Monday, December 8, 2014
by David Brooks
|Tom Butcher from Brookhaven Lab,
second from right, tests an automated
stove from New Zealand. Ben Myren,
left, did R&D work on it.
I don’t think very hard when I light up the old wood-burning stove in my basement. Turns out, that might be a problem.
“Combustion technology is incredibly complex. Numerous chemical engineers, combustion engineers, mechanical engineers around the world are constantly trying to understand the intricacies associated with combustion. It is absolutely not what you and I would think – just light a match … especially when you want to get clean combustion and use wood efficiently,” said Rob Rizzo, manager of the Renewable Thermal Program for the Massachusetts Department of Energy Resources.
Rizzo was among the organizers of the 2014 Stove Design Workshop held in November at Brookhaven National Laboratory in New York, the latest in a number of attempts to add some high-tech wizardry to that staple of New England life, the wood stove. (For details, see forgreenheat.blogspot.com/2014/11/rookie-wood-stove-makers-get-highest.html)
Why tinker with something as well-established as wood stoves?
Because, like me, most people don’t think too hard when using them, which makes them inefficient and polluting.
We use green wood or wet wood, and we fiddle with the damper in the wrong way, causing partial combustion and thus more pollution.
The Stove Design Workshop, like a national Stove Design Challenge in 2013 that featured two New Hampshire entries, wants to find technology that can better cope with our stupidity.
The five finalists in the design workshop used a variety of techniques to work around people, including oxygen sensors that control fuel-to-air ratio, a common emission-control technique in cars, and a New Zealand stove that has a “barometrically operated variable choke venturi tube” to control the amount of combustion air entering a stove, particularly at lower burn rates.
“The whole concept with the design challenge is to come up with solid-wood stove that eliminates the human interface. Basically hit a start button and walk away; that is the concept we’re aiming at,” he said.
This already happens with pellet stoves, of course, which is why pellets has led a wood-burning renaissance for building heat.
The drawback is that they burn pellets made of compressed sawdust rather than the wood I can snag for free off my property, especially after the Thanksgiving snowstorm knocked down so many big limbs.
The lure of free fuel means that a lot of people still burn non-pelletized wood for some or all of their heat, although it’s not clear how many.
I have never been able to find good data about people who use cordwood (a.k.a. “roundwood”) as their principal heat source, partly because it’s hard to pin down. I, for example, use it only as a minor supplement of the pellet stove in the living room and our oil-fired furnace.
Rizzo said he didn’t know any data either, but he said that wood stoves remain important, especially in western Massachusetts.
Just as important as convenience is cleanliness. Wood stoves can produce a lot of pollution, particularly fine-particle soot, that is a health hazard. This is particularly a problem around Keene, which has a lot of wood-burning stoves and a geography that traps air in certain weather conditions.
New Hampshire has used rebates to get people to turn in their old stoves for cleaner versions, although with limited success.
But those cleaner stoves aren’t all that great; they’re little more than old stoves with catalytic converters in the stovepipe. Hence the push to build a better mousetrap, so to speak.
“It’s exciting to see new ideas coming forward. We have some educated guesses but we need to do better,” Rizzo said.
“We need to collect more data, about efficiency, emissions, consumption volumes, and also source of wood, sustainability of wood source, quality of wood source. Because rural America is always going to be burning round wood.”
A Comparison of Eligibility Requirements for Stoves Incentive Programs
October 31, 2014
* This efficiency level was not measured or enforced in any meaningful way.
