[quote=Peter van den Berg][quote=Miguel Moreno]Does having a bigger stove, like a 10" mean I have to burn bigger, more frequent fires to get it to work appropriately, even if I don't want want that much heat in the space? [/quote]
The thing with a batchrocket is this: it can be run with half a load and burn very clean all the same. Even the duration of the burn is about the same as compared to a full load. I am used to long shoulder seasons so I run my heater once in two days or just[/quote]
[quote=Miguel Moreno]Does having a bigger stove, like a 10" mean I have to burn bigger, more frequent fires to get it to work appropriately, even if I don't want want that much heat in the space? [/quote]
The thing with a batchrocket is this: it can be run with half a load and burn very clean all the same. Even the duration of the burn is about the same as compared to a full load. I am used to long shoulder seasons so I run my heater once in two days or just once just to get the chill
[quote=Glenn Herbert]A bigger system would mean bigger fires, but not more frequently. As you are in a seriously cold climate with fairly steady heating needs, making the walls of a bell thicker would make the heating more stable and hold heat longer, at the cost of longer lag time before heat makes its way through the walls to your space. If you can fire up the Walker stove for some quicker heat if you really need it, I think I would go with the big fat batch box and expect to usually do fewer[/quote]
A bigger system would mean bigger fires, but not more frequently. As you are in a seriously cold climate with fairly steady heating needs, making the walls of a bell thicker would make the heating more stable and hold heat longer, at the cost of longer lag time before heat makes its way through the walls to your space. If you can fire up the Walker stove for some quicker heat if you really need it, I think I would go with the big fat batch box and expect to usually do fewer fires per day.
[quote=thomas rubino]Hey Miguel;
Having a Walker cook stove makes a difference.
I suggest you build an 8" batch.
Foremost is your chimney 8" or 200mm are widespread and readily available sizes, ten inches is not.
An 8" batch is plenty of stove to share space with a Walker.
Plan on two burns to heat up the whole bell system.
[/quote]
Thanks for the insight, Thomas!
I do have access to 10" chimney and all the components for the chimney system, although the cost is certainly
Hey Miguel;
Having a Walker cook stove makes a difference.
I suggest you build an 8" batch.
Foremost is your chimney 8" or 200mm are widespread and readily available sizes, ten inches is not.
An 8" batch is plenty of stove to share space with a Walker.
Plan on two burns to heat up the whole bell system.
actually made that effort in the 1970s but didn't get it adopted because everyone had already decided that steam was going away so why bother.
We're fully burning the fuel same as a RMH, once it's up
energy generation, including rocket mass heaters. We could just watch one of the videos on permies, but if there's someone who lives nearby that has experience with building and/or using a RMH, we would
in and experience house the house feels. I plan to have 2 windows in the attic area. I have no intention of using membranes or moisture barriers (expect the tar paper).
of energy from the sun during winter, which if electricity could be converted from a wood stove or RMH during those same winter months…maybe, just maybe, right?
the generator. Either as longer duration, to meet your electric demands, or possibly hotter to supply heat for both?
I think there's some real potential for a RMH barrel-top Stirling engine generator
I want to wrap my copper coils tightly around the exterior of the drum, and thermosyphon to a hot water tank above the ceiling. I live in a warm climate and don't need much space heating. Any issues? Of course I'll use an expansion tank and a temperature / pressure relief valve.
I actually built mine to take all the heat out of the exhaust, hence the location of the coils. It does a pretty good job of removing the heat, the exhaust is about as warm as a dryer vent. I've got 110 feet of coil, and am probably going to put an additional 50 in there to scavenge even more. In theory, I'll have enough coil in there if the exhaust temperature matches the water inlet temperature. Because I live in a doublewide, radiant and mass heat were not options for me, especially since I
"above the heat riser" - is yours a tight coil of copper pipe (forming almost a solid cylinder) stacked above the brick/insulated metal riser? Then does this rise up until the 1.5"-2" gap under the top of the drum? I think this would cool the gas too soon. It should not cool until is has hit the lid and spread so it can fall down the drum, instead of wanting to fall down the riser.
I'm not using the coil to take away heat from combusting wood gases, and the flame does not contact the coil.
On my rocket stove heater (a fully hydronic system), I placed my water coils above the heat riser, so as to prevent taking away any heat from the combustion of the wood and wood gases. I also wanted to be sure that the copper coils never came in contact with direct flame as they are quite expensive to replace. The flame would probably erode away at the copper pipe over time, requiring it to be replaced. I'm not sure if it increases the rocket effect or not to be quite honest with you. It does
Hello, I was wondering if adding a hot water coil inside of the drum would actually increase the rocket effect?
