Meet the Contestants; Kimberly Stoves

With the first Wood Stove Decathlon only a few months away, we here at the Alliance for Green Heat have started a weekly blog post to showcase the Decathlon competitors. Take this opportunity to learn more about the design teams and their stove’s innovative features.

Kimberly may be small, petite even, but don’t underestimate her. Standing just over two feet, the wood

stove will be a big competitor this year. The stove combines a gasification chamber on the bottom and an afterburner on top to burn the smoke for a more efficient use of the fuel. The many other features and accessories, such as a thermo electric generator and hot water coils, help make Kimberly even more appealing to consumers.

Roger Lehet, designer and team captain for the Decathlon, created the stove with off-grid and emergency preparedness in mind. Easy to use and portable, the latest models of the 56-pound stove can heat up to 1500 ft² of well-insulated living space. However, it was originally designed for heating small spaces such as boats, RVs, and cabins. In fact, the first version of the Kimberly stove that Lehet ever built was used for a boat.

During the financial crisis, Lehet lost his business of 25 years as a wood stove dealer. He lost his house and many of his possessions. Financially anchorless, he moved with his wife and daughter to live on a boat floating on Puget Sound in Washington. When winter came, the cold and the damp were unwelcomed guests, inviting melancholy and mildew. The need for warmth and dryness mothered a new stove, one that used a small amount of fuel to burn nearly smokeless all night. Lehet used his knowledge of wood fired products to build the first Kimberly. The family could now heat their boat, cook all their meals, and heat water for sanitation and cooking.

Roger and Bridget Lehet

From there, without a single loan, Kimberly stoves took off. Lehet now has had his EPA certified stove manufactured and sold for over a year. He also has had great success in promoting his product and efficient residential biomass heating in general. Lehet has attended the past two Mother Earth News Fair events in Washington. The fair is meant to deliver practical, hands-on training, and experience taught by leading experts in renewable energy, organic gardening, sustainable agriculture, and green home building. Lehet spoke on off-grid technologies such as thermo electric generation, wood-fired in floor heat, and domestic hot water.

We are looking forward to seeing little Kimberly in action at the Wood Stove Decathlon November 16-19, 2013. Vote for your favorite stove at Popular Mechanics.

Pellet Boiler Also Makes Enough Electricity to Power Home

Austrian company OkoFEN has brought to market the first residential electricity producing pellet boiler, the Pellematic Smart_e. The boiler uses a pellet-condensing module from an earlier pellet boiler design, the Pellematic Smart and outfitted it with with a Microgen Stirling Engine. The engine uses a heated/cooled helium hydraulic system. The result of these two technologies is a unique boiler that is capable of outputting 14 kW (47,770 Btu/h) of thermal energy and 1 kW of electricity.

The Pellematic Smart_e can save households’ money on both heat and electricity bills. Switching from oil, propane, or electricity to pellets usually results in substantial savings. The heat is used for space heating of the living area and domestic hot water generation. Plus with the added Stirling Engine, the electricity you produce in your own house can offset part of a home’s monthly electricity bill. A full load of 24 hours can produce 24 kWh of electricity at 1kW.

At 24 kWh per day, the Pellematic Smart_e could generate enough electricity for most or all of a home’s average daily electricity needs. However, in order to create this electricity, the boiler must run at full capacity, which can create a substantial amount of excess heat. The surplus heat may be stored while the electricity is still produced but even with the heat storage capabilities, some of the heat may be lost, and the efficiency of the boiler falls. For the Pellematic Smart_e to meet the electricity needs of a house, it would have to extend far beyond the heating needs of that house.

“The issue is the large 14:1 ratio between thermal and electricity on this unit, and the (likely) narrow output curve,” explains Norbert Senf, one of the judges for the Wood Stove Design Challenge, “In a thermal electricity generating station, you get about a 2.5:1 ratio.”

Although it is perhaps not the most efficient when it comes to producing electricity, OkoFEN’s innovative boiler demonstrates the potential of this hybrid technology. The success of this product is likely to lead to further industry advancements to manufacture and distribute pellet boilers capable of producing even greater amounts of electricity.

For more information check out OkoFEN’s website here

Also, their FAQ page here

Privately Financed Change-out Programs Started by Jotul and NH Retailer

Two separate, privately financed, wood stove change-out programs were started this summer with the aim of selling more new stoves in the off-season and removing as many old, uncertified ones in the process.

Jotul’s national program has Jotul dealers give a $100 to $300 discount to consumers who turn in an old, uncertified stove. The discount is funded half by Jotul and half by the retailer. Consumers can drop their stoves off at an authorized Jotul dealer or a recycling center and provide the receipt to the retailer to prove the old stove has been retired. 450 out of 1,000 Jotul dealers in the U.S. and Canada are participating in the program so far. Jotul is also donating $10 to the American Lung Association for every uncertified stove that it is taken out of circulation.

Fireplace Village, a New Hampshire hearth retailer with four locations, is providing an even more

generous offer to consumers. They are giving a $500 discount to consumers who trade in an old, uncertified wood stove. They have also discounted their removal fee to $100 if the consumer wants them to remove the old stove.

Change-out programs typically are undertaken mainly with government funding and often with in-kind assistance from the stove industry. Those change-out programs tend to provide higher rebates or discounts and also often have high overhead costs to manage the program. These privately funded and managed change-out programs are likely to result in the removal of hundreds of old stoves this summer and help families heat with cleaner, more efficient stoves. This could be a program that other manufacturers and retailers use as a model.

