There are other stoves just as efficent as blazeking just for the record. But yes you are correct. The claims some make about rocket mass heaters are absurd. There simply isn't enough btus in the amount of wood they are talking about
New Technology
- Thread starter bundy150
- Start date
-
Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.
We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.
We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
EbS-P
Minister of Fire
Here is the current complete EPA list of non catalytic stove with efficiency HHV 75% and higher. Its really short. I don’t see anything being cost competitive with anything already on the market. Realistically unless regulations mandate efficiency gains the average, call them a 5 cord a year burner, would be cost time ahead to keep a 70-80% stove running.
| New | Model | Manufacturer | Firebox Volume | Emission Rate (grams/hr) | Heat Ouput Range (BTUs) | Heat Output Upper (BTUs) | Heat Output Lower (BTUs) | Efficiency | Type | Subtype | Fuel Type | Test Method | CO | NSPS Compliance 2020 | Complance Date |
| 7110 B | Morso Jernstoberi A/S | 0.83 | 1.1 | 36554-16457 | 36554 | 16457 | 75 | Wood Stove | Non-Catalytic Stove | Cord Wood | 0.7 | Yes | 11/20/2019 | ||
| 6140 B, 6143 B, 6148 B, and 6170 B | Morso Jernstoberi A/S | 0.505 | 0.67 | 38107-15043 | 38107 | 15043 | 77 | Wood Stove | Non-Catalytic Stove | Cord Wood | 0.6 | Yes | 12/19/2019 | ||
| 21M-ACC-C, Discovery-1- | Hearth and Home Technologies | 1.48 | 1.7 | 29322-13585 | 29322 | 13585 | 76 | Wood Stove | Non-Catalytic Stove | Crib Wood | 1.5 | Yes | 02/28/2020 | ||
| Vermont Castings Dauntless FlexBurn Model | Hearth and Home Technologies | 1.82 | 1.1 | 49428-12252 | 49428 | 12252 | 77 | Wood Stove | Non-Catalytic Stove | Cord Wood | 2.39 | Yes | 02/23/2020 | ||
| Charnwood Skye E700 | A. J. Wells and Sons LTD | 0.82 | 2.5 | 31943-11128 | 31943 | 11128 | 78 | Wood Stove | Non-Catalytic Stove | Cord Wood | 1.1 | Yes | 05/29/2020 | ||
| 2B Standard 2020 | Morso Jernstoberi A/S | 0.69 | 0.55 | 25299-6959 | 25299 | 6959 | 80 | Wood Stove | Non-Catalytic Stove | Cord Wood | 0.38 | Yes | 07/30/2020 | ||
| Pleasant Hearth Large Wood Stove GWS-2200, GWS-2200-B, WSL-2200, WSL-2200-B, LWS-2200, WS-2200, WS-2200-B, PH2200WS, PH2200WS-B, SWS-2200, SWS-2200-B, HWS-2200, HWS-2200-B, PWS-2200-B | GHP Group | 2 | 1.5 | 70045-16394 | 70045 | 16394 | 75 | Wood Stove | Non-Catalytic Stove | Cord Wood | 1.937 | Yes | 08/21/2020 | ||
| Aspen C3 | Vermont Castings | 1.25 | 2 | 20086-17439 | 20086 | 17439 | 75 | Wood Stove | Non-Catalytic Stove | Crib Wood | 1.61 | Yes | 06/25/2019 | ||
| Evergreen | Travis Industries, Inc | 2.2 | 1.5 | 70720-12772 | 70720 | 12772 | 77 | Wood Stove | Non-Catalytic Stove | Cord Wood | 1.8 | Yes | 11/18/2018 | ||
| Farringdon 16 | ARADA STOVES Ltd. | 1.5 | 27025-8928 | 27025 | 8928 | 77 | Wood Stove | Non-Catalytic Stove | Crib Wood | 0.91 | Yes | ||||
| Polaris, Centauri, Vega, Sirius, Antares and Rigel | J. A. Roby Inc. | 1.4 | 20841-11759 | 20841 | 11759 | 76 | Wood Stove | Non-Catalytic Stove | Crib Wood | 0.76 | Yes | 03/30/2016 |
That's interesting and does that mean that my new wood stove Sirius is okay and good in comparing it to the rest of those stoves..I hope so...clancey
SpaceBus
Minister of Fire
Wow, that Morso 2b is amazing! I'm not just saying that because I have one either.