It is my understanding that the cooling of gases as they exit the riser contributes to the movement of the gases. Hot buoyant gases rising in the riser, cool gases falling in the drum. So, adding a coil for heating water inside the drum should increase the cooling effect. The water should be actively pumped to the tank, and the tank needs a boiler grade pressure relief valve (thanks
Stephen, this plot is very well thought-out. Were you going to have a rmh anywhere ? Or a fire pit /biochar area? These may be available near the Abbey, etc. and may be unnecessary duplication
don't know what your winters are like and maybe you don't mind cold and draughty anyway cause you're sitting on your rmh bench. If you're going with sawdust, might be a good idea to figure out how
in many of RMH designs, but I've never seen them used on the riser, which may very well add a bit more of the Three T's we look for, (Time, Temperature, and Turbulence) at the very last opportunity
Since I live in a city and I'm subject building codes, plus I'm still paying on my mortgage, and there's the insurance issue,I just mess around with rocket stoves.
If I could build freely in my house, I would have built a by the numbers batch box heater by now.
The ability to be free from paying for heat would be worth it.
hard to read when bouncing between options. To me a RMH really seems like a great option because of my lifestyle, being able to have a warm mass at the center of the house, and have that heat be retained
If you're new to rmh, or not, this is a great movie to check out. I mean, come on. Free Heat!
But seriously, this is a great video to check out with lots of great information.
[quote=thomas rubino]Brand new 2500F Heavy firebrick is just over $2 each.
5" sections of HVAC pipe are under $20.
Crappy sand is free, high-quality sand is less than $20 per #100
Fireclay is $10 a #50 sack
Brand new plain solid clay bricks are .60
[/quote]
Where the heck are you sourcing because I want those deals!
I was quoted $5.81 per firebrick, picked up in person at a major manufacturer.
I paid $75 for a 50 lb bag of fireclay in 2020 and now the same bag is running
Brand new 2500F Heavy firebrick is just over $2 each.
5" sections of HVAC pipe are under $20.
Crappy sand is free, high-quality sand is less than $20 per #100
Fireclay is $10 a #50 sack
Brand new plain solid clay bricks are .60
You can spend as little or as much as you would like, but you may have to travel to find those supplies at good prices.
This thread touches on how far rocket stoves have come from their affordable roots.
They still trump other diy stoves but some of the improvements in performance have come at a cost in materials.
Even firebrick has been reported to fail and need replacement in certain parts if some rockets.
I think the original j tubes used old red brick and replaced them as they failed.
A core cast from high temperature refractory might be competitive in price to the cost of a firebrick core, but it
You do have to use good quality refractory materials for the fire box and the riser, elsewhere you can use clay red brick, you could look for second hand fire bricks.
The half-barrel stratification chamber is a great way to go. Not only do you lose the expense of the length of tubing running through the mass, but it's a lot less restrictive because it's not subject to the friction of the smaller diameter pipe. Peter's documentation of his build is legendary and this makes it easy to follow.
After reading about RMH my first thought is to build the basic J-tube design, use firebrick for the heat riser, combustion chamber, etc. I also saw the twisting stovepipe as a great way to run 20ft
still working on all of the above so I haven’t planned much beyond that except that I’ll be installing our bench style RMH soon because winter heating around here is quite pricey. Ideally we’ll keep
[quote=Monica Truong]There is work on a RMH that can produce electricity!! The people at Wheaton Labs are tinkering with that concept this July!! At the Permaculture Technology Jamboree. See https[/quote]
There is work on a RMH that can produce electricity!! The people at Wheaton Labs are tinkering with that concept this July!! At the Permaculture Technology Jamboree. See https://permies.com/s
I am considering purchasing land in Alaska near the Kenai peninsula someday, as I abhor the heat and humidity at this point. It’s early April and I can’t go outside for 10 seconds without beading sweat.
I desperately want to put to use many of these permies principles afforded to individuals that own wooded land and have access to felling trees.
I love being cold, I spend 10 minutes in the Wawa beer freezer when I go there. It’s much easier to bundle up and start a fire than take your
Hey Dick I should have popped in here earlier but if you ever need any refractory materials in AK I highly recommend checking out Distribution International in Anchorage. That's where I sourced my materials for a charcoal forge I built a few years ago. They had everything I needed according to my applications, knowledgeable guys they were. I recently inquired about heavy duty fire brick as well as ceramic fiberboard and they had both in stock, but it has been about six months since my last
We are trying to figure out some sort of fiber material to use, that is a good idea I forgot how important the fiber can be. And thank you for letting me know about the cracks that makes me feel a lot better about them I thought we were doing something completely wrong! We’ve put so much work into it I would hate to see it crack to pieces. It has been lots of fun playing with the mud though. Thanks for the help!
Looking good!
Glad to hear your enjoying the beginning of a long season of burning... may it not get old or seem like a chore during a long Alaskan winter.
Have you experimented using any form of fibre in your cob mix? Even if it’s something as fine as cattail fluff (normally reserved for a finish plaster) it may be all you need to keep the cracking to a minimum.
Some places that experience higher temps, joints or that are adjoining dissimilar materials may always want to crack but the
So I may have been a bit dramatic with the weather timeline. I think we still have a few weeks until we hit freezing temperatures. It has been rainy with 50-55 degrees F.
