Tuesday, July 31, 2018

Meet the teams: University designs unique 3 chamber wood stove for design competition

This post is the tenth in a series introducing the 12 teams participating in the 2018 Wood Stove Design Challenge in November.

By Ken Adler and Shoshana Rybeck, Alliance for Green Heat

The Stony Brook University team and
the Lumburnator
In 2015, students from Stony Brook University in New York received a grant from NYSERDA to participate in the 2016 Wood Stove Design Challenge. The team is led by Professor Devinder Mahajan, Director, Institute of Gas Innovation and Technology and Professor of Chemical and Molecular Engineering at Stony Brook University, and Abe Montes, an undergraduate student in the Materials Science and Chemical Engineering Department acting as team leader. Dr. Devinder Mahajan received his Ph.D. from the University of British Columbia, Canada and completed his post-doctoral training at Brookhaven National Laboratory (BNL), joining the Stony Brook University Faculty in 2002. 

The team has four undergraduate students that change year to year as members graduate. Now, in its third year, their automated stove, known as the “Lumburnator” is going through design operation and testing cycles at the Advanced Energy Research and Technology Center. This is in preparation for the November 2018 Design Challenge in Washington, DC.

Technology packed with innovation
Schematic of the Lumburnator 

The team’s main focus is to show that clean, efficient, wood combustion is possible without sacrificing commercial viability. To achieve this goal, Stony Brook has included four innovative features into the Lumburnator. The first is the addition of a drying chamber inside the stove. The theory is that by using heat from the combustion chamber to dry subsequent fuel charges, startup emissions from subsequent charges can be reduced. 

The second is electronic controls. The Lumburnator’s electronic control system automatically adjusts the stove’s operation based on flue stack temperature. The third is an innovative heat exchanger. The high surface area present in the Lumburnator’s exhaust remediation section, improves heating efficiency and helps to capture particulate emissions. The final innovation is a venturi draft inducer. The Lumburnator is a downdraft wood stove, which uses the negative pressure generated by the draft inducer to draw air through the firebox for combustion.

The vision that drives them

The Lumburnator in the lab. 
The Luburnator has many unique and innovative features, and Devinder says that a big benefit of the Design Challenge will be getting the opportunity to address the pushback they’ve received and show that “there are ways to conform to the new EPA standards while keeping price in mind.” Throughout the project, the Stony Brook team’s vision has been based on what the team calls the “three pillars”: designing a stove that operates easily and safely, reduces emissions, and is affordable. The Stony Brook team believes they have a commercially viable design and are enthusiastic about the Lumburnator successfully competing in the Design Challenge this November at the National Mall in Washington DC.

Contact the team

Devinder Mahajan

Abe Montes

Wednesday, July 18, 2018

Meet the teams: A young company automates the wood stove and challenges the established stove industry

This post is the ninth in a series introducing the 12 teams participating in the 2018 Wood Stove Design Challenge in November.

By John Ackerly and Shoshana Rybeck, Alliance for Green Heat 

Ryan Fisher
In 2013, a group of students from the University of Maryland with absolutely no experience in stove building, entered a stove into the first Wood Stove Design Challenge. They had built one of the first automated stoves in America and it worked surprisingly well though it clearly was a prototype that needed a lot of work. Some seasoned stove experts scoffed at their efforts, but they persisted and despite the odds, released the stove onto the market 2017.

The team is back for the 2018 competition with a new stove which is simpler and sleeker. Along they way, they morphed from a University team to a company, MF Fire, based in Baltimore and backed by some venture capital.

“We’ve learned a lot,” says Ryan Fisher, the 28 year-old COO of the company, who never imagined he would end up in a career working with wood stoves. They still have a lot of skeptics but they are starting to earn a niche in the industry as they continue trying to disrupt it. The company is based on the premise that “wood stoves haven’t changed much in decades but there is no reason a wood stove should be polluting, inefficient or difficult to use.” They use sensors that can find the combustion “sweet spot” that any stove can hit, but few stoves or operators can stay in the sweet spot for very long.