EbS-P
Minister of Fire
It is very impressive that they have almost every stove in their line on that list. I wonder how much of the efficiency is related to less mass to heat. The 2b only 75 Kg ( did I read that correctly?). Gets that heat into the room quickly and with such a small fire box that might be important.
Evan
SpaceBus
Minister of Fire
I think my 2b Classic is some 275 lbs, a featherweight for a wood stove for sure. I've been amazed at how much heat it can get out of the softwoods we usually burn. Even with the tiny firebox I can fit a good 20 lbs of hardwoods and that will get us through the night no problem. I've always been skeptical of the 83% efficiency rating for the 2b Classic, but maybe they were right.
It would be interesting to virtually take a 2B apart. I dont own one so Spacebus will have to fill in the details so some of this is conjecture. Light weight means high quality thin wall castings. Thin wall means the heat in the stove rapidly gets transferred to the room. A small firebox probably encourages smaller splits and fast burns. I have not seen anyone represent a 2B as a whole house heater or all night burn.. My guess is the test is optimized to match the Morso's design which is relatively fast hard burns. One of the concepts for small Euro stoves was dont expect to heat up the whole house, Sleep cold, get up and start a fast fire that throws heat in the room quickly. Get the space warm, get dressed and head out and let the fire burn out. Start it up again in the evening. Throw in proper air management where air goes to where it needs to be and route the air behind a thin baffle and preheat it so that its hot when it it gets to the combustion zone and you have a fairly clean stove.
The other niche for small stoves is superinsulated near zero homes with passive heating from sunlight. Modern Passivhaus designs incorporate interior thermal mass so the effects of a hot fast fire get buffered by the mass. All those cool surfaces suck in the heat and then release it back slowly. They don't need much heat to begin with so they go with the smallest stove they can find.
This goes against the "feed it and forget it" approach where pounds of wood are optimally packed into every inch of firebox and large split sizes are used to stretch out the burn even longer. That long slow burn approach optimized for long 24/7 burns is contrary to getting a clean burn so that is where things internal to the stove have to get complicated.
The approach for small stoves is If someone needs more heat, light another stove or swap in a larger one. One of my former professors was a big fan of owning two stoves, a small one and a large one. The small one gets used in shoulder season and the larger one gets used in the colder winter season. I have seen folks with setups where they can swap stoves in 20 minutes. The unused stove just gets moved back and its a planter and a source of mass to absorb heat.
The other niche for small stoves is superinsulated near zero homes with passive heating from sunlight. Modern Passivhaus designs incorporate interior thermal mass so the effects of a hot fast fire get buffered by the mass. All those cool surfaces suck in the heat and then release it back slowly. They don't need much heat to begin with so they go with the smallest stove they can find.
This goes against the "feed it and forget it" approach where pounds of wood are optimally packed into every inch of firebox and large split sizes are used to stretch out the burn even longer. That long slow burn approach optimized for long 24/7 burns is contrary to getting a clean burn so that is where things internal to the stove have to get complicated.
The approach for small stoves is If someone needs more heat, light another stove or swap in a larger one. One of my former professors was a big fan of owning two stoves, a small one and a large one. The small one gets used in shoulder season and the larger one gets used in the colder winter season. I have seen folks with setups where they can swap stoves in 20 minutes. The unused stove just gets moved back and its a planter and a source of mass to absorb heat.
Last edited:
As far as I can tell, the Pleasant Hearth stoves listed are vaporware. Their website makes inflated 80% efficiency claims, but does not have the manuals or required EPA testing documentation. The webpage says they are sold via Amazon and Walmart, but there are no Pleasant Hearth woodstoves on those sites now. A click on links for each stove takes you to an Oops, can't find it page.