Eloise, I wish I would have checked back earlier we could not find ceramic blanket anywhere. We already have our heater built and we are currently firing it and filling the mass. We did find plenty of fire brick thick and thin at a masonry place in Wasilla.
We did go back and re-do our base layer with a sand perlite
You may have already chosen your course, but I thought I'd share this in case its helpful. Another permies user mentioned difficulty sourcing materials in Alaska on a thread I had started a while back. https://permies.com/t/173455/Rocket-Masonry-Cook-Stove-Home
He mentioned Distribution International in Anchorage, and said they have all sorts of refractory materials in stock (that was 6 months ago). Maybe give them a call and see if they have what you need? Also look for a
Hi dick. I've never used rock wool so not sure how easy it is to use .I purchased most of my ceramic insulation on Amazon. Usually kicked off at my door within four days. Might be different in Alaska. I really do urge you to look into it. Easy to work with and it works. Hate to see bad things happen to a beautiful build. Thanks
I have contacted Thomas Rubino via e-mail to see if he can ship to Alaska and how long/expensive it would be to get here. Home Depot does have mineral wool it looks like but no ceramic insulation unfortunately I have called all locations of Lowes as well. Winter will be here shortly so we do not have too much time to wait for shipping etc otherwise I would just order it. I’d say we have about 3 weeks maybe 4 to get this built before temperatures start to dip into the 30*F. We have no heat
[quote=Dick Winters]Unfortunately we can not find anyone who has high temp ceramic blanket that’s why we were hoping to use the clay/perlite mix around the whole combustion unit.
[/quote]
You're in luck, it is readily available by mail order from Thomas Rubino: https://dragontechrmh.com/morgan-superwool-plus-non-ceramic-fiber-blanket
Shouldn't require more than about $30 worth of morgan-superwool to insulate the combustion unit. While you're ordering, might get a little extra to use
there and they say how hot an rmh or in my case rmhf they burn hot at least mine does. Unless you have seen one in real life burning and operating you can't feel the heat from a video. I would really look hard
Okay I understand what you guys are saying thank you. Unfortunately we can not find anyone who has high temp ceramic blanket that’s why we were hoping to use the clay/perlite mix around the whole combustion unit.
As for the foundation we plan to put 2” of sand on top of the cement board and then add a second base layer of firebricks underneath the core. It is more costly but I’d rather overbuild it once than have to build it twice. Hopefully this is a much safer and better way to go. What
Hi Dick, these threads can get a bit confusing when you get mutable folk trying to help and as Byron points out there are different approaches as to how these stoves can be put together!
Do you have access to high temperature insulation like ceramic fibre products?
It is possible to use clay, straw and pebbles and other organic materials but more high tech materials will make your build far more efficient and easier to build but of course will cost considerably more money to
[quote=Dick Winters]...does it make a huge difference if the dimensions are a half inch off here or there? I assume the CSA, precise dimensions, are to ensure the “thermo siphon” works and the unit drafts correctly. [/quote]
The vertical wood feed, then the horizontal burn tunnel, should be as close as possible to the same dimensions, for best draft performance. If one must be slightly less CSA than the other, make the one with slightly less CSA be the vertical wood feed.
Thank you for telling me this now before we start our second attempt. We would have been in big trouble. I will look at the book today and see what you mean Byron. We were going to insulate the whole J tube with clay perlite mixture. Is this okay?
Also (NOT trying to be a smartass) does it make a huge difference if the dimensions are a half inch off here or there? I assume the CSA, precise dimensions, are to ensure the “thermo siphon” works and the unit drafts correctly. Is
If you are building a 7.5 inch system then the whole inside needs needs to remain exactly the same i.e. 7.5” x 7.5” from the top of the loading port to the exit at the top of the riser.
It looks like you’re using split fire bricks, they should be fine if they’re good quality just bear in mind that the exterior of the brick, after one hour of burning, will be 500°C or more!
As Thomas points out you need to offer some form of insulation between the base of the unit on the floor.
You can
After consideration with my wife we will be taking it all down and buying a wood stove. No just kidding we will be taking it down and insulating the floor better and then we will build it again. I hate to take it down after just getting it done but it is much easier to fix it now than later when it is totally finished. Thank you for the tip!
Perlite mixed with clay would be a nice base for it correct? On top of the cement board?
Hi Dick;
I would stop your build now and consider raising that whole core and cement board on clay bricks laid flat.
Sitting tight to the floor, that core will burn thru the cement board after? one season maybe two? After that, it's your flooring itself that chars.
If you raise your whole core build 2.5" or so, then your flooring is safe.
If left as is, you will have trouble down the line.
After the core the temps are low enough that you could sit cement board on your flooring if needed.
