove Test Protocol (powerpoint)
2. Webinar with the five teams, hosted by BTEC.
3. Glenn Miller, Fairbanks Air District, Technology Improvements vs. Behavior Modification (powerpoint)
4. Ellen Burkhard, NYSERDA, Renewable Heat New York (powerpoint)
5. Norbert Senf, MHA, Emission Testing of Masonry Heaters (powerpoint)
6. Gael Ulrich, Smoke Particle Formation Fundamental, (pdf)
7. Peter Cullen, Wohler SM 5000 (powerpoint)
8. Phil Swartzendruber, Puget Sound Wood Stove Retrofit Open Challenge (pdf)
Feedback Survey: Results of a 10 question feedback survey about the Workshop by teams, participants and organizers.
Photos: Day 1
|Ivana Sirovica, Jessica Peterson and Jeff Hallowell, from ClearStak Brookhaven National Laboratory.
|Rebecca raking coal bed to prepare for the next load of fuel.
|Thanks to John Pilger and Chimney Safety Institute of America and Olympia Chimney for donating pipe and installation!
|Indigo Hotel in Riverhead NY – our base for the week
|The Testo shows real time emissions, with top line showing particulate matter (PM)
|Rebecca Trojanowski removes filters. The dark circle in foreground are the particulates on a filter from the test burn that will be weighed to determine grams per hour.
|Even the kindling is carefully weighed so that each stove gets the same warm up rick.
Jessica Peterson from ClearStak working late into the night to prepare for testing tomorrow.
Photos: Day 2
Taylor Myers showing a thermal image of the Mulciber stove.
Ben Myren, Tom Butcher and Eric Schaeffer firing up the New Zealand VcV stove.
Lab in Bldg 815 with the VcV and Kleiss stoves. (They brought 2 of exact same stove in case they needed it.)
Taylor Myers showing a real time digital display, using bluetooth, of temperatures in his stove.
Developed by ClearStak, this real time digital display shows 154 degree stack temperature, 529 in the firebox and 451 in the catalyst. Estimated efficiencies were in the mid-80s.
Glenn Miller from the Fairbanks Air District on the left, Rob Rizzo from Mass. Dept. of Energy, and Gaetan Piedalue and Marc Suave from Polytest Labs, a EPA accredited test lab. Ellen Burkhard from NYSERDA is peering into the stove.
Ben Myren, Tom Butcher and Eric Schaeffer firing up the New Zealand VcV stove.
The Wittus Twinfire’s downdraft mechanism, where the fire gets sucked into lower chamber and then passes through catalyts before going back up the stack.
Corey Van, one of the young ClearStak staff that helped build the Catalus Ventus.
Rebecca Trojanowski loads the Catalus Ventus.
The new Testo moisture meter that reads moisture without “pinning” the wood.
Norbert inspects the Condar, placed right below the triple walled pipe.
The tube on the right of black pipe is a Condar, which operates very similarly to a dilution tunnel. Norbert Senf is using it concurrently with the Testo PM analyzer.
A warm up test load made by Ben Myren. This top down burn, with smallest kindling on top, and larger kindling on the bottom is a very efficient way to start fires.
Amanda Aldridge of the EPA talks with Norbert Senf (behind flue pipe) about the Condar analyzer. Rob Rizzo from Mass. Dept. of Energy in upper right.
Electronic controllers that can be put in wood heating systems that were part of Jeff Hallowell’s presentation. Harold Garobedian in red jacket on right, and Rafael Sanchez from the EPA behind him.
A new Testo moisture meter that works without pins. It can measure moisture at the center of the wood, not on the edge.
George Wei hangs almost upside down to put a temperature sensor in the top of the flue pipe to measure stack temperature. This is a key data point for determining efficiency.
John Ackerly on opening day, welcoming everyone and talking about how automated stoves can solve many problematic issues issues that come with widespread wood burning.
From the left to right – Ellen Burkhard from NYSERDA, Lisa Rector from NESCAUM, Amanda Aldridge from EPA and Mark Knaebe from US Forest Service.
We spent hours in this room, having different presentations every hour, with lots of discussion and debate. Here, Ben Myren is presenting the testing results of the VcV stove.
Brian Gauld of New Zealand, John Pilger of CSIA and Jeff Hallowell of ClearStak.
Team Wittus Twinfire
Gregory Elliiot and Peter Cullen from Wohler, and John Pilger from Chimney Safety Institute of America.
Ingo Hartman, measuring glass temperature on his Twinfire stove.
We managed to find a BYOB restaurant which led to more red wine consumption. From left – Rod Tinnemore, Dave Misiuk, Amanda Aldridge, John Ackerly, Norbert Senf, Ellen Burkhard and LIsa Rector.
The Catalus Ventus shows incredible hot catalyst temps compared to the both the stack and the firebox. This was during start up, when it was emitting maximum smoke, but between the catalyst, the fabric filter, virtually no smoke came out the stack.
Ivana Sirovica, a Research Fellow from Alliance for Green Heat, and Ben Myren, as Ben finished the final test of the week.
Tom Butcher using the Wohler particulate analyzer on the VcV stove. Because we used wood that was often above 25% moisture content, we had to deal with more moisture in our testing instruments.
Underneath the VcV stove is where the magic happens, and mechanical valves automatically close or open the primary or secondary air, depending on what the stove needs to maintain a clean and efficient burn. THis stove maintained a steady low burn rate with beautiful swirling flames in the upper part of the chamber.
Ben Myren shows how his thermocouples could read the temperature in 10 spots of the stove at all times. The top of the flue could be 250, when the air entering the catalyst was nearly 800, and 1300 in the firebox.
Brian Gauld, the owner of the VcV travelled from New Zealand, where there is also demand for automation that can improve stove performance far more than stoves are likely to perform when operated manually.
Dr. Phil Hopke of Clarkson University and Mattian Woll of Testo.
Our cord wood was kiln dried and then shrink wrapped so it would maintain a constant moisture content. The wood was far wetter, on average, than wood used in EPA test certifications, which helped us assess how these automated stoves could perform with higher moisture content wood.
Preparation of kindling for the tests.
George Wei and Yussef were two of Brookhavens talented technicians. Both have worked on improving oil combustion systems, outdoor wood boilers and stoves.
The last stove is taken out, and demonstrates the challenge of testing the same day as removing stoves that are still hot!