Building a J Tube Rocket Mass Heater
This short video of still photographs documents the building of our Rocket Mass Heater in 2015, the changes we made to improve initial performance, and the maintenance (and changes) we carried out in 2019. Our first (partial) build in 2007 was easier as it was a workshop with a group of people which made it much more fun. This build was quite hard work for just the two of us (over 60's), but not impossible and totally worth it. It's a very efficient form of heating, much more efficient than the 12Kw traditional wood-burner it replaced. I don't think I would ever willingly choose to live in Northern Europe without a rocket heater and I totally recommend it if you have the space. In 2021 we finally added the lime mortar coating.
This video was produced as evidence for permies.com/wi...
You can find more information, free resources, DVD's to buy and experts generous with their knowledge to help you with your build, on the Permies.com Rocket Mass Heater forum, and the DVD's I showed my husband, which convinced him to do it, are here: permies.com/wi...
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I have only begun my first attempt at a rocket, although I have read and KZreadd and dreamed for many years. Circumstances are finally favorable. To be free to make mistakes/adjustments, I am starting in my downstairs "shop" area. Then I shall be confident enough to try something as gorgeous as your creation. How lovely! You and so many who have contributed to my dreams are amazing. Thanks for sharing.
@lesleyv5923
2 жыл бұрын
Hi Linda, Thank you for your kind comments! I wish you the very best with your build. My advice is to stick to a tried and tested build - plans from Erica and Ernie wisner (on permies.com) or Iannto Evans (with three updates: lose the small barrel arounf the feed tube, add the 'v' on the burn chamber roof, and add a metal plate to feed tube for air intake and to protect the burnchamber roof firebrick) once again look at the permies.com Rocket mass heaterforum for lots of assistance. This year, at long last we finally found time to put the lime mortar coating on the cob, so I need to update the video. I'm pleased we waited (didn't find time!) because we've changed the shape and decorative elements since we built, and that would have been more difficult if we'd had the lime layer to remove each time.
what a lovely job you did
@lesleyv5923
Жыл бұрын
Thanks for the kind words Richard
Les beautiful bench! I need to build one in France too!❤!
@lesleyv5923
Жыл бұрын
Thanks Ian, where are you in France?
great job and thanks for sharing the challenges you encountered and how you overcame them. this should help many people.
@lesleyv5923
Жыл бұрын
Thanks for posting, I'm pleased you enjoyed it.
Wow, starts crazy fast!
@lesleyv5923
Жыл бұрын
You're right! Never ceases to amaze me!
Looks awesome. Wonder if it could be built with the burning chamber in another room or closet.
@lesleyv5923
6 ай бұрын
Hi Stefen, Thanks for watching. Your best place to ask that question, for a technical answer, is in the Rocket mass heater forum over at Permies.com! Bear in mind that the nature of the RMH means it needs feeding whilst it's firing. Not so easy if the feed tube is in another area, presumably in a colder area too!? We fire up for about 1hr to 90 mins whilst we're getting on with other stuff. We can hear when the sound of the firing changes and we need to add wood.
That is amazing, well done. I am wondering if you ever examined what came out of the chimney on the roof, was the gas warm? If I ever build one I will install an inline extractor fan at the chimney end in order to pull the air while starting the fire to reduce any chance of smoke in the room, but of course the mass has to extract most of the heat so that the fan is not damaged when the burner is in full swing
@lesleyv5923
2 жыл бұрын
Hi Nick, thanks for the kind words, and I'm pleased you enjoyed it. Once the fire is up and running 'rockety' (takes about 5-10 minutes), there is nothing to see coming out of the chimney as the burn is pretty clean. We have a thermometer on the chimney as it exits the mass and that's running at around 80ºC I've put a thermocouple at the bottom of the feed tube and the max I've had is 700ºC - That was with split oak heartwood. We use a mix of branchwood and split oak. The former is less effort as it goes in as is, but gives less BTU's, and the latter needs splitting (though when the fire is really hot we'll put a big log on!) but burns hotter. It's a trade off! You definitely do not need to install an extractor, trust me! Just follow the instructions to the letter for your first build, and you'll have no problems. The first firing of winter, the air in the mass is 'stagnant' so to get it moving upward, we open up the clean-out that's next to the 'up' part of the chimney, and burn a candle to warm the air, before we light up. You could also use a hairdryer on the chimney pipe. Thereafter there's absolutely no smoke in the room, because the mass never gets cold, and warm air always wants to rise. As soon as we take the cover off the feed tube, you can feel the draught pulling into it. (in fact, if it's really cold outside I have been known to open the cover and sneak a quick cigarette - the draught pulls the smoke in!) The only time we had smoke (and so much it looked like the house was on fire:o) was the first firing after we completed the build. I panicked but the experts on Permies.com said it was normal, everything is so cold and damp, it takes a bit to get the air moving. We originally had a horizontal section running through an outbuilding and it was just too long. We connected to the original woodburner chimney thru the roof and this gave it the help it needed. We never got around to changing it back. I cannot sing too highly my praises for the info and support at Permies.com, as well as the videos and plans that are available there. We're going to build a rocket oven and a rocket fired cooking hob as insurance against future gas and electric supply problems. Love the Avatar btw!