That is an excellent question I was so concerned with getting the width correct at 7.5 I don’t think I ever checked the height. The riser is 46.5 (should be 48) and the overall interiorlength of tunnel is 24 and both openings are at 7.5 or very close. But I forgot to check the height of the feeder which should be 16 I think I’ll have to look at the book for reference. Other than that is there anything else that looks odd? We used the clay slip to seal everything up. As always I appreciate all
Hi Dick, neat start on the combustion unit. I'm not sure if it's the photo angle etc. but it looks like the burn tunnel may not be tall enough inside. From the floor of the burn tunnel to its ceiling, is it the same measurement as the span / diameter of the wood feed opening?
I am in Wasilla. That’s awesome you are in AK as well I love talkeetna! We have never built an RMH before but are very excited to give it a shot. We hope to start building this weekend
Hello to all-
Dick and Eloise, what parts of Alaska are you each in? I am out in Talkeetna. We are planning to build our place with a RMH as well. Have taken a sort of class here. Was very hard
Quick update for everyone! I have read all your replies but haven’t had a ton of time to be on my phone replying, we have been extremely busy trying to get our house insulated, wired, etc. thank you guys for responding and giving me insight/advice I appreciate ALL the help and wisdom I can possibly get so thank you!!
We have decided to go with an 8” J box style with 16’ of piping if we can fit that much in our tiny house. 14x24 feet. We are currently debating whether to go through the roof
Just came across this thread. I too just moved to Alaska and hope to build an RMH (probably won't be for about a year as we need to get a place to build it first). Wondering if you have made any
You will not find much info about batches in the RMH book.
All the current info can be found here at Permies.
At Peter Bergs site http://batchrocket.eu/en/
Or at my site https
will definitely check that out. We used 2x6 studs for the frame to achieve better insulation. I am still waiting on the book to come in and once I read it I will have a better idea of what size and style RMH we
I have ordered the book on RMH and am waiting on its arrival to figure out the correct “model” to use. I’m sure I will have questions once I am set to start. We will be in a 14x24 house with 2x6
heater with a few particular design characteristics. Alaska is indeed the perfect environment for an RMH, with its continuous heat reservoir and ability to burn wood, even softwood, efficiently and safely
You guys I’m new to Permies and also new to Alaska. Also I have never built a RMH. I am very excited to see how it does up here. I have asked around and people seem to like the masonry heaters
- Tangle foot fence
- Junk-pole fence
- Rockjacks
- Haybox cooker
- No more external air intake for rmh - Incandescent and led lighting at the Labs
- Workstation dock
- Cooper
- Tangle foot fence
- Junk-pole fence
- Rockjacks
- Haybox cooker
- No more external air intake for rmh - Incandescent and led lighting at the Labs
- Workstation dock
- Cooper
with another couple, for 8-9 mths of the year (RMH/Composting toilet/Rocket Oven etc etc) and only have 12V solar for power - so make sure which ever system you go with has a 12v charger to charge
If only a Gen Z permie influencer would come along and make RMHs a TikTok aesthetic. (Cue video short of young woman in neutral natural fiber clothing feeding twigs into a rmh in her scandi
Small scale, local energy production is where it's at, IMO. For me, a rocket mass heater is the solution. If everyone who needed to heat their homes used a RMH, the pollution caused by our
I'm not sure about that, but people are planning on making a RMH forge this year at the PTJ. See thread here. Get in on the convo here at https://permies.com/t/215728/PTJ-Rocket-Forge-Design-Thread
the metal. I imagine there would have to be a manifold to redirect the hot gasses into a mass and without a standard rmh barrel assembly, it may not draw properly, if you are trying to heat a bench
Are there plans to make this RMH produce electricity while it forging a knife? That would be crazy cool! The main PTJ thread has a "RMH that generates electricity" as a possible project....
I will say though that being a boiler guy, mine is not a rocket mass heater but a conventional wood boiler. Others might jump on here who have done RMH with oil drips though.
I have built a RMH and multiple outdoor rocket cooking devices in Delaware County NY, somewhat near Eastern PA. I'd love to build one for someone or help out. Email: gell.sophie@gmail.com
Is there anyone in or near Pennsylvania who is skilled in building an RMH? My husband and I will be purchasing a new home in the next year or so, and we'd love to have an RMH, but absolutely don't
[quote=David peckham]Hi, I built a 6" rmh in southwest Idaho, and it works just like its supposed to. I'm happy to help others nearby, and into Eastern Oregon.
Dave Peckham[/quote]
Hello
I am in Regina, Treaty 4 lands, Saskatchewan, Canada
I have built 6-inch, 8-inch RMH and i did a 8-inch batch box.
I have been hired to put on a 2 day workshop which we built 8-inch RMH
I've built a functioning 6" underfloor RMH in my greenhouse.
I'm located near Whitehorse, Yukon, Canada.
I would be happy to give assistance to others.
Hi, I built a 6" rmh in southwest Idaho, and it works just like its supposed to. I'm happy to help others nearby, and into Eastern Oregon.