** This program only allows upgrades from lower to higher efficiency using the EPA default numbers.
*** MD and ME allow for professional inspection in lieu of professional installation.
**** No efficiency minimum; higher efficiency stoves get higher rebate amounts.
|Taylor Myers and Ryan
Fisher with the Mulciber,
the greatest rating stove.
|The Wittus crew with the Twinfire.|
|The VcV, wired to monitor
temperature in important spots
|The ClearStak staff with the
optimum for emissions.   It was a highly progressive entry, using dual cyclones, a pre-heated, constantly engaged catalyst and a fabric filter.  Its sensors and controller held the oxygen rates extremely steady, in 50 percent a percentage level. The technologies could be built-in into a new stove, or added on to an existing stove. The designers did not consider to optimize performance, which impacted their all round score.
|The Kleiss, all set for tests.|
The 12 member Organizing Committee oversaw building protocols, tests and scoring and included reps from Alliance for Environmentally friendly Warmth, Aprovecho Study Lab, Brookhaven National Lab, Clarkson College, Hearth.com, Masonry Heater Association, Massachusetts Department of Power Assets, Myren Labs, NYSERDA, US Forest Support and Washington Department of Ecology. The Committee is now contemplating possibilities for a 2015 Stove Design Problem.
Portion of the Workshop principles was a prerequisite that teams experienced to publicly share their check results, which is a essential component of the collaborative and instructional approach. For the duration of the Workshop, each and every group introduced their examination data to the fifty attendees who had the possibility to go over the benefits and give comments to the  team.  Unlike EPA test, which begins when the stove is currently very hot, we used a warm commence, capturing some start off-up emissions, we utilized cordwood instead of crib wood and we used higher humidity content material wooden. Be aware: any gram for every hour (g/h) references in the beneath test outcomes are not similar to g/h values from EPA check labs simply because we did not follow the Strategy 28 examination protocol.
Staff Displays about their Stoves
Each and every staff presented the concepts and systems in the stoves. For a brief complex overview of all the stoves with make contact with data for the Groups, click right here.
Throughout the Workshop, there were a series of expert shows and webinars about automation, standard stove technological innovation, public well being implications, air high quality, regulatory concerns and other related topics.
one. Dr. Tom Butcher, Brookhaven Nationwide Lab, Assessment of the Automated Stove Test Protocol (powerpoint)
2. Webinar with the five groups, hosted by BTEC.
three. Glenn Miller, Fairbanks Air District,  Technology Improvements vs. Actions Modification (powerpoint)
four. Ellen Burkhard, NYSERDA, Renewable Warmth New York (powerpoint)
5. Norbert Senf, MHA, Emission Tests of Masonry Heaters (powerpoint)
6. Gael Ulrich, Smoke Particle Formation Essential, (PDF)
Pictures: Day 1
|Ivana Sirovica, Jessica Peterson and Jeff Hallowell, from ClearStak Brookhaven Countrywide Laboratory.|
|Rebecca raking coal mattress to put together for the up coming load of gasoline. |
|Many thanks to John Pilger and Chimney Basic safety Institute of The united states and Olympia Chimney for donating pipe and installation!|
|Indigo Hotel in Riverhead NY – our foundation for the week|
|The Testo exhibits real time emissions, with leading line demonstrating particulate subject (PM)|
|Rebecca Trojanowski gets rid of filters. The dark circle in foreground are the particulates on a filter from the examination melt away that will be weighed to determine grams for every hour.|
|Even the kindling is very carefully weighed so that every stove will get the very same warm up rick.|
|Ivana Sirovica, Jessica Peterson and Jeff Hallowell, from ClearStak Brookhaven Countrywide Laboratory.|
|Rebecca raking coal mattress to put together for the next load of gas. |
|Thanks to John Pilger and Chimney Safety Institute of America and Olympia Chimney for donating pipe and installation!|
|Taylor Myers showing a actual time electronic show, using bluetooth, of temperatures in his stove.|
|Indigo Resort in Riverhead NY – our foundation for the 7 days|
|The Testo exhibits real time emissions, with prime line showing particulate issue (PM)|
|Rebecca Trojanowski removes filters. The dark circle in foreground are the particulates from the check burn that will be weighed to establish grams for each hour.|
|Even the kindling is very carefully weighed so that every stove gets the very same warm up rick.|
|Glenn Miller from the Fairbanks Air District on the remaining, Rob Rizzo from Mass. Dept. of Power, and Gaetan Piedalue and Marc Suave from Polytest Labs, a EPA accredited test lab. Ellen Burkhard from NYSERDA is peering into the stove.|
|Jessica Peterson from ClearStak functioning late into the evening to prepare for tests tomorrow.|
This year there are at the very least 50 % a dozen stoves on the marketplace that have some automatic characteristic that did not exist on the market place a number of several years back. A lot of of these attributes support the stove burn off fairly cleaner, and are aiming at a demographic seeking for simpler procedure. It really is still too early to notify how effectively the automated attributes function, compared to what they declare to do.
