UL listed pellet rocket mass heater

[EatenByLimestone]

So this popped into my youtube feed today. It's a steel rocket stove that claims to be UL listed. The review is a horrible one, but it interested me enough to do some research.

I checked out other similar stoves to see how it is probably built. It takes kindling and lots of air to achieve a very hot burn. This can be a clean burn. Ok, but where traditional high mass masonry rocket heaters and masonry stoves transfer that heat to the mass, this stove weighs only 160lbs or so. It's going to be needing fuel constantly or it will rapidly cool off. It's not going to radiate that heat back for hours like more traditional masonry based stoves would.

What is the draw? A 1cu ft box store stove will have a longer burn time, higher thermal mass, burn larger wood, a view of the fire, the list can go on and on. What am I missing? I don't understand the draw.

 

[EbS-P]

It’s all in the title, the draw that is. “Let me show you this stove burning 3 pieces of paper and a handful of twigs and not hook it up to any flue. He spent longer in Post production adding dimensions than he did
Giving any useful info. It’s a fad. They don’t even have the manual in the website. It 404s. Could you imagine the mountain of twigs and branches you would need if you had to burn the equivalent of 3 cords through this thing. Just my thoughts. Oh and who has an outlet at that height. Good it’s ugly. And BTW. Copied this from their website.

1. Burns wood pellets with over 99% combustion efficiency once fully lit.​

what is combustion efficiency?​

 

[rocketheater]

So this popped into my youtube feed today. It's a steel rocket stove that claims to be UL listed. The review is a horrible one, but it interested me enough to do some research.

I checked out other similar stoves to see how it is probably built. It takes kindling and lots of air to achieve a very hot burn. This can be a clean burn. Ok, but where traditional high mass masonry rocket heaters and masonry stoves transfer that heat to the mass, this stove weighs only 160lbs or so. It's going to be needing fuel constantly or it will rapidly cool off. It's not going to radiate that heat back for hours like more traditional masonry based stoves would.

What is the draw? A 1cu ft box store stove will have a longer burn time, higher thermal mass, burn larger wood, a view of the fire, the list can go on and on. What am I missing? I don't understand the draw.

We build our heaters at our factory in Bourbon, MO. We're listed to UL-1482, ULC-S627, and ASTM-E 1509 standards. Our stoves are built different than the ones you commonly see online. We use a combination of American steel, high-temperature insulation, and refractory ceramic paint. It takes about a minute with a blow torch to start the fire and typical pellet burns last between 8 to 20 hours. Using wood sticks, cordwood, etc., the base heater will only burn for about 30 to 60 minutes. In effect, this is a pellet stove that doesn't lock you into pellets entirely, and it can burn softwoods without creosote issues. Our manual describes integration into thermal mass, which if an owner decides to install with thermal mass obviates a lot of these legitimate and would be disadvantages. We do not sell thermal mass integration because it doesn't make sense to ship tons of firebrick, sand, clay, etc. when these items are typically available locally for a much lower cost. You are correct about the advantages of a 1 cu foot stove; however, it achieves a lower overall peak temperature at the plume zone of combustion, thus does not achieve as high of a combustion efficiency. Combustion efficiency is simply a measure of how many combustible gases are produced and contrasting that with the amount that is actually bonded with oxygen to burn. If you have 1,000 parts combustible gas molecules, and 995 of those molecules bond with oxygen, then you have a 99.5% combustion efficiency. We have achieved a 99.5% combustion efficiency according to an independent EPA certified lab. I consider this to be acceptable performance, given that Space X's raptor engine, which is a methane and liquid oxygen burning rocket engine, has a 98% combustion efficiency, and we are achieving 1.5% higher than that using atmospheric air (which is roughly 80% nitrogen) and wood pellets. Ultimately the draw is a gravity fed non-electric pellet stove, that is leagues ahead more efficient than any other gravity fed pellet stove, and can also burn wood in a pinch, and optionally be integrated into thermal mass making it a true building code and insurance policy compliant rocket mass heater. Glass doors and other features is something we are working on. The owners manual is attached below.