Dave Peckham
A RMH making electricity would be very cool. A RMH heating water would be a pain in my butt that I wouldn't even consider for indoor/house plumbing. How to keep it from
. But at any rate, the talk of heating hot water made me think about RMH (I'm a little obsessed with them at the moment) and what if we could use hot water to create electricity?! A RMH could be modified
https://permies.com/s/ptj-bogo-sale Seems to me that the RMH can replace most of our conventional gadgets for heating, cooking, baking and now the possibility of powering electric gadgets
on the roof rack of a Subi.
On trips to Pacific Steel, I can get much larger pieces of metal and easily bring them home.
Hauling home piles of brick for RMH Construction.
Sometimes it may even
might read it quickly like I did and be confused. It seems like the accident was related to improper ash removal which could happen with any wood burning device. Yours just happened to be a RMH. If you
like I did and be confused. It seems like the accident was related to improper ash removal which could happen with any wood burning device. Yours just happened to be a RMH. If you read the title quickly
[quote=Glenn Herbert]One thing about a well operating RMH is that except in the coldest weather, it does not need to be run continuously, and will burn all coals to mineral ash. These facts[/quote]
One thing about a well operating RMH is that except in the coldest weather, it does not need to be run continuously, and will burn all coals to mineral ash. These facts will allow you to only clean
that caused the fire. We operated the RMH for years with no problems but it only took 1 mistake to ruin it all.
Amos, thanks for reaching out. I confess I am a little sick looking at the damage
. The hot side of many commercially available hobby-grade TEGs would handle placement on the top of a RMH barrel as long as you paid attention to the heat shielding of the wires.
TEG relies on a heat gradient, not just being generally hot. You need to have hot side - in contact with a wood stove, for example, and a cold side - careful cooling with fans or something similar. I suspect that the heat from being in the hottest part of a rocket stove (around the barrel) would damage the TEG components. I don't think this is something that could be easily homemade. An off the shelf version is probably the best bet. They are inherently low energy conversion efficiency. You
electricity from a Rocket Mass Heater. If we were running a RMH or other rockety device on a regular basis, it would be great to use a little of that energy to be trickle charging some kind of truck or deep
Since I have an electric kiln at home, I bisque fired the dried perlite-clay riser with its stovepipe outer form and cardboard inner form, and got the whole thing decently sturdy for installation. Just burning out the liner would work, though it would not do anything to strengthen most of the material.
Thanks! Yes, it's Cone 10 and I also thought that a quite liquid consistency would be good for the inner coating. Maybe even as liquid that it would be possible to lay the riser on the side (after the liner is burned out or removed in another way), splash a line of the mixture and cast it on the surface by rolling it. The dried perlite clay will soak a lot of water I think so it shouldn't remain that liquid for long and will possibly build a more stable connection to the perlite clay as you
When people talk about fireclay and perlite, they generally mean powdered fireclay which is as fine as dust. Stoneware clay slip (especially finer material with little grog) should work well with perlite. I would make sure it is cone 10 stoneware (typical gas firing grade) rather than cone 6 (typical electric firing grade).
From my experience, removing the internal form from a perlite-clay riser would disturb and crumble the inner surface. Burning out the liner would work much better, and
Is there a reason why the perlite riser shouldn't have a thin layer of fireclay mortar on the inside to prevent it better from crumbling in this area and for a smoother and more long lasting shape? The mortar I would use is rated for 2370°F. On the outside I will use a metal cylinder so crumbling on the outside won't be a problem. Someone got experience with that? From my understanding that layer would'nt absorb much heat if it has a thickness oft just 2mm or something like that?
The chimney will rise outside above roof level after leaving through the wall and end at a height of around 11,5 ft. See the attached second drawing of the chimney planning.
I purchased 6" stove pipe and now got the question where to plan the connection of the pipe for the bypass to the radiant chamber. Glenn wrote "at the side of the Bell". But which height? I suppose that closer to the top oft the radiant chamber respectively the same height where the riser ends means better draft in cold starting conditions, right? But since I want the upper barrell to be removable a connection there would make it necessary to remove this connection for
I would say crushed gravel, which is angular and will lock together, is more stable than round pebbles. Of course, if the whole thing is contained so that it can't ooze out to the sides or sink into the ground, any stone material would work fine for this relatively minor load. I think all you really need for damp isolation would be one layer of fairly uniformly sized material, and a sheet of cement board or something equally rigid and noncombustible to keep perlite from sifting down between
I have no building experience on this yet, but having looked into such things some I've worked out the need to focus on material specifics. You will have better luck dry stacking rocks than stones. When paving with bricks you want to use mason sand, not beach (playground?) sand. Sharp things end up more stable than round ones. If I'm reading the situation right you need to use gravel, not pebbles, but I'm not sure how nuanced the distinctions get...
