As an ex-boilerman in a local Sawmill I can tell you the worst thing that can happen to the feed line is fire creeping up through the fuel and reaching the storage bin. We had that happen a couple times and it was very difficult to extinguish. The vertical door that you installed will help but a vertical separation from the storage bin to the sloping feed tray is the best way. A door at the bottom of the storage bin that lets fuel fall into the delivery tray ensures separation and so that fuel doesn't build up in the feed tray. Vibrating the sloping feed tray ensures fuel goes all the way down each time your control system calls for fuel. I know it sounds more complicated but you can't be too safe. A fire in the fuel bin could be disastrous. That vertical door that you used is also a very good idea. Nicely done project!

The 2nd most viewed video this year triples the views of number 3! With 264,007 (268,862 total), it was published at the end of last year. It shows some extreme enhancements we made to the rocket mass heater to try to extract as much heat as possible from it. I'm still burning pellets in it without any issues...but I am currently working on a new design for next season! Rocket Mass Heater - On Steroids

yup. I've been trying to find one that has enough static pressure to push the air through the piping. They aren't very powerful. :(

Somebody give this man a cookie! And make it a golden one! As thanks for excellent home-engineering contribution to mankind!

This is fantastic. I'm interested in both aquaponics, and rocket mass heaters, so finding y'all is gold. Thank you!

I've been researching this for years. this is bar none the best design and video I've seen. Well done.

this looks great. good job explaining the reasons

Nicely done! You've done a great job not only with the build but with the video. I enjoyed it!

Just WOW!!! Thank you soooo much for sharing. 5:50 I appreciate all the temperature measurments as well as the care you took to avoid sun radiation to interfere with them. Alex from Québec, Canada

, brilliant. I love the way the rocket stoves continue to evolve. I feel like we're just beginning to scratch the surface or what's possible.

I love it when a plan comes together

You could use attach a peltier TEG generator on top of the warming radiator, apply cool water to the other side of the peltier module, before it enters the radiator, and use that resulting DC to power that fan.

what a convoluted fantastic design! I will likely never be able to build my own place. I've watched time on videos on earthship and dirtbag houses. I like the relative freedom of design theoretically. it was actually on one of the earthbag videos I saw them talking about a rocket stove. if never heard of it. I tried to find what in the world it was and why it was better but alas my google-fu failed. then today KZfaq randomly out you in my list of might likes... and i liked it. thank you so much for explaining your system. it looks like a great design and I think it's awesome that you keep finding ways to improve!

This is an amazing accomplishment. I'm glad their are so many brilliant people like you for me to try and copy. Awesome.

Great work sir

thanks I hope to do something like this for my greenhouse & lots of the rest of my farm. nice to see drawings & facts how it maybe similar.

Love your videos! I'm a California guy who is moving way up north... Edmonton AB, Canada... My wife's family has a big chunk of land that we are going to start a farm on. I see me building something like what you have done at your place so your video's have been a wealth of information. I have done Hydroponics for years and have had Fish tanks most of my life so aquaponics is a natural match for me. Ill be sure to share once I start building. Keep up the good work.

Awesome and innovative system! love the idea of pulling heat for my aquaponics system from my greenhouse stove... great job! thanks for sharing!

Very cool design man! Thanks for sharing! Looking forward to updates!

That heater is producing as much heat as possible without continually increasing the wood charge. Built with readily accessible parts. So well thought out. Two thumbs up !!!!!!!!!!!!!!

Very nicely done. The efficiency is impressive. I can't wait to see your new RMH for next year

Impressive, thanks for all of your effort

Interesting setup. But I would not use a box fan laying down. Most all have sleeve/thin bushing mount for the motor shaft. Its made to be run with shaft horizontal. Those mounts will wear out soon or cause motor to run with friction as the weight of the stator and fan blades push downward.

You have one heck of a setup there! Been enjoying your videos on your RMH! Keep up the great work and videos! Thanks for sharing!

Great vid - i have only one comment on this design: you may want to consider a heat exchanger at the aquaponics location to exchange heat to the water the fish are in. Fish emit nitrates as waste and these nitrates will corrode any metal parts in your system. The heat exchanger for the pond will need to be a material that can tolerate the high nitrate concentrations - such as a plastic unit rather than metal - since it is submerged in the pond it will not be subjected to very hot water. I have seen some systems that combine the pond with a plant hydroponics set up so the plants extract the nitrite nitrate and ammonia and this also helps the fish.