 

[bholler]

We build our heaters at our factory in Bourbon, MO. We're listed to UL-1482, ULC-S627, and ASTM-E 1509 standards. Our stoves are built different than the ones you commonly see online. We use a combination of American steel, high-temperature insulation, and refractory ceramic paint. It takes about a minute with a blow torch to start the fire and typical pellet burns last between 8 to 20 hours. Using wood sticks, cordwood, etc., the base heater will only burn for about 30 to 60 minutes. In effect, this is a pellet stove that doesn't lock you into pellets entirely, and it can burn softwoods without creosote issues. Our manual describes integration into thermal mass, which if an owner decides to install with thermal mass obviates a lot of these legitimate and would be disadvantages. We do not sell thermal mass integration because it doesn't make sense to ship tons of firebrick, sand, clay, etc. when these items are typically available locally for a much lower cost. You are correct about the advantages of a 1 cu foot stove; however, it achieves a lower overall peak temperature at the plume zone of combustion, thus does not achieve as high of a combustion efficiency. Combustion efficiency is simply a measure of how many combustible gases are produced and contrasting that with the amount that is actually bonded with oxygen to burn. If you have 1,000 parts combustible gas molecules, and 995 of those molecules bond with oxygen, then you have a 99.5% combustion efficiency. We have achieved a 99.5% combustion efficiency according to an independent EPA certified lab. I consider this to be acceptable performance, given that Space X's raptor engine, which is a methane and liquid oxygen burning rocket engine, has a 98% combustion efficiency, and we are achieving 1.5% higher than that using atmospheric air (which is roughly 80% nitrogen) and wood pellets. Ultimately the draw is a gravity fed non-electric pellet stove, that is leagues ahead more efficient than any other gravity fed pellet stove, and can also burn wood in a pinch, and optionally be integrated into thermal mass making it a true building code and insurance policy compliant rocket mass heater. Glass doors and other features is something we are working on. The owners manual is attached below.

How would adding mass effect the ul listing of the stove

 

[stoveliker]

Molecules attaching to oxygen does not make combustion efficient. At the very least you don't understand the chemistry here.

All creosote has actually partially burned. I.e. it partially oxidized. I.e. it "attached to an oxygen molecule". The point is that most constituents of fuel need way more than one oxygen molecule.

Claiming efficiency like this is a huge red flag for me.

 

[bholler]

We build our heaters at our factory in Bourbon, MO. We're listed to UL-1482, ULC-S627, and ASTM-E 1509 standards. Our stoves are built different than the ones you commonly see online. We use a combination of American steel, high-temperature insulation, and refractory ceramic paint. It takes about a minute with a blow torch to start the fire and typical pellet burns last between 8 to 20 hours. Using wood sticks, cordwood, etc., the base heater will only burn for about 30 to 60 minutes. In effect, this is a pellet stove that doesn't lock you into pellets entirely, and it can burn softwoods without creosote issues. Our manual describes integration into thermal mass, which if an owner decides to install with thermal mass obviates a lot of these legitimate and would be disadvantages. We do not sell thermal mass integration because it doesn't make sense to ship tons of firebrick, sand, clay, etc. when these items are typically available locally for a much lower cost. You are correct about the advantages of a 1 cu foot stove; however, it achieves a lower overall peak temperature at the plume zone of combustion, thus does not achieve as high of a combustion efficiency. Combustion efficiency is simply a measure of how many combustible gases are produced and contrasting that with the amount that is actually bonded with oxygen to burn. If you have 1,000 parts combustible gas molecules, and 995 of those molecules bond with oxygen, then you have a 99.5% combustion efficiency. We have achieved a 99.5% combustion efficiency according to an independent EPA certified lab. I consider this to be acceptable performance, given that Space X's raptor engine, which is a methane and liquid oxygen burning rocket engine, has a 98% combustion efficiency, and we are achieving 1.5% higher than that using atmospheric air (which is roughly 80% nitrogen) and wood pellets. Ultimately the draw is a gravity fed non-electric pellet stove, that is leagues ahead more efficient than any other gravity fed pellet stove, and can also burn wood in a pinch, and optionally be integrated into thermal mass making it a true building code and insurance policy compliant rocket mass heater. Glass doors and other features is something we are working on. The owners manual is attached below.

