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Post by keithturtle on Jan 7, 2016 22:34:17 GMT -8
Must be cheaper with trade prices and in bulk. But still mighty dear. Gasp, choke... I don't mind working overtime but that will leave me with clay on my hands for now Turtle
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Post by twd000 on Oct 2, 2016 18:08:56 GMT -8
I wasn't able to find any results for the rocket heater in the decathlon competition. One article made it sound like it did not make it to the final round?
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Post by ericaus on Oct 8, 2016 0:29:39 GMT -8
I'd be interested in hearing any follow up also. I would have thought that the batch box bell would have been miles in front of the other contenders for efficiency. Maybe Peter or Matt can enlighten us here.
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Post by matthewwalker on Oct 8, 2016 8:27:04 GMT -8
The end result is a rocket can not be tested appropriately using current EPA accepted protocols.
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Post by patamos on Oct 8, 2016 10:32:07 GMT -8
The testing devices measure emissions per hour. This is assuming everyone is trying to achieve a long slow burn, ala metal box stoves. The rocket burns all of its fuel load in one hour but effectively stores it for gradual use. The low exhaust temps (after harvesting) and low grade heat from a 'huggable' conductive heat source offers the greatest level of personal comfort with the least amount of wood burned. Some mass heater advocates are suggesting the test criteria should be changed to 'emissions per volume (kilo/pound) of wood burned. This is a step in the right direction, but still does not indicate the harvesting and distribution effectiveness of these heaters.
As good as metal box stoves are getting, mass heaters are in a whole different paradigm. Once you fall asleep on one and wake up with a river of druel out the side of your mouth… there is no going back.
At this point, the only way to verify many of the ways in which masonry and rocket mass heaters are more efficient is via word of mouth (amidst the din of big oil advertising...)
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Post by ericaus on Oct 8, 2016 12:39:44 GMT -8
Thanks Matt and Pat. I didn't realize that was the case. That's really quite poor. I'm not sure that is the case with the local Australian testing standards. I've got a copy of them somewhere so I'll check on the methods.
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Post by matthewwalker on Oct 8, 2016 14:25:10 GMT -8
No problem. I agree with Pat in that the quality of life with a masonry heater fits my preferences better than a box stove. I disagree with most RMH proponents' in that I believe the modern box stoves are every bit as efficient as our best efforts, and likely cleaner. I don't know that for sure, and I don't believe there is a large gap, but I don't think we are doing much better by the numbers. That's my opinion, from standing right next to them going full tilt for a week, and watching the same testing gear going from heater to heater.
The best way to sort it all out for yourself is read your test protocol and try to do it. You'll learn a ton, even if you don't have any measurement tools. Just sorting out the fueling and warm up and all that is an education in what the challenges are to getting a legal heater in your area.
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Post by twd000 on Oct 10, 2016 7:01:15 GMT -8
No problem. I agree with Pat in that the quality of life with a masonry heater fits my preferences better than a box stove. I disagree with most RMH proponents' in that I believe the modern box stoves are every bit as efficient as our best efforts, and likely cleaner. I don't know that for sure, and I don't believe there is a large gap, but I don't think we are doing much better by the numbers. That's my opinion, from standing right next to them going full tilt for a week, and watching the same testing gear going from heater to heater. The best way to sort it all out for yourself is read your test protocol and try to do it. You'll learn a ton, even if you don't have any measurement tools. Just sorting out the fueling and warm up and all that is an education in what the challenges are to getting a legal heater in your area. Thanks Matt I've been trying to wrap my head around this question of efficiency. I see RMH proponents claiming 8-10x reduction in wood consumption compared to a box stove. But I suspect they are comparing to a pre-EPA stoves with no secondary burn capability. In contrast to a modern catalytic stove from Blaze King or Woodstock Soapstone, etc. An 8-10x reduction would certainly be of great interest to those of us cutting splitting and stacking 4 cords of firewood per year, but it seems too good to be true. I agree that the quality of life and personal preferences can only be decided by each person, but every time I see a RMH proponent making fantastical efficiency claims, I feel obligated to question them
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Post by matthewwalker on Oct 10, 2016 13:41:18 GMT -8
Yeah, those two you mentioned, and the Lopi that was at the Deathlon, are tough to beat. I think they still are better than our best for everyday use, in terms of efficiency, emissions, and ease of use. They aren't cheap though, and you aren't going to build one yourself. They also are pretty much small masonry heaters at this point, the WS stoves are coming in at over 700lbs now, with a lot of that soapstone. Rather than bad mouth box stoves, I think it is inspiring, and gives us something to aim for.
