Paul Wheaton sits down with Ernie and Erica Wisner to do a turbo podcast about rocket mass heaters. Ernie starts by asking Jocelyn what she feels about having the RMH sitting in the middle of the living room for so long, unable to be used. Jocelyn gives a few downsides to having that but goes on to explain how now that it's running she sees a lot of advantages to it given that it burns cleanly, will reduce moisture in the house and bring the mould issue (that's been happening due to the moisture) under control. Paul weighs in on it too saying that they've been running a propane heater which has been pretty unpleasant compared to the rocket mass heater, which he feels people are really excited about having there.
Ernie follows up with a question for Paul and Jocelyn, asking if the moisture issue has cleared up from using the rocket mass heater which Jocelyn explains that is has.
Ernie and Paul get into how they pulled out all the stops on this rocket mass heater with the aim of making it the prettiest most functional pebble style rocket mass heater possible.
Erica explains some of the designs done on the rocket mass heater and their functions. They discovered in making this stove that it burned at incredibly high temperatures. They discovered this by putting in 4 cones (temperature measuring equipment normally used to measure temperature in ceramic kilns) which were put on the floor of the burn tunnel at the very back (one of the coolest spots of the heater) and two of the cones (meant to withstand 1300 and 1700 degrees fahrenheit) melted down in 2.5 hours!
Since it was burning way to hot, they then had to figure out some methods to cool it down. Ernie explains that they cut the firebox in half, making it so that you could put much less wood being able to be put in, and they lengthened the ducts by 19 feet work to restrict the amount of heat coming through. Even after doing all of that - it melted those cones.
Erica shares a pretty groundbreaking concept that Ernie has been thinking about due to his concerns of all the plastic in the pacific gyre (an enormous island of garbage) – wondering if he can make a portable incinerator that could be put on a boat that could burn plastic cleanly and possibly power the boat. The particular stove at Wheaton labs is hitting temperatures which could make that actually possible.
Ernie shares that the stove at Wheaton labs is different from standard rocket mass heaters because of the high temperatures, which are being reached with even less wood. Ernie is developing a 4” system to be able to heat a large home. Erica goes through the numbers of how amazing it would be to cut your wood use in half, and then in half again, where you'd have wood in your shed to burn for many years.
They move back to talking about the cones, and Paul asked what temperatures Ernie speculates they've hit. Ernie feels it's anywhere from 3000-4000 degrees fahrenheit.
They continue the conversation, between mouthfuls of huckleberry scones, revisiting some of the older rocket mass heater designs and results, and comparing them to the one at Wheaton Labs. Ernie says they are reaching temperatures they have not seen before.
Paul goes back to describe the original design of the poster child RMH, mentioning that he wanted the rocket mass heater to be pretty and go out of the wall. He gives a scenario of when people try to help, with good intentions, but not knowing about the system fully, which ultimately leads to mistakes with the RMH. Paul proposes a design that will be fool proof even if a well intentioned but lacking knowledge type of person tries to build a fire. Paul's hypothesis is that the poster child rocket mass heater design (two pump system) in the main house infuses more oxygen into the rocket mass heater which is resulting in the extreme temperatures. Erica agrees and expands on the theory.
They give a few examples of how having the stove pipe next to the barrel gives the impression to people who don't know how it all works that it is a very hot stove, reducing the chance of accidents and injuries.
They discuss the options for various sizes for different parts of the stoves and how it produces different results.
Paul expresses there is a lot of testing to go – and they discuss the possiblities and business opportunities of shippable core. They go over the benefits of having shippable core since it can reach people who don't have as much time or skill or interest in building and installing rocket stoves themselves.
Ernie and Erica discuss some of their visions for the future of their work. Paul gives some details about the upcoming rocket mass heater DVDs.
They wrap it up by discussing the next year and what will come of the developments of the rocket mass heater, particularly the poster child RMH at Wheaton Labs. Paul gives a breakdown of the numbers of the costs comparison between natural gas/wood stoves etc vs rocket mass heaters, with the results being that rocket mass heaters are much cheaper. Paul also gives a greenhouse gas emissions breakdown since wood heat gives an incredibly low compared to natural gas and electricity etc. Paul makes the point that rocket mass heaters are probably even lower with emissions. This podcast will continue in Part 2.