Are your stove EPA 2020 approved? I couldn't find them on the list

 

[EbS-P]

So I understand combustion efficiency, however in the heater heating industry I feel that when an efficiency is talked about it refers to the heating efficiency. That’s what the user should care about. Should I care about the combustion efficiency? are current epa 2020 stoves about the same or much less?

 

[EatenByLimestone]

thank you for replying to the post. You give us a chance to ask questions and get answers vs speculate.

On the gravity fed pellet hopper system, it seems like the burn pot would quickly fill with ash and embers, possibly leading to fire working it’s way up into the hopper. The design of the system looks like it could act like a chimney, further complicating matters since all the flame and combustion products would be going right into your fuel source. It seems like this would be needing attention constantly to keep it clear. Am I missing something?

 

[Poindexter]

I have built several rocket stoves, mostly posted on permies back in the day. The thing being sold, other attributes aside, is just the metal burner, the tricky engineering.

The next step is to integrate the ready made burner of steel into something like a bench along the living room wall, but route the burner's exhaust gas through the mud or clay or adobe bench- and then vent it outdoors.

The idea is you run the stove a little while, the mud or adobe or clay gets heated by the exhaust gas, and then the mass, the clay bench, gives off heat into the living space for hours.

The efficiency is possibly there, at least with some designs under some conditions, but I simply could not possible cram enough wood into one to get out the BTUs I need in the house up here.

If we retire somewhere more temperate, I might build one on an outdoor patio to see about having a warm place to sit next to the firepit on a crisp autumn evening.

 

[EatenByLimestone]

Better review.

 

[stoveliker]

One of those videos again notes the 1/3 to 1/4th of the wood, which may only hold with respect to an old pre-EPA smoke dragon, not with respect to a modern 75-80-ish percent efficient (BTU in vs BTU out) stove.

 

[Poindexter]

Peter van den Berg

Peter van den Berg lives on the west coast of The Netherlands. He is a retired boat repairman, spending most of his time experimenting with masonry- and Rocket Stoves, and has been very active in t…

www.rocketstoves.com

 

[begreen]

Better review.
Not sold on either the aesthetics, nor the operation. It's not burning enough BTUS for a regular-sized house. Still, it maybe fun for the experimenter.

When asked about feeding it, this was the response:
"I have to feed it every half hour or so during the day unless I am burning pellets and the thermal mass bench keeps the house warm over night."

 

[EatenByLimestone]

The stove retails for $2500. For that price, I'd be choosing other options to heat. But I fully admit I might be missing something fundamental. I like tinkering with things, but every half hour would get old quick.

 

[Poindexter]

Depending on climate, it might make sense in a sunroom. You could run it maybe twice daily while youa re starting seeds, then once daily as the weather warms, move your vegetable plants outdoors for the summer... bring a few plants back in that are still bearing as first frost looms to get the last of the harvest off them with once daily burns.

 

[stoveliker]

I think they have their place, as noted before. Especially when using large thermal mass.

But the comparison is always (has to be) to old inefficient stoves. The group of fanboys for this type of heaters does make inappropriate comparisons. (1/4 of the wood for my old stove..)

Also the above noted combustion efficiency is not, cannot be correct. And is described incorrectly.

I read that text from the dutch guy. The approach makes sense, and it's nice to be able to run on twigs. But given my BTU needs, I would not want to collect fuel in twig form.

Shop, sunroom heaters may be nice. Home heaters, not like this. The you'd have to have the thermal mass, and the person being home for a few hours to be able to input enough BTUs that can heat the home when released in a spread out manner.

 

[rocketheater]

How would adding mass effect the ul listing of the stove

Its fully compliant to integrating mass and tested and listed to be compatible with thermal mass. Details on how to do so are in the owners manual. Integrating a thermal mass bench is possible, it has been done before by several of our previous customers, and it can make the heater more efficient. As a stand alone unit, the heater is ideal as a pellet stove, and heats 2,000 square feet quire comfortably. A lot of our customers live in environments that are effectively devoid of sufficient biomass, so they import fuel pellets, or are physically unable to chop, stack, and season wood, so they use fuel pellets. This stove is not for everyone. It is, effectively, a pellet stove that does not need electricity, that does not lock you into pellets in that you can burn wood, so the heater is not entirely useless if fuel pellet supplie chains are completely disrupted, and is more efficient than any other gravity fed pellet stove on the market by a long shot. Attached below is a photograph of our previous Gen 1 heater integrated into thermal mass, making it into a true Rocket Mass Heater and a form of masonry heater.