I'd love to see your hammer mill system. I've been looking at various models. I'm pumping a little over a gallon per minute through the radiators. It doesn't take much flow to keep them from boiling.

Brilliant design youve come up with. you thought your way till the end. Nice choice to incorporate the heat at different Temperatures to their designated tasks.

Really nice set up on your dome. In this video you mention that it will still get colder in January; Another way you could maintain some of your heat in the dome would be adding a heat exchanger inside your flue. Old gas water heaters had a central chimney running up the center of the tank, inside this straight pipe was a spiraled piece of metal. Taken out of the flue it is simply a straight rectangular sheet of metal with regular bends to create a spiral effect increasing surface contact. if the fit is snug enough it could be drawn through the flue with edges touching the full length without having to weld it the whole way. Doing this along the length where you have the 10" cover with fan could give you a few more degrees. The same process also goes for between your flue pipe and the 10" cover pipe (with fan). The longer the air circulates across the hot metal the more temperature you will retain. Also, while I don't know the soil content of the greenhouse floor, if you want it to absorb and transfer the heat a little better don't let the ground dry out, moist soil keeps a better temperature when the air cools off... Though depending on where your runoff goes the ground may have plenty of moisture. Also curious what temperature range your fish tank goes through day to night, while I don't know much about the biology of fish I do know the water temp affects their behavior/ feeding habits, etc.

I love your pioneering approach ! I’m very interested in watching further developments and refinements to measure performance.

i like it when maintenance men make systems rather than engineers. I've busted open hundreds of feet of concrete to get to steam lines in the earth and under the cement floor. When things get corroded or if something breaks down, you'll just be going to home depot all the time. I'm super pessimistic about anything complex. When thinking about sustainable energy and locally obtained fuel, simplicity and locally found maintenance material is a value much higher than convenience.

Very well thought out! I'll definitely be taking inspiration for my cobb house to be =D

Yes. I'm currently working on a new design that can deal with wood chips.

Excellent video. I was hoping to build the same thing for my house. Thank you for sharing.

Great video. I was trying to find an idea to heat hot water and use the exhaust air to heat the air and i had thought of using radiators with fans to do it. your video seems the closest to my thoughts but looks like a very involved build

Finally! A crazy invention video on youtube in High Def! Thank you!

Thanks for this update!! You've helped me so much with my own greenhouse rmh-watching what worked for you and what didn't; I changed my original rmh idea after seeing how well the pellets worked out. I am currently working on making my own hammermill/pelletizer. (my welding isnt very good either LOL) Radiators are a brilliant idea! How many gal/min are going thru the radiators?

Awesome. First video I've seen of someone utilizing every bit of heat generated.

I like your ideas and application. great video, keep up the good work

Awesome! Just Awsome! I was trying to come up with a way to heat my system with coils in the ground. I never thought of radiators. Thanks for the idea! Keeping Tilapia inside all winter is becoming a pain in the arse.

Having some of the heat "leak" into the building actually works out well to heat the space. It's a fairly good balance between heating the water, air, and mass.

That was informative as hell , great job .

I use cold outside air, coming in thru my ash pit, rather than already heated room air, to feed the firebox. It means less lost room heat, and cracks & room vents don't tend to pull in cold outside air. You have the pellet chute as well, but that could be sealed with leather or plastic. I found this to make a huge difference in the comfort of peripheral areas of the house.

Excellent work, excellent video. Thank you!

Excellent vids. Best explanation and probably mods of rmh I've seen. If one were to use pellets vs wood, is it worthwhile for time/energy to home-make from leaves etc, or do you just buy them? Thanks man!

Excellent video.

Kudos to you both, I must say.

Good Job! I love the way you speak with DATA..it beats talking out your ..bleep..every time!

Amazingly awesome or awesomely amazing! I can't decide which.

You have spent a tremendous amount of time and effort I think it has paid off Great vi

Brilliant build advice thank you

nice and cozy all over the green house area due to underground heating system, love the idea, nice...

did you just use a regular vehicle radiator for the heat transfer? im running a rocket stove and want to add a radiator system to heat water for the house, do you think this is feasable? thanks for the video, its really good

This is very very interesting indeed- thanks for sharing this

it would be a good idea to wrap your exhaust stack tube with copper tubing and run water through it to heat more water, why waste the heat

I've never tried to bypass any of the rafts to heat just the fish....I just wanted to avoid having the system too complex. I have to be really careful not to heat the water up too much over the air since it will start to condensate too much. I already have a problem over the winter with powdery mildew when it gets too humid!