that it can't move it should work? I once built a rubble trench as foundation of a strawbale-building, so I have some experience but the difference is that in case of the rmh it would just be a thin layer. I'm
[quote=Jonas Fritzsche]1. Should there be a layer of compacted rubble between the concrete foundation slab and the perlite-clay layer under the RMH? Ernie and Erica write in the builders guide[/quote]
the RMH? Ernie and Erica write in the builders guide that they almost always start with such a layer to protect the cob from damp. The cabin is located in a forest in humid climate. Or does the perlite
Now I actually found a bagged product from a german manufacturer. Its a fine clay mortar for oven building (grain size 0-1mm but mostly <0,3mm) that can be used for a layer thickness between 2-8mm
"Fireclay" does not mean that it has been fired or contains fired components. It is a high-heat-resistant type of clay which typically will not expand significantly when heated (thus not putting stress on neighboring materials). It will be high in alumina (around 30%). Firebricks are made from generally pure fireclay.
If you cannot get "fireclay" from a supplier, pottery clay like porcelain or stoneware should be fine for your purposes. Pottery clays often have grog (particles of ground-up
1. Should there be a layer of compacted rubble between the concrete foundation slab and the perlite-clay layer under the RMH? Ernie and Erica write in the builders guide
[quote=Glenn Herbert]First, Jonas is proposing about 1 1/2 barrels in height, so cobbing some of that still leaves a lot of radiator surface. Bells typically are mostly if not all masonry, aside from the shop versions designed for fast heating. The drastically lower drag from switching from ducts to bell means less boost is needed.
Stratification/bell systems do not have any significant horizontal ducting, and vice versa, so I am not sure what combination examples you are referring[/quote]
[quote=Scott Weinberg][quote=Jonas Fritzsche]Hello people on permies,
Here is a short description of the space and my plans for getting an opinion on that question:
The floor of the house is concrete, a layer of polystyrene and a wooden floor above that. The walls are build with aerated concrete covered with lime plaster inside and outside (no additional insulation). The room inside measures 118 squarefoot (almost square shaped) with a ceiling height of 90". I use it mainly as sleeping[/quote][/quote]
I've had a bit of experience with the "juice box" systems at basecamp, in construction and operation. I've witnessed problems there, but no experience with the lowered exhaust pipe in a more open "bell" type chamber.
First, Jonas is proposing about 1 1/2 barrels in height, so cobbing some of that still leaves a lot of radiator surface. Bells typically are mostly if not all masonry, aside from the shop versions designed for fast heating. The drastically lower drag from switching from ducts to bell means less boost is needed.
Stratification/bell systems do not have any significant horizontal ducting, and vice versa, so I am not sure what combination examples you are referring to.
I'll start by saying that using an open bell design for the bench and the extra high radiant chamber (or first bell as Jonas labels it) adds a couple of variables outside my grasp of RMH conventions
Here is a short description of the space and my plans for getting an opinion on that question:
The floor of the house is concrete, a layer of polystyrene and a wooden floor above that. The walls are build with aerated concrete covered with lime plaster inside and outside (no additional insulation). The room inside measures 118 squarefoot (almost square shaped) with a ceiling height of 90". I use it mainly as sleeping and living room.[/quote]
The firebrick slab at the back of the feed tube sounds good to me, as does the partially cob-encased barrel. You would want that cob to be placed to allow the barrel(s) to be removed for maintenance. It needs to only go halfway around touching the barrel, though it can be as thick as you want near the barrel.
After reading quite something about bell theory and purchasing and reading in Ericas and Ernies Builder's Guide I altered the design a little bit and some new questions came up.
first the design changes: To get an ISA closer to the 5,3 m² that would be ideal for an 6" system according to batchrocket.eu I decided to change to 55 Gallon Barrels as bells (both: above the riser and in the bench) and because of the lack of horizontal space building a relatively high (170cm / 67")
Thanks again for your advices Glenn! I will alter the dimensions of the cross sections as suggested. I took the recomendation of using 5" x 6" as cross section from the book from Ianto and Leslie and like it was said before it seems a little outdated. So I think I will dive into some more recent theory and instructions about the build and post questions here if I keep having open questions.
I still got some time because I'm planning on having it finished when the next cold season starts
Thanks for the detailed drawing. It allows for equally detailed advice. In general, I think you are on a good track.
The first detail I will mention is that it would be better if the feed and burn tunnel are both 15cm square rather than 15 x 12. It has long been advised by innovators that a burn tunnel should be taller than wide if it is not square. Ash will accumulate in use, and even a couple of cm will make a big difference in 5 cm of space. A modest bed of ash in the floor will help
Attached you find a sketch that I made today. I made it mostly to clarify dimensions and the rough shape of the hole RMH and for seeking the right position for the combustion chamber in it. So some
I think 15":20":45" would work, but don't see a benefit to making the feed deeper than the firewood. 13.3":20":40" would most likely work well.
I have found with my 8" J-tube and bell that my temporary 6" stovepipe chimney (about 18' from firebox floor to top) draws fine. You may be able to use your existing 4.5" roof penetration, keeping everything before that to 6". Be prepared to seal that and go out the wall as you indicated if necessary.