@utubeape
2 жыл бұрын
@@lesleyv5923 thanks for the very thorough reply. I am also thinking of having a Y shaped manifold with a door that can close off one of the tubes, and the tube not going to the mass will have a copper coil surrounding it, filled with water, this will be my water heating system for the winter when solar water heating does not work. As soon as there is enough water stored in the tank I will close the door on the manifold then divert the heat into the mass
@lesleyv5923
2 жыл бұрын
@@utubeape My initial thought is Squish Boom! Water and fire are a dangerous combo if combined in the wrong way! so, get over to Permies.com to talk with one of the many guys who are enthusiasts. They are good. Paul has a set of five fire DVD's that could help. My advice is, for your very first rocket, stick with the tried and tested. There are also designs on permies for rockets that heat water. Remember when two functions are combined into one piece of kit it often performs neither very efficiently.
so u have a schematic of final ratios/dimensions that worked best? i am going to be adding these to my cottage builds and want maximum efficient lengths etc first time as o am getting a bit old for do-overs.
@lesleyv5923
7 ай бұрын
Hi, Invest in at least Ernie and Erica Wisners' book. All dimensions and tips are in that. The book I used was the Iannto Evans Rocket mass heaters, which was excellent. E & E have improved on the plans. You can find them on Permies.com Money worth spending so that you'll end up with something that works first time. This is quite an undertaking, it's gutty work, I cannot understand why some people want to re-invent the wheel based on watching a few youtube vids and a wish to create something 'unique' You're wise to want to stick to tried and trusted. Best of luck with your build.
my advice to anyone about to try these? do it outside. just slap a bit of mud on the seams so its airtight, and so its easily torn apart and redone. experiment with the burn chamber first. get that to work, sort out the bugs. as long as that works, and your flue is sufficiently large on the real deal... it will work exactly the same. you dont want a bad fireplace inside... you definitely dont want to have to pull it apart. after the burn chamber, you never want any reduction in cross-area... always expanding if possible. ive been playing around with a toroid burn chamber, more like a brick pizza oven. air entering tangentially, flames always "biting its own tail" with a lot of circulation in the chamber before finally heading up the flue thats about halfway up the chamber... they barely smoke as it is when done properly, this just seems to take it to a new level. doing exactly what i advised not to do... pulling the existing burn chamber apart for next winter... (AU)
@lesleyv5923
9 ай бұрын
Hi, Thanks for your comment, which is a really good idea for anyone wanting to experiment and create their own version from scratch (Though I'd say why re-invent the wheel?!) From my personal experience, if you follow the instructions in the Wisners' book, you'll have an efficient and safe rocket that will function as advertised. There are lots of DIYers on you tube, doing 'interesting' stuff but often don't follow up with the 'what went wrong'. If you have the time and interest, rocket burners are fascinating to play with. We just wanted something that worked, so just followed the instructions. At our age we didn't have time energy or money to play around when we could follow the wisdom of those who have earned their laurels in the field.
Hi, Fox James here, I dont think I have ever seen your video before, well done, great job. How is it all working a year on?
@lesleyv5923
Жыл бұрын
Hi Fox fish, Many thanks for your kind words, and my apologies for the tardy reply. Things have been a bit challenging here, but life is now quietening down and I'm working through a backlog of correspondance. All's working very well, and we're now into our 7th year. I'm really pleased with the final rendition - it's easy to dust, (unlike the original 'curvy, organic' version) the extra mass over the manifold brews Kombucha really well, and the steps we incorporated, make it easier to get the kettles off the top! I'm pleased we held off adding the lime mortar layer for so long, as it made the changes so much easier.