I'm well aware that multiple oxygen atoms need to attach to the various volatile organic compounds to fully burn. We are talking about pareto efficiency here, X amount of combustibles, and in an perfect model, all possible oxides that could form, would form. This would be 100% efficiency. For example, methane is 1 carbon atom and 4 hydrogen atoms. The stoichiometric ratio assuming pure oxygen would be 4 oxygen atoms to one methane molecule. Two for the carbon, to form Co2, and another 2 for the hydrogen atoms, to form water. Of course, wood being a less than ideal fuel containing literally thousands of complex proteins, carbohydrates, cellulose, bio-tar, water moisture, various carcinogens, minerals including non-combustible minerals, and a whole slough of combustion and thermal by-products, coupled with atmospheric air which itself is far from pure, and achieving optimal combustion efficiency can be rather difficult. That we have achieved 0.38 grams per hour of solid particulate emissions, and average less than 10 parts per million of carbon monoxide at any given time, is acceptable to me, given that most natural gas forced air furnaces average approximately 20 parts per million of carbon monoxide.

The EPA updates their approval listing periodically. Come the next update cycle we should be on their public ledger. Attached below are the test results from the EPA lab. We have as far as I can tell and am aware of, the cleanest burning non-catalytic non electric burning heater, and the #3 overall lowest solid particulate emissions and an exceptionally low CO emissions. This is independent EPA certified lab testing. They used the 99.5% combustion efficiency. This was not a figure I derived using my own equipment or practices, as we only have an inexpensive gas flue analyzer available and thus use CO emissions an an analogy to optimize for a full dilution tunnel test as our small business can not afford an in house dilution tunnel. The higher heating value could be better, I will admit, but our exhaust gas temperatures are still fairly low when compared to a wood stove, albeit higher than an electrically fed pellet stove, as we must use some of the heater to induce draft up the chimney. We do have an identical HHV to the wiseway stove, within the margin of error, and are much cleaner burning at less than half the average weighted emissions. The HHV is also better than many pellet stove's on the market, falling in at about average for HHV efficiency. Which is actually fairly good when you consider than we dont use any algorithmic control boards, sensors, regulators, fans, augers to control feed, draft inducers, automatic igniters, heat exchangers, etc. and we can also burn wood when integrated as a mass/masonry heater, so we had to engineer and optimize the heater to burn cleanly, efficiency, and reliably with two very different fuels.

As far as backdrafting up the pellet feed tube, that was thoroughly tested and underwritten by Guardian Firetesting Labs and passed all their safety requirements outlined in UL and ASTM standards, which includes deliberately trying to force a jam, bridge, or blockade, and trying to induce a backdraft. The testing engineers were unable to force a backdraft, jam, or burn-back, despite deliberately attempting to induce those conditions. This design involved 7 years of active and expensive research and development which included materials science, metallurgy, computation fluid dynamic modelling, tested the coefficient of friction of various materials, and long term longevity testing, to achieve this threshold of reliability. Rheological and fluid modelling the flow of sand is notoriously difficult, and fuel pellets proved to be even more complicated. This was actually one of the main sticking problems when we first started development 7 years ago, and we thoroughly designed and optimized the feed system to completely obviate that previously systemic problem.

As far as cost, yes, it is expensive. We are also backordered through June and thus had to raise prices to prevent the backorder log from extending past an entire year as it did in Autumn of last year. Again, this heater is not for everyone. Its a pellet stove that can also burn wood, and is the only rocket heater that is listed to UL standards and building code compliant for thermal mass integration, which means everyone can now legally install a true rocket mass heater if they want a rocket mass heater in their home. Rocket mass heaters aren't for everyone, but there was a gap in the market as they work for many people, and for many people a rocket mass heater does work well with their lifestyle, so we developed a duel use heater that fits two mission profiles very well, gravity fed pellet stoves and building code compliant rocket mass heaters, with one product. It is also a pellet stove with a cooktop plate, which many (but not all) pellet stove's lack.