MF Fire developed an app where a user can control temperature and monitor the status of the fire inside the stove. Throughout, it’s collecting data to learn more about the environmental conditions as well as when the user likes to burn. Ryan told us that they “locate thermocouple within the stove in combustion areas. Based on the current and past readings of the stove as well as user inputs, the smart controller is able to make automatic adjustments to the combustion.”

MF Fires stoves can be 
controlled via aphone app

The company is now able to sell it for $4,000, trying to tap into environmentally conscious consumers who appreciate high tech appliances. The basic version of the stove, the Nova, that they are entering into the 2018 competition sells for only $2,490 but will have optional automated features that will bring the price over $3,000. The stove has a catalyst that is manually engaged and went through certification testing and met the 2020 standards as a single burn rate stove. Their model uses Schott Robox glass, a spondor of the 2018 Wood Stove Design Challenge. The company is now waiting for the EPA to formally approve the test and post the certification results.

Using technology to maximize efficiency - and safety
The new NOVA stove 

In addition to thermocouples that relay temperature data to the smart controller, the Catalyst and the automated version of the Nova have an induction fan integrated in the stack that can modulate air flow through the stove. Induction fans are perhaps one of the biggest ways to automate the operation of the wood stove in an industry relying on natural draft chimneys. Ryan says that “one of the biggest benefits of the fan is that it gets through the dirtiest part of the burn very quickly from a cold start. You can close the door right after lighting, and the sensors and fans will ensure the stove gets plenty of air. Unlike most other wood stoves, there is no need for leaving the door or ash pan ajar on Catalyst during startup.”

The thermocouple sensors, fan and smart controller also greatly enhance safety. They can prevent over-firing, which can be dangerous to the stove and lead to chimney fires, and they can prevent the conditions that lead to creosote build up in the first place. And, the MF Fire Smart App has wood stove safety features, including a built-in alarm that will alert an owner that a stove door has been left ajar, enabling the door to be secured quickly and safely.

MF Fire: A technology development company, not just a stove manufacturer

Ryan Fisher and the original Catalyst
MF Fire has been working on developing the smart controls for the stove, that will allow the user to better track their stove’s behavior, control its burn, and operate it safely.

MF Fire is a technology development company first and foremost, working to introduce modern smart controls to an age old form of heat production. Ryan believes that approaching this challenge from a technological development standpoint gives them a unique outlook that they are excited to share in November. Some stove manufacturers are churning out stoves designed 20 years ago and are mainly manufacturing companies, and have minimal in-house R&D capability. They may be skilled at creating well built stoves but they are part of a status quo in the industry that is not keeping up with the rapid technology changes that encompass modern appliances in the HVAC and all other sectors.

That technical acumen within MF Fire led their very first stoves to meet the stricter 2020 EPA emission limits and they hoped that their company would have an edge in the market as of 2020. Now that the EPA has signaled a willingness to consider delaying the stricter standards until 2023, MF Fire may not have the edge that they were hoping for. They still believe that there is a more environmentally conscious, possibly younger demographic who want to get off of fossil fuels with an advanced, modern wood stove. The 2018 Stove Challenge provides a platform to prove their new stove and introduce it to a wider audience.

Contact the team

Ryan Fisher, COO

Paul LaPorte, CEO

Wednesday, July 11, 2018

Meet the Teams: A micro CHP pellet unit makes its debut on the Washington Mall

This post is the eighth in a series introducing the 12 teams participating in the 2018 Wood Stove Design Challenge in November.

By John Ackerly, Ken Adler, and Shoshana Rybeck, Alliance for Green Heat

The Pellematic e-max with a cut-away
view of the Qnergy Stirling engine that
makes the electricity.
If all goes as planned, Maine Energy System’s (MESys) ÖkoFEN Pellematic e-max will power all the testing equipment, lights, computers and audio equipment for this year’s Wood Stove Design Challenge on the National Mall. Having recently hit the market in Europe, the Pellematic e-max is designed for “commercial enterprises, hotels and residential complexes,” producing up to 4,000 watts of electricity.