3 key players in the US stove production local community – Quadrafire, Travis and England Stove Functions – now have automated methods to lessen commence up and reloading emissions, which is one particular of the most crucial emissions issues that requirements to be tackled. The Travis system makes use of electricity and is likely the most potent of the 3, and the other two never need to have electric power.  The England Stove Functions stove has built-in their innovation in a really affordably price tag stove.
The real assure of automation is not to get a very hot stove to strike an ultra-minimal particulate make a difference amount in a lab, but to boost genuine-planet functionality by seamlessly optimizing performance throughout the melt away cycle, to reducing begin-up emissions and minimizing emissions from unseasoned wooden. EPA certification tests does not try to take a look at these characteristics of a stove, so stove organizations have not experienced significantly incentive to invest a good deal of time, work and income to layout for that.
In the United Kingdom reliable burning heating devices are not categorised by their measurement, i.e. stove vs. boiler, but by no matter whether they are computerized or guide. To obtain a ranking to be utilised in a lot more polluted locations, manually operated stoves need to post lab assessments showing 5 burns for each and every output stage since “manually managed appliances present much greater variation among tests.” Automated appliances only have to be examined three times at every single output degree.
The chart underneath displays a wide assortment of technologies that exists in both stoves and boilers in Europe, but only exists in boilers in the U.S., and considerably of it is imported from Europe. (Click right here for PDF that involves this chart and some discussion of these concerns.)
In November 2014, Brookhaven Lab will be screening automated stoves and prototypes at a stove layout workshop to see how efficient they are. Their designers aspire to be portion of a actual craze of cleaner, much more automatic household wood heating. But can they do it at an affordable price stage? And, are consumers completely ready for them? Below, we will seem at stoves with automatic characteristics that are presently on the marketplace.
|A bi-metal coil functions as a warmth-
delicate thermostat which can partly
management the opening and closing of the damper.
1. The bi-steel coil. The oldest type of automation of steel wood stoves is the bi-metal coil which has been employed on scores of stove types and is now largely just utilised by a couple of catalytic stove makers, principally Blaze King and Vermont Castings. Some of the new automated functions do something related as the bi-metallic coil, but possibly do it significantly much better. A bi-steel coil is simply a thermostat run by a metal coil that can shut a damper down when its genuinely hot, and open up it up when its cooler. The stove’s air inlet can nevertheless be operated manually, but the bimetal coil will alter the air inlet more. They have a tendency to not perform nearly as effectively on non-cat stoves, because the temperatures in a non-cat firebox can be much more unpredictable, and if the coil shut down the air, or opened it too significantly, the stove would work improperly – and critically – it adds far way too a lot uncertainty in passing the EPA emissions certification take a look at.
|The rotating cause mechanism in the
Smartstove Selection by Englander
reduces air circulation once the stove is hot.
2. The up coming three stoves – the England Smartstove, the Quadrafire and the Travis – all use diverse automated approaches to beginning the fireplace quicker and with fewer emissions. Right after the start-up period of time, the stove operates like any other. The Smartstove by England Stove Performs was exhibited at the Wood Stove Decathlon on the National Shopping mall in 2013, but it was even now in growth so it was not element of the competitiveness. The stove has an “automatic air setback mechanism” which is a major air control with a rotating trigger which controls the opening and closing of air vents. When the operator begins a hearth, they provides the stove highest air and sets the set off. When the stove will get scorching enough, the bring about releases and principal air is lowered, while still delivering sufficient secondary air.
|Quadrafire’s Explorer two Commence-Up air
handle aids give the stove a lot more
air in the initial twenty five minutes.