At the end of the day, we're not a huge company. Its just my father and I applying our engineering and fabrication skills to create value and bring more home and building heating options to people. We aren't the best at every mission profile, what we make isn't for everyone, but its worth considering for some people with specific desires or needs. It looks the way it does and is designed the way it is because we can only use the tools and machines available to us. We do not have fancy ornate cast iron pieces, or similar fancy hinged doors with ceramic fireglass, is because we do not have a 5 million dollar induction melting furnace and hydraulic sand pattern molding press to make heaters out of castings. We have a small welder, a plasma cutter, a small horizontal band saw, a small sheet metal brake, a small air compressor, and an old bridgeport milling machine. Thus we build what we can with the tools we have given what we have available to us. Maybe someday in the far flung future we will have a 5 million dollar induction furnace to make heaters out of recycled scrap iron, but that day is a long ways out. In the meantime, we have to weld them, thus they wont be winning any beauty pageants anytime soon. What I can tell is is that they are robust, American made heaters built and engineered to do their job with the unfaltering, unyielding, relentless reliability for decades at a time as used to be expected of all American manufactured products in a not so exceptionally bygone era, as was common of American industry. I took my personal job in engineering these heaters very seriously, as the designer I considered it my full obligation and duty to design these heaters to never fail, as lives are on the line, a single failure can lead to death in more than a few ways. I have done everything in my power and full scope of ability to ensure that does not happen, that the owners will stay warm, and that the heater will not clog, jam, or fail, or deteriorate via planned obsolescence (my personal arch nemesis, of which there is no other pattern of modernity I loathe more intensely).

Thank you all for the genuine questions, concerns, and wonderful comments. If there is anything else I can assists with or answer I would be elated to do so.

 

[bholler]

Its fully compliant to integrating mass and tested and listed to be compatible with thermal mass. Details on how to do so are in the owners manual. Integrating a thermal mass bench is possible, it has been done before by several of our previous customers, and it can make the heater more efficient. As a stand alone unit, the heater is ideal as a pellet stove, and heats 2,000 square feet quire comfortably. A lot of our customers live in environments that are effectively devoid of sufficient biomass, so they import fuel pellets, or are physically unable to chop, stack, and season wood, so they use fuel pellets. This stove is not for everyone. It is, effectively, a pellet stove that does not need electricity, that does not lock you into pellets in that you can burn wood, so the heater is not entirely useless if fuel pellet supplie chains are completely disrupted, and is more efficient than any other gravity fed pellet stove on the market by a long shot. Attached below is a photograph of our previous Gen 1 heater integrated into thermal mass, making it into a true Rocket Mass Heater and a form of masonry heater.

I'm well aware that multiple oxygen atoms need to attach to the various volatile organic compounds to fully burn. We are talking about pareto efficiency here, X amount of combustibles, and in an perfect model, all possible oxides that could form, would form. This would be 100% efficiency. For example, methane is 1 carbon atom and 4 hydrogen atoms. The stoichiometric ratio assuming pure oxygen would be 4 oxygen atoms to one methane molecule. Two for the carbon, to form Co2, and another 2 for the hydrogen atoms, to form water. Of course, wood being a less than ideal fuel containing literally thousands of complex proteins, carbohydrates, cellulose, bio-tar, water moisture, various carcinogens, minerals including non-combustible minerals, and a whole slough of combustion and thermal by-products, coupled with atmospheric air which itself is far from pure, and achieving optimal combustion efficiency can be rather difficult. That we have achieved 0.38 grams per hour of solid particulate emissions, and average less than 10 parts per million of carbon monoxide at any given time, is acceptable to me, given that most natural gas forced air furnaces average approximately 20 parts per million of carbon monoxide.