Essentially, the cones that melted and the way they melted indicate a temperature at that point of around 1500-1700 degrees F. Cones do not have to be held at a temperature for 20 hours; they are designed to melt at their temperature when the last few hundred degrees are approached at a certain rate of rise (for cone 017, 1301F @ 27 degrees per hour, or 1360F @ 108 F/hour, or 1405F @ 270 F/hour).
I think the podcasts with Ernie and Erica are my favorites. This one was excellent. E&E have so much expertise and I really enjoy their interplay and chemistry as they Yin-Yang the information out into the world. Great work everybody and I can't wait for Part 2.
What's the official name for the product under discussion in this podcast? Shippable core? Castable core? It seems like there's been such a breakthrough that it should get a fancy name.
Hi Guys, enjoyed the podcast. I might possibly be interested in looking into producing shippable cores. I have some modest experience in smelting and melting steel and building furnaces and forges. Anyhow, I'm interested to see where you have been going with the idea. I think going with what sounded like a castable foundry refractory was a really good call.
Thanks for the podcast. I'm amazed by the new temps you are reaching, but I have a question. I may not be picking up on all the particulars (podcast, no pictures). Could the temps be so profoundly hotter (high), partly because you are not drawing them down in this instance (pebble-based system, less mass), vs. using a long cob maze (tons of mass), and to what extent can you attribute the difference between 1) the two types of mass, and 2) the super-core for lack of a better name.
I'm a little confused... Another ? When you referred to the shippable core and somebodys burn tube?... are you saying this unit had a pre-made feed-tube, J-tube, and combustion stack all in one castable piece???
Again, thanks for all the info. You guys are amazing!...and Huckleberry scones, WOW.
~ Permaculture is enriching...Farming... is just scratching the surface ~
First of all, great podcast! Thank you for the Nth time for putting out such great, free content. The podcasts w/ Ernie and Erica are always the best! Lots of good, hard info from people who communicate clearly and carefully (i.e. you can tell they consider their words and never make any claims that they can't fully justify).
Second, during the podcast you discuss "tinkerers" vs "plug-and-play" users in regards to marketing shippable cores. I probably count as something slightly different: a "DIY tinkerer." I don't tinker for the shear joy of it, but I tend towards projects where I can do careful, extensive research until I reach the DIY confidence level, then I go do it. Often I find this is better/cheaper than buying an off-the-shelf solution, or else I find that the off-the-shelf solutions are either too generic for my needs or simply not available at all. I am building my whole passive solar, natural-materials house and permaculture homestead this way! I do all the research, I assimilate the knowledge, devise the right synthesis of design features, then figure out how to get it done.
For some years now I have been doing the same with RMHs. I've read the original Ianto Evans book, I have DL'ed and read all of Ernie and Erica's plans, I have bought your original WBS 2.0 DVD set, I've listened to all of the podcasts. Through all of this research, I am slowly assembling the plans for my own, future, DIY RMH build.
Now I come to my point: having established myself as a confident, committed, and accomplished DIY tinkerer, I WOULD STILL GLADLY PAY $500 DELIVERED FOR A WELL-TESTED, RELIABLE, HIGH-PERFORMANCE, PRE-MADE RMH COMBUSTION CORE SHIPPED TO MY DOOR! To whomever it may concern out there considering pre-made shippable cores as a business venture, please take this into consideration.
Third: I missed the kickstarter earlier this year for the new RMH 4-DVD set. Yet I see that they are also still not available for DL at woodburningstoves2.com. Please tell me that they will be marketed to the public via DL soon...? : )
Hey guys! Love all the podcasts; have you guys discussed the carbon capture system, explored here by MrTeslonian? Ever wonder why there are chimney fires? There's carbon fuel in them there pipes! We are literally PISSING GASOLINE OUT OF OUR CHIMNEYS!!!
Wood stove runs a generator "final video" make's gasoline, and propane:
Thanks for all the podcasts! If it weren't for ya I would lose my mind from sheer solitary confinement! :/
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Switching from electric heat to a rocket mass heater reduces your carbon footprint as much as parking 7 cars