Renewable combined heat and power (CHP) technologies that can supply 100% of heat and electricity to a home or small business come in many forms and are often part of an integrated system with solar panels. The key is matching the electrical needs with the heat needs because 95% of the energy from a pellet CHP unit will be heat and only 5% will be electricity. Thus, hotels or restaurants that need a lot of hot water year round make up many of ÖkoFen's customers for this product.

A smaller version, producing heat and electricity for single family homes, was slated to come to the Wood Stove Design Challenge until organizers asked for the larger version. The residential one has a track record with scores of homes in Europe that use solar panels for electricity in the summer and additional electricity from pellets the winter.   

The Pellematic e-max is designed for a “medium power range”, producing 50-60 kW of thermal power and 4-5 kW of electrical power. To yield these energy outputs, the Pellematic uses ÖkoFEN’s pellet heating system paired with Qnergy’s Stirling engine technology, which has allowed the model to be energy-efficient, low emitting, and a reliable source of heat and power, simultaneously. 

Pairing the Pellematic e-max with solar panels and a smart controller enables the system to use whichever energy source is cheapest at that moment. It plans for upcoming days based on weather forecasts. When its sunny, the system prioritizes the solar panels and can store electricity in a battery for cloudy days. If electricity from the grid is cheapest at night the controller will take electricity from the grid and also store cheap night time electricity to a battery. In the winter, when a lot of heat is needed, the controller will prioritize pellets. The homeowner or business owner does not have to do anything as the system switches between pellets, the sun, the battery or the grid. ÖkoFEN also manufacturers Pellesol solar thermal panels that combined with the pellet boiler can produce hot water for heating and all hot water needs year round.

Alone, the ÖkoFEN boiler provides reliable, economical and efficient heat output when the combustion conditions are kept constant, which makes it a strong base load boiler for commercial  buildings and reliable primary heating source for large households. However, with the attached Qnergy Stirling engine, this powerful heater can be used to produce substantial amounts of electricity
If a home has an electric car, the system
can also switch from pellets to solar to the
grid, depending on which combination of
electric sources is available and cheapest.
as well. When heat from the boiler is transferred to the Qnergy engine, pressure increases and works with the engine’s cooling circuit to create the temperature and pressure differential needed to move the Stirling piston and create electricity.

Developing MESys

Dutch Dresser (middle), Les Otten 
(2d from left) and MESys colleagues
Generating electricity from wood stoves was anything but the projected path for Dutch Dresser. His undergraduate education was in biology and Masters and Doctoral degrees are in science education. Before helping to create MESys in 2007, Dutch had an array of careers in education, computer networking and land development in Maine. Dutch says that he was moved to develop the company when his friend and partner, Les Otten, saw that the region was exporting monumental amounts of money for heating fuel and systems. 

Using the European heating market as an example, Les, Dutch, and Bill Strauss saw that there was a alternative way to run the heating market so that it supports the local economy without fossil fuels. Unlike the northeastern US, the European heating market kept heating dollars in the local economy by selling renewable, locally sourced units. Inspired by the European model, Dutch and Les set out to work with European heating technology to create a local market in Maine, and eventually grew throughout the Northeast.

After getting rejected by many European heating equipment manufacturers who feared working in the litigious America marketplace and one early experience with a problematic product, MESys began working with the Austrian company ÖkoFEN in 2009. Since then, MESys has become the  North American manufacturers for ÖkoFEN.  The bread and butter of Maine Energy Systems are residential pellet boilers that typically cost $8,000 to $15,000 after state incentives in Maine, New Hampshire, New York, Vermont and Massachusetts. The cost of the E-max for small business or multifamily
A comparison of the economics of
four installations of the E-max.
units would be $30,000 or more, but case studies have shown a payback period of 3 - 11 years in Europe.  While the economics of the e-max can make sense in Europe, the demand for the unit is also driven by customers who want to go the extra mile to use renewables, based on their values and the values of their customers.