The EPA updates their approval listing periodically. Come the next update cycle we should be on their public ledger. Attached below are the test results from the EPA lab. We have as far as I can tell and am aware of, the cleanest burning non-catalytic non electric burning heater, and the #3 overall lowest solid particulate emissions and an exceptionally low CO emissions. This is independent EPA certified lab testing. They used the 99.5% combustion efficiency. This was not a figure I derived using my own equipment or practices, as we only have an inexpensive gas flue analyzer available and thus use CO emissions an an analogy to optimize for a full dilution tunnel test as our small business can not afford an in house dilution tunnel. The higher heating value could be better, I will admit, but our exhaust gas temperatures are still fairly low when compared to a wood stove, albeit higher than an electrically fed pellet stove, as we must use some of the heater to induce draft up the chimney. We do have an identical HHV to the wiseway stove, within the margin of error, and are much cleaner burning at less than half the average weighted emissions. The HHV is also better than many pellet stove's on the market, falling in at about average for HHV efficiency. Which is actually fairly good when you consider than we dont use any algorithmic control boards, sensors, regulators, fans, augers to control feed, draft inducers, automatic igniters, heat exchangers, etc. and we can also burn wood when integrated as a mass/masonry heater, so we had to engineer and optimize the heater to burn cleanly, efficiency, and reliably with two very different fuels.

As far as backdrafting up the pellet feed tube, that was thoroughly tested and underwritten by Guardian Firetesting Labs and passed all their safety requirements outlined in UL and ASTM standards, which includes deliberately trying to force a jam, bridge, or blockade, and trying to induce a backdraft. The testing engineers were unable to force a backdraft, jam, or burn-back, despite deliberately attempting to induce those conditions. This design involved 7 years of active and expensive research and development which included materials science, metallurgy, computation fluid dynamic modelling, tested the coefficient of friction of various materials, and long term longevity testing, to achieve this threshold of reliability. Rheological and fluid modelling the flow of sand is notoriously difficult, and fuel pellets proved to be even more complicated. This was actually one of the main sticking problems when we first started development 7 years ago, and we thoroughly designed and optimized the feed system to completely obviate that previously systemic problem.

As far as cost, yes, it is expensive. We are also backordered through June and thus had to raise prices to prevent the backorder log from extending past an entire year as it did in Autumn of last year. Again, this heater is not for everyone. Its a pellet stove that can also burn wood, and is the only rocket heater that is listed to UL standards and building code compliant for thermal mass integration, which means everyone can now legally install a true rocket mass heater if they want a rocket mass heater in their home. Rocket mass heaters aren't for everyone, but there was a gap in the market as they work for many people, and for many people a rocket mass heater does work well with their lifestyle, so we developed a duel use heater that fits two mission profiles very well, gravity fed pellet stoves and building code compliant rocket mass heaters, with one product. It is also a pellet stove with a cooktop plate, which many (but not all) pellet stove's lack.

At the end of the day, we're not a huge company. Its just my father and I applying our engineering and fabrication skills to create value and bring more home and building heating options to people. We aren't the best at every mission profile, what we make isn't for everyone, but its worth considering for some people with specific desires or needs. It looks the way it does and is designed the way it is because we can only use the tools and machines available to us. We do not have fancy ornate cast iron pieces, or similar fancy hinged doors with ceramic fireglass, is because we do not have a 5 million dollar induction melting furnace and hydraulic sand pattern molding press to make heaters out of castings. We have a small welder, a plasma cutter, a small horizontal band saw, a small sheet metal brake, a small air compressor, and an old bridgeport milling machine. Thus we build what we can with the tools we have given what we have available to us. Maybe someday in the far flung future we will have a 5 million dollar induction furnace to make heaters out of recycled scrap iron, but that day is a long ways out. In the meantime, we have to weld them, thus they wont be winning any beauty pageants anytime soon. What I can tell is is that they are robust, American made heaters built and engineered to do their job with the unfaltering, unyielding, relentless reliability for decades at a time as used to be expected of all American manufactured products in a not so exceptionally bygone era, as was common of American industry. I took my personal job in engineering these heaters very seriously, as the designer I considered it my full obligation and duty to design these heaters to never fail, as lives are on the line, a single failure can lead to death in more than a few ways. I have done everything in my power and full scope of ability to ensure that does not happen, that the owners will stay warm, and that the heater will not clog, jam, or fail, or deteriorate via planned obsolescence (my personal arch nemesis, of which there is no other pattern of modernity I loathe more intensely).