3. Another current arrival on the marketplace is Quadrafire’s Explorer II, which appears to provide comparable automation. The website states “Automatic Combustion Control-offers the fire with air when it is most essential-major to lengthier burns.” A marketing and advertising video states the operation is so simple that all you have to do is “load the wooden, light the fireplace and wander away.” In accordance to the installation manual, ACC is generally a timer which the operator should manually initiate with a manage mechanism. In essence, it opens the front air channel which enables air to enter for twenty five minutes prior to closing. As soon as the entrance air channel is closed, manual controls are used to deliver preheated air to the prime of the firebox to burn off the relaxation of the unburned gases in the remaining 3 combustion zones.The Alliance confirmed with a company representative that no sensors are used or essential following the operator sets the timed management system.
|The slider on the Cape Cod
adjusts the charge of burns.
four. Travis industries Hybrid-Hearth technology™ created an automated “Greenstart” which shoots 1,four hundred degree air into the firebox for fifteen minutes to start your fireplace, or when you reload. The Greenstart can significantly lessen start-up emissions, and emissions in the course of reloading on a lower temperature mattress of coals, by jumpstarting the start-up approach and heating the wooden up more rapidly than it would with newspaper. Soon after the 1st fifteen minutes, the stove has no automated features, but some of the Travis stoves that use catalysts are amid the cleanest in the sector. The Travis Cape Cod stove won 2nd prize in the Wood Stove Decathlon.
5. The Nestor Martin’s Efel has an “automatic mode” that can keep the area at a wanted temperature. Or in timer method, it can alter the area temperature at a pre-set time. The stoves uses a basic ambient air thermostat in a distant management unit that you can function from the sofa or anyplace nearby. If you do not use it in automatic manner, the remote handle enables the person to modify the depth of the fire just as you would with a guide air management. One of the essential things that distinguishes this Efel from genuinely automatic stoves is that there are no sensors in the stove that can avoid the stove from smoldering or override an adjustment by the operator that would make the fireplace smolder.
|HWAM’s Autopilot technologies utilizes
sensors, alongside with a bi-metallic spring to
control combustion temperatures.
6. The last two stoves are far more completely automated stoves and are on the industry in Europe, but not in the US. Danish organization HWAM, whose automation will be third-party examined and assessed at Brookhaven Lab in November, has built-in a new patented system-Autopilot. Alongside with the Austrian Rikatronic, described below, the Hwam is one particular of the most sophisticated and totally automated stoves in Europe. HWAM 3630 IHS attributes a management method that electronically steps combustion situations through the use of a lambda oxygen sensor and a thermocouple. An onboard personal computer then allocates combustion air by way of three individual valves to assist the customer achieve the very same outcomes at home that are obtained in check labs underneath perfect situations. According to the Danish Technological institute, HWAM stoves with this system are 17% more effective and make 40% a lot more heat.
7. There are many variations of the Rikatronic wooden heater program. The Fox II stove attributes manual and automatic control settings. In manual method the air distribution can be managed in every combustion stage-even in the function of a electrical power outage. Automation in Rikatronic technological innovation functions with a microprocessor-controlled motor and flame temperature sensor which operates the RLS air distribution method. Airflow in every of the 5 combustion zones is properly modified for productive burn off. A purple mild indicates the ideal time to reload the stove. You can established the space temperature you want and once the needed space temperature is arrived at, you can activate the eco manner by urgent the Rikatronic³ button. This brings about the air offer to be optimally controlled to maintain the hearth for as long as possible, without having smoldering, and to go away powering as small ash as possible. Power use is two – four watts.
The initial 5 stoves described here signify American improvements that can partially decrease extreme wooden smoke, although the very last two stove from Europe signifies a far more holistic strategy that can support lessen emission not just in the start up, but all through the melt away cycle.  They are all still fairly new systems and we are likely to see a lot more companies boost upon them in coming many years.
The effort led by the International Alliance for Clear Cookstoves is an exceptional design of cooperative R&D, funding and training. It is time we develop a similar model for warmth stoves.
|Georgia (formerly USSR)
|South Ossetian Autonomous Oblast
St. Petersburg, Russia