Your filter for the water from the auqaponica to the radiators could benefit from a sump tank. A small tank where the water, after being filtered, flows freely into, and allows any unfiltered sediments to fall out of the water before the water continues into the radiators. :-)

keeping the dome in the 50's over the winter is fine for the plants. I didn't want to make it more complicated to run. The ground mass has been slowly raising in temperature the more I burn. That was sort of the goal I was aiming for.

This is excellent. I love this Idea. May I suggest holding seminars at the Mother Earth News Festival. They had a person doing the rocket furnace stove there last year. If you can combine this with the aquaponics you mentioned, you should have great success! I am going to keep a close watch on your upcoming videos and probably use your build in the near future. Thank you so much for this video!

I love the way you have utilised different methods to extract and use the heat. Just wondering though. If you used metal for the barrel and underground piping, would you not get a better amount of heat transfer? Also, are the fish edible, and what do you feed them??

Thank you Sir for your efforts to educate me

Excellent modifications

It worked well over the winter. I did another video about pulling it apart and doing some repair work. I have a new design I'm working on this summer and will do another update late this year.

Cool channel, enjoy the vid's. Im thinking along the lines of a wood gasifier, heat exchange water heater (to cool/condense wood gases) via rocket stove. In other words I'm interested in utilizing the advantageous characteristics of the rocket stove as a mass heater, and heat exchange to heat water and also to cool/condense the combustible gases all in one configuration. Does the rocket stove produce combustible gases? Or perhaps I should ask at what point on the rocket stove could I tap to siphon off the combustible gases? SemperFi

Great job. Thank you

Interesting thoughts. Luckily I've never seen my water get into this pH range. But, it may be a good idea to make a couple of small design changes to make the heating system on a closed loop. Thanks!

I grew up with a wood burning stove for a heater that my dad put a 55gal drum upside down over & let the exhaust pipe run through it to catch radiating heat & pump it to the rest of the house via a squirrel cage blower & 6" pipework along the ceiling. It worked great but not as efficient as yours... But then again were in Texas so it didn't have much to contend with. I was always trying to make it more efficient though.

Does this give enough time for the air to 'cook off' the rest of the exhaust. My understanding of the way rocket stoves work to get maximum efficiency is that they continue burning the smoke while it flows up. It would seem to me that the radiators would be sucking out too much heat from the burning chamber.

I am considering using Miscanthus giganteus as my rocket stove fuel. Its a perennial grass hybrid that grows 3/4 inch canes 8 to 12 ft tall. Take 10 or so canes and stick it in the rocket stove and just let it burn down. Great stuff, love your work and thought you are putting in to your systems.

Will you share your plans for this set up? I would like to repeat in in Wisconsin.

a few things - if you cross break those sheet metal panels, or add a hem to the edges, they will be a lot stiffer and stay flat. if there's a local sheet metal shop they can probably do that for you. also, any time you have a wood fire and you're trying to remove heat from it, you have to be careful because if you strip the heat from the exhaust gases then they can condense inside of the flue pipe. all the tars and resins (which turns into creosote) will clog up if your flue gases are less than 200 degrees. unless, of course, you're able to get 100% combustion in your stove, which is possible, but on start up and shut down you will not likely be able to get 100% combustion, as the system is not hot enough.

great job man

this is really neat, dude.

Thanks for the video. Am having some thoughts on whether there is enough air flow through the rocket system to propel a small fan to produce electricity? - Like a mini wind turbine but driven by the natural air flowing through the system? - What do you think?

wow that's quite a system great build

It's hard to split wood that's over a couple of feet long. My splitter only goes to 24 inches. Wood tends to jamb in the chuts with their uneven knobs and sticks. If you get any back draft, the flames come up and it can come out through the feed area. It's very difficult to put out the fire once these start to burn backwards!

Hey there , I gave you a thumbs up for the design , work , innovation put in and learning you must have done in the project. I always appreciate some one who adds to the conversation in a meaningful way. The amount of BTU out put will always be limited by the amount of fuel burning at one time and the amount available in chosen fuel. 8000 btu per pound of hard would at 10% or less moisture. Not sure about pellets. Area of wall surface area divided "R" value of the wall then multiplied by Delta "T" ( desired temp difference needed on coldest day) will give you BTU's required for a structure . IN water it takes about 1350 BTU to heat one gallon from 40 to 180 degrees. Last exhaust temps should be kept a little above 200-235 for good draft and to prevent gases from condensing in the chimney that will cause build up of creosote, thus the myth that a rocket stove can heat your house on sticks from the yard. IT cant that wood is not dense enough or dry enough does not contains sufficient BTU out put to heat a house because there is not enough of it on fire at one time releasing the energy required.