SpaceBus
Minister of Fire
The Morso can only go 8 hours between burns if you want to relight on coals, that's probably the max with softwoods, you can get a bit more time with hardwoods. The real heat output is really just for four hours, six with hardwoods. Our house is 1200 sqft saltbox with most of the house on the bottom, tall wall facing south by slightly southeast. We have four sliding glass doors on the south side, no windows on the north side, and a few on the east and west. The only large window in the house is a fairly large 3'x4' three window casement set that faces right at the rising sun. Originally the house was sided in cedar lapsiding, 1/2" cdx, and 2x6's with R23 fiberglass insulation, the roof/attic insulation is two layers of R23. The Morso is a whole house heater in our situation, but in most it certainly would not be. We let the house cool down to near 65 by morning and then when I wake up I light a new fire in the Morso, usually just on the coals from the night before depending on how long we slept. Even cold starts are a non issue and the stove lights fairly easy with dry wood. Now that it is shoulder season the stove is a bit more balky, but our chimney is less than ideal right now. The castings are indeed very high quality and not thick like far east Asian cast iron, like old VC stuff.
Speaking of, the house came with an OG Defiant I, but the fireback had started its inevitable descent into the firebox. I've had one conversation with the previous owner about this and he said something along the lines of "Oh that's fine" and I take it he never flipped the bypass, ever. The thermostatic flap was not even connected to the lever or anything.
Now that we have the cookstove I'm burning it more frequently than the Morso. It is rated at the same BTU output as the Morso, but it definitely is not as efficient and it does not heat the house as much, it is not a whole house heater, even in our small house. This is an advantage in our shoulder seasons and it still heats our DHW and I love cooking on it, win win for me.
EbS-P
Minister of Fire
I could not find any of the model numbers listed in a quick search. And then there is the JA Robi that was tested in 2016??? Either they were way ahead of the curve or something else.
Evan.
BKVP
Minister of Fire
Oh boy!
1) All the manufacturers recognize, that 83% HHV and higher is problematic. As we build cleaner, more efficient wood stoves and inserts, we increase efficiency and create lower stack heat loss. The problem is, we are making them more draft sensitive. Is the future of a wood stove tied to a power-vent design? Much like high efficiency water heaters, pellet stoves and other products.
2) Point of diminishing return, as part of the NSPS promulgation, the cost of emissions reduction in relationship to the health benefit and consumer costs are evaluated.
3) I Don't See Smoke: 2.5 micron is not visible to the human eye unless an electron microscope is attached to that same eye. We often say 2.5 is the diameter of the average human hair, divided by 10 and then divided by 10 again. We now have stoves that are vastly cleaner burning than ever before. Millions of dollars in R & D have been pumped into this effort and as manufacturers we are cognizant of consumer interface with our appliances. (Education is critical!)
4) Regardless of the push by some for automation, solid research conducted in 2020 of thousands of wood stove users/consumers indicates the lions share of wood burners do not want electronics in their wood stoves. I can't tell you how many respondents scribed "if I wanted automation, I'd bought a pellet stove." So for the many of you in this thread that voiced that sentiment, thank you and it is known to us as manufacturers.
5) Bimetallic springs. Back in 1984 I was involved in the Thoroughbred horse racing industry. A far cry from the stove industry. However, after 25 years, I can say with 100% certainty the coil springs used in the 1980's into the early 1990's were "off the shelf" springs. I think I have shared before, we make our own springs from raw materials. Based upon the specific model, we cut the raw material to a exact length, place it into a die and form full or portions of full revolutions into that spring. That spring is then baked at a specific temperature, for a specific duration of time. Keep in mind, these are unit specific so we have a rather robust receipt book. The most secure place in this operation is that room!
6) Where we are headed....Industry sued EPA over one item from the 2015 NSPS. As an industry we are concerned about EPA's lack of written acknowledgement to the variability in wood stove emissions testing. Both inter lab and intra lab testing. So when EPA presented their case in the court, they took the position they included a 1 gr/hr. level of variability into the standard of 2.0 gr/hr. If this is true (which we certainly do not agree with) then the standard or target was 1.0 gr/hr.