The barriers of bureaucracy

Different emissions and safety testing protocols have been one of the major challenges to bringing innovative pellet central heating technologies, like the ÖkoFEN e-max, to the market. (European certification testing requirements are not accepted in the US so they have to be certified again in the US.) In Europe, new pellet boilers are being introduced every year and consumers can see these improved products online. But there is no way that an American company can pay to have each model EPA certified in for the US market when sales are still low. Dutch says that the time these tests can take can be “a barrier to innovation.” For Dutch, slow technological transfer in the marketplace is “a system wide issue, not just about boilers or cars, but about absolutely everything.” But it impacts appliances with low sales volumes the most. 

Europe’s best at the National Mall

Maine Energy Systems typically sells to the northeastern US and all of Canada, so the team sees this challenge as an opportunity to expose European boiler technology to a new continent. For Dutch’s vision of global collaboration to make ever more efficient renewable technologies, this challenge means a lot. With such low fossil fuel prices in North America, very few people know about the low carbon heating technologies that are very common in Europe. And the Pellematic e-max is a leading edge technology as it produces heat and electricity that can be paired with solar and other technologies to supply 100% of a home's energy needs.  

Contact the team

Dutch Dresser

Dan Wheeler

Tuesday, July 3, 2018

Meet the teams: A wood stove for off-grid lefties, right-wing preppers, and everyone in between…

This post is the seventh in a series introducing the 12 teams participating in the 2018 Wood Stove Design Challenge in November.

By John Ackerly, Ken Adler, and Shoshana Rybeck, Alliance for Green Heat 

Roger Lehet on the boat where
he developed his Kimberly™ stove
Like so many other businesses in 2008-2009, Roger Lehet’s 25-year-old brick and mortar wood stove shop was a casualty of America’s Great Recession. When the dust finally settled, the Lehet family of three found themselves living “with nothing and no money” on a boat moored in Puget Sound off the coast of Vashon Island, a fifteen-minute ferry ride from Seattle, Washington. Roger realized that no manufacturer made a wood stove that could fit into the tiny space he carved out of the boat’s cabinetry, so Roger cobbled together the very first prototype for what would later become known as his Kimberly™ stove.

It then occurred to Roger that a thermoelectric system could allow his family to comfortably live off-grid and that his wood stove should provide not only the ability to heat their space, but to also allow his family to cook, bake, heat water, and create electricity. Word traveled quickly and one day a local Vashon resident showed up at the dock, advising Roger to “make it look pretty and get a patent on it.” By the fall of 2012, Unforgettable Fire™ was a newly minted entity and Kimberly™ had passed the rigors of  EPA-CSA and UL testing protocols.

Roger Lehet knew that creating electricity from the heat of a wood stove was possible because he read somewhere that “the Russians did it during World War I.” Roger was also aware that (until the 2018 Wood Stove Design Challenge) no one in the United States was commercially developing this technology, so he gathered a team to explore the possibilities, using the World War I era successes in Russia as a starting point. 
The Kimberly stove

In 2013, the Unforgettable Fire™ team entered Roger Lehet’s Kimberly™ stove in the very first Wood Stove Design Challenge. EPA-CSA certified at 3.2 grams per hour, and weighing only 56 pounds with a tiny firebox of 0.2 cubic feet, Kimberly™ became a darling of the tiny house, RV, and prepper markets, despite selling for nearly $4,000 USD. While many of the 2013 Design Challenge stove entries required a forklift to unload and place inside our tent which was located on the National Mall in Washington, D.C., Roger arrived by taxi, carrying his Kimberly™ stove in his arms. 

Despite having developed Kimberly™ on the deck of a boat, Roger found that the marine community was a harder market to penetrate. Nevertheless, in a matter of years, Lehet sold over 500 Kimberly™ stoves to people living in small and tiny spaces, and to preppers, “many of whom still have not even unpacked their survival stove,” Roger shared with us.

Fueled by his success with his first stove, Kimberly™,  along with the experience of the 2013 Design Challenge, Roger was inspired to create additional wood stoves. Roger’s Katydid™ model debuted in late 2014. EPA-CSA certification testing came in at 1.9 grams per hour, exceeding the EPA emission standards for the year 2020. “I am amazed how much the solid fuel heating industry has cleaned up its act since the unregulated stoves in use when I started as a chimney sweep in 1985,” Roger said. “At one time, we were dumping up to 85 grams per hour into the air. I well remember my lungs stinging as I walked to the bus stop each winter morning as a kid in school.”