If a common firewood length in your area is 35cm, your suggested dimensions sound good to me. You don't have to orient the burn tunnel at right angles to the bench; that seems too close for comfort to the bed for my taste. You could point the burn tunnel about 45 degrees, directly away from the back corner, and have the feed almost within the outline of the bench.
Bell theory, design and construction is covered well at batchrocket.eu
As you are already planning on a 6" system, I would advise making the J-tube dimensions larger so you can use longer firewood. Ideally you would make the feed tube the same depth as your standard firewood, but that might be a stretch. If your firewood is similar to the US standard of 16" long, proportions of 1:1.5:3 would give dimensions along the outside edges of 16", 24", and 48". This could fit inside a small masonry bell just as well as the tiny dimensions you mention. You would need a part
and the polystyrene underneath the rmh instead of rising it above the wooden floor. From my plans the combustion unit could have a 10,5" feed, a 20" burn tunnel and a 38" riser. The stovepipe inside the mass would
I had a drop tube (pipe penetrating the top and extending to about 3” from floor height) acting as my outlet from my stratification chamber since there was no room to come out from the side.
On the end of the drop tube I made a funnel to help direct the cooled flue gasses into the exit pipe. The funnel allowed me to be closer to the floor to maximize the most heat extraction.
For a side exit, a funnelled end would help just as well to direct the gasses into the opening easier. The gasses
Thanks Gerry! Now I get it, this stratification chamber is super cool and actually fix a few problem! Matt was mentioning a smaller footprint design, I guess it would be to do a vertical stratification bell? Also what about the CSA? is the stratification bell's outlet the same than the feed? Exit chimney, etc.?
As I mentioned a few time I'd like to use it to heat my central heating water.
Main issue with the fire is the burst of temperature. If I was having the coil pipe on the top of
[quote=Julien Vailles]
I don't fully understand the different of the stratification bell and the bell used for a RMH (when using an airtight metal drum).
I have attached the diagram. Isn't[/quote]
Also I know RMH can heat water (and it is dangerous). As I have already in place a central heating working currently with Aga + oil.
I would ideally like an RMH that could also heat up my central
.
A traditional RMH like you are thinking to build, uses horizontal pipe sitting on insulated cob, surrounded by more cob and large rocks with no air gaps.
Often this mass is finished in cob shaped
bells" - I tried to search on the forum, no luck.
But not needing a mass and pipe would be great, my wife is not too happy about the space required by the RMH mainly because the current setup
Thanks a mill for your answers Thomas, very useful to me!
It will be a J tube in fire bricks so I should go with rock wool - mineral wool.
HVAC pipe is a ventilation type pipe, right? No regulation here.
I found this for the exit chimney flue, I need a flexible one as there is at least one bend and I don't know what else, it can support -30/+150 degree, I think it should the job flexi item - What do you think?
Hi Julien;
I'll try to answer some of your questions.
You want an 8" Rocket, are you thinking of a J tube or a batch box?
The eBay flue liner is much more than you need unless you must meet local installation regulations to use a wood burner.
The pipes in your mass can be a very light gauge, You will cover them in cob. No need for stainless or even standard black stove pipe.
I used 5' long sections of HVAC pipe in my mass, which was very cheap.
I used one piece of black pipe for
Batch box mass heater.
Left to right paper for riser warming fire, cardboard wich to help flame move from paper to tinder, tinder, kindling, small wood. Paul asked us to burn ugly wood and bark so we'll see how much of the box I can burn in an hour.
The water on the floor is me trying not to set the broom on fire when I sweep the escaped coals back in.
This is the batch box rocket mass heater in the classroom at Wheaton Labs. Works great! In my florida opin this was needed on this rainy day. It was about 50deg in the building before lighting this heater.
While at Wheaton Labs for the 2022 Rocket Mass Heater Workshop, I started the batch box RMH in the classroom. It wasn't too cold outside so it wasn't necessary to add more wood within the hour but I
o pic of starting materials, PROPERLY placed in the batch box before fire
o pic of fire started to warm the riser - at the back of the batch box
o pic of additional wood added
o pic of even more wood added
Starting materials placed in the back/bottom or riser
https://permies.com/t/129262/a/175829/thumb-300_20220424_190326-01.jpeg width=300
Here is my submission for the Rocket - Sand - Start and Operate a Batch Box Rocket BB.
As the SkIP event winds down, I headed to Cooper Cabin to light the rocket batch box there.
To document the completion of the BB, I have provided the following:
o pic of starting materials, PROPERLY placed in the batch box before fire
o pic of fire started to warm the riser - at the back (left) of the batch box
o pic of additional wood added
o pic of even more
I now realize I misread the first requirement of a "pic of starting materials, PROPERLY placed in the batch box before the fire." Looks like I mistakenly took a "pic of starting material before fire." I mean, properly was even all caps.