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Post by twd000 on Oct 10, 2016 14:48:40 GMT -8
Yeah, those two you mentioned, and the Lopi that was at the Deathlon, are tough to beat. I think they still are better than our best for everyday use, in terms of efficiency, emissions, and ease of use. They aren't cheap though, and you aren't going to build one yourself. They also are pretty much small masonry heaters at this point, the WS stoves are coming in at over 700lbs now, with a lot of that soapstone. Rather than bad mouth box stoves, I think it is inspiring, and gives us something to aim for. Agree on all counts. And I find it fascinating that two completely opposite approaches can be taken to liberate the most BTUs from a stick of wood. The box stoves smolder a load of wood for half a day or more, and let the catalyst "eat" the smoke. The rocket heater burns that same load of wood in and hour, relying on intense secondary burn to extract as many BTUs out of the wood gas as possible. Both get the job done in their own way
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Post by patamos on Oct 10, 2016 20:48:31 GMT -8
Both 'burn-on-demand' and decoupled-fast -burn' becoming more refined.
Matt's halfrisers and Trev's vortex in low-primary air supply achieving slow gassifier abilities.
The paradigms are merging.
I wonder how well reburners can mimic a gas/electric cooking element?
And for comfort, i don't think anything will surpass curling up on a bench sending far infrared heat into our tissues. Deep cleanse and relaxation… not to be underestimated...
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Post by satamax on Oct 11, 2016 0:48:55 GMT -8
Yeah, those two you mentioned, and the Lopi that was at the Deathlon, are tough to beat. I think they still are better than our best for everyday use, in terms of efficiency, emissions, and ease of use. They aren't cheap though, and you aren't going to build one yourself. They also are pretty much small masonry heaters at this point, the WS stoves are coming in at over 700lbs now, with a lot of that soapstone. Rather than bad mouth box stoves, I think it is inspiring, and gives us something to aim for. Well, just a daft question, what is the exhaust temperature of the stoves you mention, at full tilt?
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Post by matthewwalker on Oct 11, 2016 6:35:26 GMT -8
From what I observed they hold pretty steady in the high 200°F range.
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Post by patamos on Oct 11, 2016 7:44:21 GMT -8
i'm curious to know the optimized average fire temps and exhaust temps under real-world firing conditions.
eg, if a stove is aiming for 500c in its reburn chamber and 80c exhaust but a rocket is aiming for 1000c in its core and less than 80c exhaust... there is a 20% or so advantage in harvesting
BUt if their reburn/catalytic converter is cranking up over 700c or 800c, then a mass heaters only real advantages are conductive heat source and minimization of convection loops.
box stoves and pellet stoves can add a electro-mechanical fan, but that brings in a whole nother can of worms - not to mention annoying white noise...
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Post by twd000 on Oct 12, 2016 9:50:17 GMT -8
i'm curious to know the optimized average fire temps and exhaust temps under real-world firing conditions. eg, if a stove is aiming for 500c in its reburn chamber and 80c exhaust but a rocket is aiming for 1000c in its core and less than 80c exhaust... there is a 20% or so advantage in harvesting BUt if their reburn/catalytic converter is cranking up over 700c or 800c, then a mass heaters only real advantages are conductive heat source and minimization of convection loops. box stoves and pellet stoves can add a electro-mechanical fan, but that brings in a whole nother can of worms - not to mention annoying white noise... I don't think the internal burn chamber temperature matters from an efficiency standpoint (it certainly matters from a materials science standpoint) A simplistic view of efficiency would only account for the total volume of combustion/makeup air, and the final exhaust temperature of that air. Any woodburning device uses room air for combustion and finally puts it out the chimney. A more efficient wood burning devices uses fewer cubic feet of makeup air, and exhausts it at a lower temperature, compared to a lower efficiency device. Optimizing the internal burn temperature is only a means to achieving that end. A catalytic stove optimizes its efficiency with a low-temp primary burn plus a high-temp secondary burn. A rocket optimizes its efficiency with a high temp primary burn plus turbulence to induce high temp secondary burn.
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