Roger’s vision for a multi-use stove has attracted a number of talented people. Among
Team member Vanessa Kelly. Photo by
Dorothy Ainsworth.

them is 
Vanessa Kelly, who showed up on his doorstep in February 2013 and is second in command at Unforgettable Fire™. Vanessa handles everything from web development and online marketing, to sales and technical support. In September 2014, when Roger was on the East Coast as a vendor at a trade show, Vanessa was Roger’s eyes and ears through the EPA-CSA certification process for the Katydid™ wood stove at OMNI Test Lab in Portland, Oregon. Vanessa wrote the accredited owner’s manuals for both the Kimberly™ and Katydid™ models and served as project manager for the EPA-CSA labels. 

When Roger teamed up with the folks at TEGmart, a company that sells thermoelectric components, Roger gained clarity on how thermoelectric modules (TEGs) could better integrate with wood stoves. Today, as Roger explained to us, his team now “creates the stove to match the potential of the TEGs.” This knowledge has driven the Unforgettable Fire™ team to improve the interface between the hot surface of the wood stove and the thermoelectric modules on the stove. 

Ultimately, Roger and his engineering team decided to flip Lehet’s patented technology,
An early prototype of the
TEG system 
found in the Kimberly™ stove, in order to increase the heat in the TEG units. Therefore, the Unforgettable Fire™ Kd3 prototype under development for the 2018 Wood Stove Design Challenge incorporates a gasification chamber on the top of the stove and a re-burn chamber on the bottom. Completely combusted flue gases exit to the right and left sides of the base of the stove where the water-cooled TEG units are installed. 

Roger stated that the resulting flames are “extremely clean”. From past experience, Roger says the stove has produced an easy 75 Watts when paired with solar panels, which he says could run many 9 watt light strips, a water pump, and send a good bit of energy to the batteries. While they have experienced these outputs so far, Roger reports that he expects to test the electrical production from the Kd3 prototype within the next month as the Unforgettable Fire™ team is currently finalizing the engine. As a side note, the design of the electrical component also allows for the addition of solar panels and wind generation.

The challenges that the Unforgettable Fire™ team have encountered over the years in bootstrapping the company from the deck of a boat have taught Roger Lehet to “challenge conventional wisdom.” From the beginning, Roger’s peers have championed high-velocity stoves as the way to get the cleanest burn possible, but Roger went a different route and also found success. Using a low-velocity model, Roger fine-tunes the mixture of wood gas and oxygen as his central method to achieve a clean burn. Lacking important testing equipment to guide him, Roger assesses the cleanliness of the burn solely from the flame’s color. The wood gasification process in the first burn produces flames that are orange, blue, and purple in color. In the re-burning of those gases, Lehet aims to get the whitest flame possible, as flames which appear white in color contain very few particulates. Roger claims that his Kd3 prototype is “able to sustain 850º Fahrenheit in the exhaust manifolds with plenty of radiant and/or convective heat.” When pushed, the Kd3 prototype can sustain up to 1250º Fahrenheit.

A big challenge for very small stove manufacturers like Unforgettable Fire™ is that they cannot afford well-equipped internal test labs to assess particulate matter emissions before taking the stove to an EPA-CSA test lab. Therefore, Roger uses only thermocouples to test his stoves during the design phase. Since the Kd3 prototype does not utilize a manual air control, Roger Lehet hopes to get an emissions exemption from the EPA.

Independent, off-grid energy

Roger competing in the the 2013
Wood Stove Design Challenge
The experience of the Lehet family living on a boat forged Roger’s unique approach to wood stove design. Roger’s goal for the 2018 Wood Stove Design Challenge, and for the stove market in general, is to bring a wood stove and thermoelectric generation system to market under the Unforgettable Fire™ brand, allowing people to live independent of the electrical grid, with little to no compromise to their quality of life.

Contact the team 

Roger Lehet

Vanessa Kelly