Thank you all for the genuine questions, concerns, and wonderful comments. If there is anything else I can assists with or answer I would be elated to do so.

View attachment 293834

Thanks for your response. And after asking you the question I saw info about adding mass being approved.

But you didn't exactly answer the question are your stoves EPA approved to 2020 standards.

 

[stoveliker]

Thank you; I'm impressed.

Do you have a range of BTU outputs you can achieve?

 

[EatenByLimestone]

Thank you for your replies!

 

[EatenByLimestone]

Thank you; I'm impressed.

Do you have a range of BTU outputs you can achieve?

From the 8 to 20 hour pellet burn times on a 55lb hopper we can figure input of something close to 14k to 42k btu/hr. Take out 20% for the exhaust gas temp, etc and you'll probably be really close.

 

[SpaceBus]

Molecules attaching to oxygen does not make combustion efficient. At the very least you don't understand the chemistry here.

All creosote has actually partially burned. I.e. it partially oxidized. I.e. it "attached to an oxygen molecule". The point is that most constituents of fuel need way more than one oxygen molecule.

Claiming efficiency like this is a huge red flag for me.

We just wrapped up Stoichiometry in my college Chemistry class this week. Thank you for getting to it before me.

 

[rocketheater]

Thanks for your response. And after asking you the question I saw info about adding mass being approved.

But you didn't exactly answer the question are your stoves EPA approved to 2020 standards.

Please do not take this the wrong way. They are approved to and vastly exceed EPA NSPS 2020 standards. My previous statement was very clear on that. The maximum emissions allowed in the 2020 NSPS standards is 2 grams per hour of solid particulate emissions, our heater outputs 0.38 grams per hour. I attached the EPA certified labs test report. I genuinely don't know how much more transparent I can be.

BTU is more a measure of fuel consumption than heat output, but these heaters average between 20k and 35k per hour, depending on variables.

 

[SpaceBus]

Now that I've caught up on the thread I am actually more impressed that it is a UL listed (!) gravity fed pellet stove that can burn limited cordwood. That could have great applications for me as a greenhouse heater, as other options can get even more expensive.

How would this do with dried chipped or shredded wood? I shred tons of conifer saplings and small limbs every year, I would be interested in using it as a fuel if I had the right appliance. Most appliances that can burn chips are far more expensive.

 

[stoveliker]

Please do not take this the wrong way. They are approved to and vastly exceed EPA NSPS 2020 standards. My previous statement was very clear on that. The maximum emissions allowed in the 2020 NSPS standards is 2 grams per hour of solid particulate emissions, our heater outputs 0.38 grams per hour. I attached the EPA certified labs test report. I genuinely don't know how much more transparent I can be.

BTU is more a measure of fuel consumption than heat output, but these heaters average between 20k and 35k per hour, depending on variables.

BTU is a measure of heat energy (and an awkward one at that).
The difference between BTU input (hard, because solid fuels like wood and pellets are variable in BTU/lbs in this respect) and heat BTU output into the room is the stove heating efficiency.

To me (and I gather to the average and environmentally conscious user) the heating efficiency and the emissions is what matters. The latter are related to combustion efficiency, but not the same.

So the combustion efficiency you note (and use for marketing) is not that important, especially when customers compare this to the heating efficiency (the thing they'll notice in the amount of fuel they need to heat their home) which is generally lower, with modern stoves near 80 percent or so. And from the back of the envelope pellet example given above, and the output in your post, I don't think this stove is far off from the current (most efficient) other solid fuel stoves. (I would therefore suggest to be careful using the number as you do, as it can be misleading to the average customer.)

Nonetheless, as an environmentally conscious user, I am impressed by the cleanliness of your stove. That indeed should be explicitly advertised.

The major drawback that I would see is the frequent fuel loading. (Unless pellets are used with the hopper - but I don't like to buy fuel and be dependent on market ups and downs in that - there is a good and useful market for such stoves though.)