Better Business Bureau Rates Wood Stove Companies

Few consumers probably check the Better Business Bureau before buying a wood or pellet stove or boiler.  But they should. Most wood stove experts will probably not be surprised by the rankings on the chart below. The good news for the wood stove industry is that the majority manufacturers we found on BBB received an A+ or A-. 

It’s important to understand the limitations of the BBB – and to rely on multiple sources. Unfortunately, Consumer Reports has done only a very limited review of pellet stoves and nothing on wood stoves. There is this good review of pellet stove reliability. Hearth.com is also a great resource and the Alliance for Green Heat reviews some other sites here.

The volume of complaints alone does not heavily impact a company’s grade.  Otherwise, the largest manufacturers would have the worst grades and the companies that only sold a few thousand stoves a year would have the best.  The BBB tracks consumer complaints and monitors if they have been resolved.  In their grading method, different point values are assigned to 16 weighted criteria. They include complaint volume, unanswered complaints, unresolved complaints, serious complaints, failure to address a complaint pattern and advertising review. Failure to respond to consumer complaints and to resolve them are weighted heavily.

We searched the BBB site for all major stove companies and found many of them there. We could find only one European stove company (Jotul) and several Canadian ones. For companies that own several brands such as Hearth & Home Technologies, we found one of their brands, Harman, separately listed but could not find another, Quadra-fire, for example.

* Prior to July 2013, when this blog was published, US Stove has "a history of violating BBB name and logo policy and has falsely stated BBB accreditation," according to the BBB. As of August, 2013, US Stove, "responded the BBB by removing all reference of BBB's name/logo from their website."  The BBB website still says, "There is an alert for this company."  

Series 1 marks the number of resolved complaints. Series 2 marks the number of complaints that received no response. It is promising to see that many stove manufacturers receive very few consumer complaints. Also, the complaints they do receive appear to be responded to and resolved professionally and effectively.

The points are added up and a letter grade (A as the highest, F as the lowest) is assigned accordingly. In order to receive a good score, the volume of consumer complaints that are not responded to must remain low. The BBB takes into consideration whether the business makes a speedy and honest effort to fix the problem and resolve the complaint. The response of the business can mean the difference between an A and a B score. For example, as seen in the graph, Central Boiler received 33 consumer complaints. Despite this large number, the manufacturers response and resolution of these complaints still earned it an A-. Click here to read a full overview of the BBB grading method.

Only a small fraction of consumer complaints are handled by the BBB. Usually consumers first go directly the manufacturer and only if that proves unsuccessful do consumers approach the BBB.  Instead of BBB, or in addition to it, consumers can go to their the State Attorney General’s Office. A full index listed by state is provided here. At the federal level, the Office of United States Attorneys maintains a consumer complaint file to track allegations of consumer fraud.

The BBB has been criticized for their apparent subjectivity and preferential grading of BBB accredited businesses.  It is the consistency and the transparency of the test that determines its ethical merit and credibility. The Los Angeles BBB was the branch responsible for the preferential grading of businesses, and has since been disassociated from the national council.

While wood stove companies fare relatively well on BBB, some other products in the hearth industry do not. Heat Surge, the Amish "miracle heater" that is heavily advertised and is also a exhibitor at HPBA trade shows gets a c minus rating and has hundreds of complaints filed against it. The Alliance for Green Heat has previously written about it here.


Update: (7/15/13) US Stove's BBB rating has changed from Not Rated to a B rating. The company is still not BBB accredited.

Update: (8/20/13) US Stove responded to BBB by removing all reference of BBB's name/logo from their website. BBB has closed this advertising challenge as resolved.

Further reading:

Wood and pellet stove companies improve ratings with the Better Business Bureau; but does it matter? (Jan. 2017)

Napoleon's "EPA certified - exempt" fireplace?

Napoleon has labeled one of its fireplaces “EPA certified – exempt.” According to the EPA, this wording is not allowed. For consumers it is confusing at best, but can also be misleading or false advertising. The fireplace is the NZ6000 High Country and it’s an exempt unit, meaning it does not conform to EPA emissions standards.

Wöhler Brings New Particulate Analyzer to Wood Stove Design Challenge

The German precision test equipment manufacturer, Wöhler, is providing one of its new Wöhler SM 500 particulate analyzers to do accurate PM 2.5 testing in the field. The Wöhler unit is a Suspended Particulate Analyzer for online PM 2.5 mass concentration measurements of small solid fuel appliances. The brand new technology just came out last year to meet requirements under a new German law that requires wood stoves and boilers to be checked in the field for emissions every year. German chimney sweeps play the same role as vehicle emission testing stations in the US. If the emissions are too high, the problem has to be fixed or the system taken out of service.


The Wood Stove Design Challenge will be using the Wöhler equipment at its national exhibition to educate policy makers and the public about modern wood heater emissions. The 10 judges who are preparing for the Challenge are gaining experience in using the new Wöhler technology in anticipation of using on-site testing of emissions. The Wöhler SM 500 is now at the Brookhaven National Laboratory where one of the judges, Dr. Thomas Butcher, is performing trial testing. Other judges will join him in coming months as they test the fueling protocol and compare the Wöhler SM 500 to the traditional, but more cumbersome, dilution tunnel test procedure that is used in wood stoves tests to ensure they meet EPA emissions standards. Dilution tunnels are large, time-consuming and expensive to use and are not an option for testing up to 14 wood stoves on the National Mall over a 5-day period.