Nice!
@lesleyv5923
Жыл бұрын
Thanks!
I would love to form up and pour one of these from concrete but I'm not sure if it has the same heat transfer characteristics as cob.
@lesleyv5923
Жыл бұрын
No!! definitely do NOT use concrete! It wont withstand the heat/expansion. My advice is, dont try to re-invent the wheel! If you've never built and operated one before, just get the books (Iain evanto or Erica & Ernie Wisner) follow the nstructions and you will have a reliable, amazing heat source. After you've successfully constructed one, hey, try out your ideas! At the end of the day, this is not a small, quick thing to knock out. After all the hard work, you want it to work ;o)
@jasonfoster9118
Жыл бұрын
@@lesleyv5923 I mean the thermal mass. Concrete (the real stuff, not the sandy sackcrete junk) is routinely exposed to temperature ranges within those that the thermal mass would be subjected to. I'm a construction worker and there are endless possibilities for pouring benches, troughs, beds, etc. They could be filled with sand, gravel, water or just about anything that holds a lot of BTU's. But, after researching the idea, a RMH really isn't practical for my situation. It looks like a lot of fun to build, though.
@lesleyv5923
Жыл бұрын
@@jasonfoster9118 aha Phew! Shame you can't fit one in, they really are a treat in winter, and we open her up in the summer for passive cooling of our barn. Anyway, to anyone reading, interested in using alternative materials for the mass, have a look on Permies.com, there's a video there of Paul Wheaton's rocket with gravel mass.
Would be nice if this was instructed
@lesleyv5923
Ай бұрын
There are already some great vids with instructions. This was just collated as evidence for permies, as explained in the description.
Hi Lesley, I'm reaching out in response to your comment on the asha logos video. How can I contact you?
@lesleyv5923
Жыл бұрын
Hi, you can email me at Admin1FP@protonmail.com
The video is way way to fast. Impossible to follow all the changes and how you improved it's function. Please slow it down., Explain each step and the lessons that you learned. 2 second snap shots of the building process with canned music doesn't teach your audience how to do it..........
@lesleyv5923
Жыл бұрын
Hi Eric. If a video is too fast, go to settings (the cog wheel right of centre under the video) and change the playback speed. You can also use the pause button ( two parallel bars " II " far left under the video when it's playing) to stop at any point if you want to look closer. The canned music is copyright-free and can be muted using the speaker icon to the right of the pause/play button. I'm a qualified teacher. This is not a teaching video, it's a record of building our J tube rocket as evidence for a badge-bit on Permies.com and offered here for anyone interested in the subject. I recommend Eric and Ernie Wisners books and plans for the detail needed to build one. They are here: permies.com/t/40993/Ernie-Erica-Wisner-Rocket-Mass.
@vincentbalintucas1890
Жыл бұрын
Awesome set up. How would you clean all of the manifolds?
@lesleyv5923
Жыл бұрын
@@vincentbalintucas1890 Hi Vincent, There are 3 access points one is for the manifold, two are for the mass. once a year (in the summer) we do the big sweep - using an 8" diameter chimney brush with very flexible rods, plus a cinders vacuum to clean her out. (Dont use a domestic vacuum it can't handle the dust - dont ask me how I know!) The main manifold (just after the barrel) is cleaned out mid firing season. At the 4 year point, when we opened her up, the ash build up of the areas not accessible, wasn't that great (great relief!) I've seen some versions where there's a clasp lock joining the top barrel to the base barrel section, which would make it a cinch to clean. We couldn't source a clasp lock thing that would connect the two rolled rims here in France. If you keep monitoring to fire clean, by keeping the wood topped up all the time and don't let the temperature drop, it greatly reduces the ash in the system. If I did it again, I'd definitely add another access point just before the bend at the end of the bench!
@vincentbalintucas1890
Жыл бұрын
@@lesleyv5923 thanks for the reply. I came across your video after watching some Korean ondol systems, where they light a fire and the heat spreads through under through some channels underneath a home. These look very efficient.
@lesleyv5923
Жыл бұрын
@@vincentbalintucas1890 Far too often nowadays, the old ways are thrown aside to make way for 'stuff' we have to buy, that's too complicated for us to repair! Clown world ;o)