Now all you answer this question: Do you want to buy stove company?
BKVP
7) I also meant to address the idea of powered catalyst. Although not integrated into original combustion designs, there have been a handful of aftermarket products. Each has failed miserably when placed into service. Most recently an attempt was made to use a computer control design interface unit on hydronic furnaces. The mfg of the device assured air regulators they would work. I saw them, a huge stack, in the office of the regulator.
8) ESP's were also part of a more recent study. Tested both in-situ and also in approved test lab, results were atrocious! In fact, one home sustained significant damage as a result of a fire. ESP's take time to become active (sound familiar?) and in several cases tremendous creosote formations developed.
There are a few designs, one attached at the termination and the other within the living quarters. Given that ESP's must be cleaned of deposits, the external units are not well suited to service with snow and ice on the roof.
Folks, mfgs have done a great job engineering clean burning stoves. User education is the single greatest influence on successful clean burning.
That is why this site and others are critical!
Keep it going....
BKVP
1) All the manufacturers recognize, that 83% HHV and higher is problematic. As we build cleaner, more efficient wood stoves and inserts, we increase efficiency and create lower stack heat loss. The problem is, we are making them more draft sensitive. Is the future of a wood stove tied to a power-vent design? Much like high efficiency water heaters, pellet stoves and other products.
2) Point of diminishing return, as part of the NSPS promulgation, the cost of emissions reduction in relationship to the health benefit and consumer costs are evaluated.
3) I Don't See Smoke: 2.5 micron is not visible to the human eye unless an electron microscope is attached to that same eye. We often say 2.5 is the diameter of the average human hair, divided by 10 and then divided by 10 again. We now have stoves that are vastly cleaner burning than ever before. Millions of dollars in R & D have been pumped into this effort and as manufacturers we are cognizant of consumer interface with our appliances. (Education is critical!)
4) Regardless of the push by some for automation, solid research conducted in 2020 of thousands of wood stove users/consumers indicates the lions share of wood burners do not want electronics in their wood stoves. I can't tell you how many respondents scribed "if I wanted automation, I'd bought a pellet stove." So for the many of you in this thread that voiced that sentiment, thank you and it is known to us as manufacturers.
5) Bimetallic springs. Back in 1984 I was involved in the Thoroughbred horse racing industry. A far cry from the stove industry. However, after 25 years, I can say with 100% certainty the coil springs used in the 1980's into the early 1990's were "off the shelf" springs. I think I have shared before, we make our own springs from raw materials. Based upon the specific model, we cut the raw material to a exact length, place it into a die and form full or portions of full revolutions into that spring. That spring is then baked at a specific temperature, for a specific duration of time. Keep in mind, these are unit specific so we have a rather robust receipt book. The most secure place in this operation is that room!
6) Where we are headed....Industry sued EPA over one item from the 2015 NSPS. As an industry we are concerned about EPA's lack of written acknowledgement to the variability in wood stove emissions testing. Both inter lab and intra lab testing. So when EPA presented their case in the court, they took the position they included a 1 gr/hr. level of variability into the standard of 2.0 gr/hr. If this is true (which we certainly do not agree with) then the standard or target was 1.0 gr/hr.
Now all you answer this question: Do you want to buy stove company?
BKVP
7) I also meant to address the idea of powered catalyst. Although not integrated into original combustion designs, there have been a handful of aftermarket products. Each has failed miserably when placed into service. Most recently an attempt was made to use a computer control design interface unit on hydronic furnaces. The mfg of the device assured air regulators they would work. I saw them, a huge stack, in the office of the regulator.
8) ESP's were also part of a more recent study. Tested both in-situ and also in approved test lab, results were atrocious! In fact, one home sustained significant damage as a result of a fire. ESP's take time to become active (sound familiar?) and in several cases tremendous creosote formations developed.
There are a few designs, one attached at the termination and the other within the living quarters. Given that ESP's must be cleaned of deposits, the external units are not well suited to service with snow and ice on the roof.
Folks, mfgs have done a great job engineering clean burning stoves. User education is the single greatest influence on successful clean burning.