Placing the pics here anyway. It's a very nice heater for the classroom.
First time using a rocket mass heater. Really enjoyed it and liked learning about the way these operate. It did great no smoke out of the door and the priming caught the small tipi initial fire so it helped to get it primed and hot enough to start sucking the smoke in more aggressively before having to open the door to add more wood.
After two unsuccessful operations of the cyclone batch box heater in the Red Cabin, Paul suggested checking the chimney for blockages. Sure enough, it was 75% blocked off by ash. Cleaned out the elbow, cleaned the pipe, replaced the elbow with a tee and cobbed it in place. Started it up and it was worlds better.
Hi E;
I am not a fan of CFB anywhere it can be abraded.
I have tried it with J tube rockets and as roofs on numerous batch boxes, it has failed miserably every time.
However, away /protected from abrasion it is a fine insulator.
I am a fan of using heavy firebricks for cores.
My Walker BBQ uses the same riserless core that the tiny cook stove does.
I built it using heavy firebrick. I love it! However, it is not easy to start.
It can and does create clouds of smoke. As this is an
Those panels sound huge! The ones this company makes for residential use are 4x8 to 4x12 ft I think.
Sounds like Matt will be an important resource for this. I am not set on using or not using any specific materials at this point. Just exploring options. I know bricks must be here somewhere, but I haven't found them yet haha... I can find pavers and cement block, but standard bricks are harder more difficult. I havent checked anchorage yet though. There are more options
Hi E;
I guess I was working with industrial-size sips.
The wall panels were 42"x 26' tall and the roof panels were 42" wide and 53' long, they weighed over #600 each...
So let us start with the reading material.
Both books are full of good information and always worth reading!
A local library or bookmobile might get you copies to read during the winter.
Neither will help much with a Walker riserless core.
Matt's design is unique to his stoves.
Also with the popularity and convenience
Final question: If we go with the Tiny Cook Stove, I intend to buy Matt's plans. Would either of the RMH Books be a worthwhile addition for that build? Or is the batch box design of the stove
that you're wanting an RMH in your new home.
With a smaller footprint and the super-insulated building, it will not take much to keep it warm.
An 8" J tube will burn for 45 minutes between loadings.
A 6
[quote=Eloise Rock]If anyone has a suggestion of a more natural option that can be built quickly and cheaply, and withstands a wet and cold climate well, I'm all ears.[/quote]
Generally quickly and cheaply don't go together when constructing a natural house. They are often a labour of love that ends up taking a long time to build, but the end result is often well worth it. For instance, earth bag houses are often quoted as being 'dirt' cheap, but if you've ever built one, it takes a lot of
I know I need to read up more on technical aspects before attempting any builds. Given my scenario, what resource would you recommend? I know of the Evans book, Erica & Ernie's book, the Donkey forums... I have only looked at the donkey forums a time or two, and found them over my head. So maybe I need a book first?
Are you concerned the house will get too hot?
Have you studied the use of SIP homes and got an understanding of them?
Can you speak with people living in them?
I assume its a 'summer' house for weekends etc, have you considered LPG cooking?
Perhaps look at this;
https://www.houzz.com/discussions/2269739/anyone-live-in-a-sip-home
Hello,
I have asked some vague questions on RMH stuff before, but our plans are evolving and slowly solidifying, so I have some more detailed questions now...
My general plan is to install an RMH in a (6m x 4m) sunroom that opens up to the rest of the house through 2 large doorways.
If convection becomes an issue I will install 2 small low speed
a platform next to the current placement and plan out a RMH within that space. I had the platform 95% done and the skeleton of the RMH laid out when the ground took on a frozen state for the season
looking at right now are to lay out a pallet frame and build off of that, or to put the RMH on or slightly in the ground and work on an insulation scheme down there.
all along has been to put at at least 2 supports up to the ring in the middle and to build some sort of loft off of the side of them. I was waiting to feel out how the RMH would take shape to design
? At the RMH Jamboree I was being encouraged to dig drown around the perimeter and install insulation (foam boards?) around that trench edge. I figure I'll do that at least for drainage, but anything to do
I'm hoping to burn extra wood to compensate for a cold earth floor, but any suggestions on mitigating that heat? At the RMH Jamboree I was being encouraged to dig drown around
[quote]Here's a photo of Grey building the first version of the "oven hat" on top of the RMH in the Love Shack today. This is an experimental design, with the objective of simultaneously directing heat[/quote]
[quote]Here's a photo of Grey building the first version of the "oven hat" on top of the RMH in the Love Shack today. This is an experimental design, with the objective of simultaneously directing heat[/quote]
on your feet and keep on driving.
I can see a car repair show on the back woods of Montana called Tom's garage.
Having an RMH blazing in the background with a blizzard of snow seen through the window
![[Logo]](https://permies.com/mooseImages/permaculture-gardener-edited.png "permaculture gardener clear text")
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