Sorry, I don't have any measured drawings of this...just what I show in the video.

yup. The radiators are easy to remove so I could do this. There's no doubt you want to run them dry! I can also let more heat right into the air by removing one of the panels which changes the air flow. It's not hi-tech like a real heating system, but it will do the job!

I really like all the heat exchange you're getting. I think you might be losing some heat to expansion, going from the riser to the next chamber. That might explain the 10-degree temperature drop in the diagram.

Did you add a means to control the water's temp? Probably would want some electronic mixer to ensure that the water won't scald the fish or raise the temp of their water too quickly.

So, whats the update for this winter? How did you manage? Is there a video about it? Great work, thank you!

Thanks. I've been doing a ton of research on making pellets. My goal is to run this year on purchasing them so I can see how much I'm going to need. Then I'll figure out if it's worth the cost & time to make my own. I would love to be able to. The biggest problem I find is that the smaller mills aren't really designed for wood, but mostly grass/leaves. I rather do wood since I can get truckloads of chips for free!

What an amazing mind you have.

Have you experienced any corrosion inside your radiators? What's your typical pH levels? What material are the radiators made from? And what purpose was the radiators originally for, if auto then how did you clean chemicals out of it.

Great work!! 7 years later (thanks youtube!) just a question of concern I have: Taking away flue gas heat could bring down the due point of the moisture in the gasses causing it to condense and turn into water. Have you had any problems with puddles of water at the bottom of the flue, and thus corroding the flue pipe? This can be seen in condense boilers that have to discharge the water frequently.

I am wanting to do the same type of thing with the hot air in the top of my greenhouse. I plan to hang a radiator up in the top of the greenhouse. I was planning to make it closed loop system as the radiator is aluminum. I think that the best tubing to use in the fish tank and/or slump is PEX with aluminum in the middle. It has PEX on the outside and PEX on the inside and aluminum in between. This is used in in floor heating systems to spread the heat out.

Elegant, bravo!

Surely you can adjust the flow of pellets by fitting a 4volt worm screw electric motor and controlling by a room thermometer?

nice video / project ! Keep up the good work.

the hammer mill pulverizes the wood into sawdust, and then you can feed it into the pellet mill. (they aren't able to grind up material, just compress it together)

Beautiful design! One thing I'd add: PLEASE make sure you have a carbon monoxide detector when making a home-made heater. One small design mistake can cost you your life.

The water will boil out of the radiators and the heat just domes out of the cover. It's happened twice now. Usually if we lose power, I usually run down it shut it off before the water boils out.

How about referencing your source??? This heater does exactly what I need it to do..puts heat into different systems from the one unit. I have no problems using external power source on this heat to accomplish this goal.

I frigging love your commitment to your project! Your video gives me motivation man! Although, i do not understand from a thermodynamical point of view why you complicate it to this level. Basically what you have put so much effort in to build are heat exchangers. Don't you think its far more efficient to use two old heat exchangers from a scrapyard than to build them yourself?

The Blue Tilapia I have are rated at 50-55 degrees for survival and they start dropping at 45. When the temp hit 60 I started moving them into the living room. That move took out 22 of my biggest because I didn't have enough oxygen or filtration. Obviously, I didn't think this through. So back to the drawing board for next cold season. I have a neighbor who is trying an in-ground RMH in a Green house. That may me my solution. I wish I had your forethought or research skills! Love the vids!

Hello, you will want to use the exiting excess heat to preheat new cold incoming air in the winter. This gives you a higher efficiency of the system and a higher room temperature. Nice job!

nice video very well put getter with all information and stuff

Maybe an idea, i would have used stonewool inside de casing wer you radiators are this prevents cooling the hot air. in the cabin

It's about time someone moded a rocket mass heater! I like your design and I don't think I could have done better. I am only concerned about the operating costs of pellets and wood. By lining the inside of the dome with some Mylar you can reflect some solar heat into the fish water.

Do you make your own pellets? If so, what do you use to uh "pelletify" them?