That is why this site and others are critical!
Keep it going....
BKVP
Yes, but it also means you should have stuck with the Morso 2B that I suggested. LOL! Sorry...couldn’t resist. Your choice of stove will be just fine. If you’re happy with it, then we’ll all be happy for you.
Would you care to elaborate on point #5?
Are you referring to “off the shelf” coil springs used in “BK stoves” in the 80’s and 90’s, or other stoves.
I absolutely agree...I do not want automation into a wood stove or I might as well buy a pellet stove. Doesn’t get anymore simple than a spring coil and they perform flawlessly and nearly without fail. When they do fail, by design, they are safe.
They perform flawlessly if the system is run and designed properly. Unfortunately very few stoves that have them are designed very well. I actually prefer controlling it myself. But that is just my opinion. The bk I am using does put out great even heat because of it
Preferring to control a stove manually is just that, a preference for some people. Part of running a stove the old time way. I get that. It’s something I enjoy as well, but a stat can quickly spoil you at times...times when you need to leave home quickly and/or focus on something else.
Which ones have them that you think aren’t designed very well?
Of course that's what stove owners would say, because any user that wants a more automated system doesn't own a wood stove, because that technology is not available in the marketplace.
There's a reason most of us have some form of central heating, because it provides reliable heat with little user intervention. Now a small segment of these users own automated hydronic wood boilers, because they want the benefits of central heat with the advantages of using wood as a fuel. Whether wood is the choice of fuel because of cost, availability, or limited availability of other fuels is different in every use case. Now imagine that same concept except with a heating system 1/4 the cost of a hydronic setup. That would be the automated wood stove, this would open the door to many more and new stove owners because the economics pencil out better with a lower initial cost.
The fact is the cost of traditional heating is going up, Canada has a carbon tax that will more than double the cost of heating with fossil based fuels, I expect the US to implement a similar policy anytime. Many more consumers will be exploring wood heat as a method of reducing these costs, maybe similar to the 70's rush to wood heating, especially considering the off-grid lifestyle that many millennials are hoping to achieve when they become homeowners. The problem is these people are more inclined to purchase an appliance that comes with a phone or computer based app rather than learn to operate a manual control lever.
I come from more of a powersports background, and there's always a group (sometimes a large one) that is resistant to change. Fuel injection on 2-stroke snowmobile engines was one of these topics, many were very opposed to "complicated, unreliable electronics" being installed on new snowmobiles. After a while the nay-sayers quieted and disappeared altogether, and to this day I've never heard someone say "man I really miss re-jetting my carb 3 times a day". Same thing happened with snowmobile turbos, lots said "you can't turbo a 2-stroke", or "it won't last 2 minutes", some of these comments from the OEM's themselves, and at first they were right. But about 15 years ago with fuel injection and proper fuel control turbos became feasible and mostly reliable from aftermarket companies, and many of these companies did well selling a product the OEM's wouldn't. Finally 2 years ago Ski-Doo came out with the first factory turbo, and Polaris will for this winter, and guess what? Every turbo they have built has been sold, most before they even landed at dealers, and from my understanding almost every pre-order unit available for the coming winter is also sold.
I'm not trying to be argumentative, but rather present a view point that isn't heard, because I believe there is a large number of potential customers that completely pass on wood heat because of the lack of technological/digital innovation that they are accustomed to in other portions in their lives.
The most dangerous phrase in business is, "we've always done it this way".
One of the big draws of wood heat for me is the ability to run in a power outage. Electronics have issues without electricity.
Running through a power outage does not need to be an issue. Its matter or economics, thermoelectric generators are old tech that can generate enough power to run a few control loops in a stove. Not very practical if there needs to be ID of FD fan but they are solid state and just about bombproof. It just adds some cost to the stove for a feature that is rarely if ever used. Bimetallic springs are also bombproof but my guess is a couple of electrically driven PID control loops working with feedback sensors would improve the efficiency and emissions. over a bimetallic.
Of course adding advance electronics introduce the serviceability aspect. https://www.wired.com/story/they-hacked-mcdonalds-ice-cream-makers-started-cold-war/
Of course adding advance electronics introduce the serviceability aspect. https://www.wired.com/story/they-hacked-mcdonalds-ice-cream-makers-started-cold-war/
BKVP
Minister of Fire
I'll be discreet and say we sold generic springs out of our facilities (6 in US) and 1 in Canada to many, many mfgs.
BKVP
Minister of Fire
I don't take exception to anything you wrote. Fact is, most (over 60%) cut their own firewood. They touch it, haul it, smell it, stack it and load. Automation won't preclude any of this. So the user has done all the work. If the user is educated on proper use and maintenance and how the combustion of wood takes place, the stove will burn clean, last a very long time and even work when power goes out. (Texas is our fastest growing state Q1 this year). In an automated unit, if power is needed a back up power system would be advisable. If a thermocouple or O2 sensor goes out, stop burning (for many not an option) cool stove and call in a technician to work or repair or replace it. To be fair, most people in fact have back up systems they can use....if there is power.
Having knowledge and the ability to make things work under pressure can be most rewarding. Look at how clever, informed people proved this in TX.
Can you recall the actual phone numbers of the top 5 or ten people you call most often?
In an emergency you can't find your phone or your battery is dead. Your in the middle of the biggest city....a bystander allows you to use their phone....but technology has rendered us unable to recall those very important numbers. As a grandfather who had to experience a 9 year old being loaded on a helicopter for an emergency last week, I was unable to recall numbers and my phone was at home.
Technology is wonderful where needed. I suspect more of the potential wood burners you identified would buy a wood stove if all the work I mentioned above was done for them.
As for costs of heating/taxes etc., you're spot on. I have a central heat system, earn a good wage but just yesterday I was looking up at the Blue Mountains wondering if enough snow had melted to get cutting.
Different strokes for different folks. Thank you for your contribution to this and other threads....
BKVP
And yes that highly technical helicopter got her to the expert practitioners she needed to save her....Thank you Lord!
BKVP
Minister of Fire
SpaceBus
Minister of Fire
I always made my soldiers keep a full 8x11 sheet of paper full of unit phone numbers, both cell and land lines, on their person at all times. That call roster saved my butt a few times!
Was that because BK bought the rights to sell such a product to other wood stove manufacturers and they may have perfected how to incorporate them better for wood stove use?
It’s not like they were the first ‘stove company’ to use them because they were used successfully on stoves approximately 40 years prior to BK becoming a company.
“For modern wood burning stoves” you can’t take anything away from BK, but I do know there are companies that specialize in producing these coil springs for various industries and it seems unlikely that BK alone would be the sole perfectionists of such a product.
Obviously BK could produce their own springs tailored to their stoves specifically, but that hardly makes any sense to focus on that when these have been made for various things far longer than BK has been around. Much too easy to find one that works, duplicate it or have it made by someone else, and then figure out how to incorporate it into a cleaner burning stove...which would make more sense...to focus on building a cleaner burning stove by using someone else product, rather than producing it themselves.
I’ve spent a fair amount of time in manufacturing myself and that just doesn’t make sense...especially when the idea is much older than the company itself.
Not doubting you, or trying to make you out as a liar, so I hope you don’t take it that way. Just trying to put some pieces of a puzzle together that’s all. Obviously, BK has used the bi-metallic springs to their advantage and I think they are great. So great, I think, aside from automation as has been discussed, that the next best alternative to making all stoves more efficient is the use of bi-metallics.
The bi metallic coil isn't what makes blazekings efficent. It is what gives them consistent temp and long burn times. And it does allow them to burn efficently while doing that. But several other companies have reached the same efficency without thermostatic control. The efficency comes from design and engineering.
As far as manufacturing springs for other companies why wouldn't it make sense? They are set up to manufacturer them and other companies were buying off the shelf components already so why shouldn't bk capitalize on that and manufacturer them for other companies? If it makes financial sense to all involved I don't see why it is surprising. By setting up to manufacturer them they get complete control over what goes into their product and get to also make a profit selling stock ones to other companies. It is a win win for them
Last edited:
Similar threads
