It would’ve been way better if you just made it like this instead of that. Next time try changing that piece to this piece and it’ll be much better, trust me
As with most things in engineering, usually maximizing efficiency in one variable decreases efficiency in another. In this case, fuel efficiency vs. time efficiency.
thermally speaking,if the tube surface used where to be the same, the square one would be better because the tube is directly exposed to the heat making it easier for the heat to exchange between the water and the heated air.Whilst the round one, only part of the tube surface is in contact with the metal so the heat has to transfer from the heated air to the metal,conduct the heat through the metal and finally jump from te metal to the copper. Trapping the hot air around the tube with the insultaing tape helps on the efciency but the square one is defintely the winner here.
also the square stove has a way bigger gap for the air to flow in,making it more eficient in burning fuel. Thats why it runs so fast out of wood. Although we could argue if that's beneficial for the exchange of heat. Maybe limiting the opening on the air gap to slow down the combustion would make it better.
That's what I said. Pump is circulating and mixing the water in the bucket. Goes so far as weighing the wood to be equal then uses a pump in one and not the other.
I had started getting much better results with my rocket stoves after surrounding them with galvanized half inch mesh wire double layer and then making my own refractory concrete mix with perlite which is insulative. The results are insane. The stack is super insulative which makes the internal combustion much easier and more ferocious and more efficient
I've never used perlite.i use vermiculite. 5 to one ratio with cement and a bit of sand. I made a pizza oven 7 years ago and it's still standing strong . I also make a small charcoal grill and the insulated one cooks much better. It's amazing how much loss get radiated out the sides.
That's why the one with the coil on the inside heats faster but less efficient and uses more wood. Less draft and air is also a result. Without insulation you always will have a lot of un-burned gasses. Insulation buys you time to mix thing together.
My dad built something similar in the late 1980s with 55 gallon drums, copper coil and a therno fan used as a generator for a small water pump. It worked pretty good as long as you could keep it fed. He ended up using railroad ties as fuel and that worked very well. We always had hot water in the cottage, idk about the legality of burning railroad ties but the railroad was happy to give the ties to him. The 80s were a wonderful time.
In boilers, there is the phrase "Hot to hot, cold to cold". This refers to the optimum flow direction of water relative to combustion gasses. The coldest water should enter the stack and the hot water (or steam) should be withdrawn from a place alongside the fire. This makes sense, we can measure boiler effectiveness by exhaust gas temperature -- the cooler the exhaust, the more efficient the boiler. Obviously, cold water entering the stack will remove more heat from the gases than hot water will. The technical term is "counterflow circulation".
If you are putting cold water in at the spot furthest from the fire, and taking hot water out at the spot closest to the fire, then you are doing it right.
Yes you are correct. I am a retired steamship marine engineer. For the counter flows, you must have forced circulation. If you wish to have thermo-siphon with no pump, then the water needs to rise naturally. Simple, no electrical mechanical devices to depend upon. I made a monster one just like this out of a 4 foot tall oxygen cylinder, wrapped the coils around the bottle and then wrapped the cylinder/coil assembly in ceramic wool, then built an outside encasement with cement board. I used 50 feet of 3/4" copper tubing. It works great, although one must feed the wood (four 2" diameter pieces 18" long) every 40 minutes or so and it is tough to go outside in the rain or snow numerous times a night to keep it going. The water enters the recycled electric water heater (on 5 ft tall stilts) around 180 degrees F. All done using thermo-siphon.
@@steverturnsk6190have you considered using a sleeve of sand to act as a thermal battery around your copper coils? Once you get that heat into the sand it keeps the heat quiet well.
You earned a comment because I want to criticize: because you added another variable to the equation by adding a pump to the square stove and only using thermal cycle for the round one. To mix the water better, put the exit pipe on the thermal cycle near the bottom of the bucket to force the water to mix in the bucket. Great build!!!!! but adding unnecessary variables into the experiment makes the comparison hard to take at face value
It certainly would have been better if the only variables in the test were the coils on the inside vs the outside, but using a pump in one test when he knows it's going to skew the results makes it hard to find value from this comparison.
@@Smithcraft1 there is value, but the comparison is convoluted by the pump. If he listens to the comment, he will think about how to set up the experiment better so hopefully he will be comparing apples to apples next time
Pro tip for bending, cap at least one end of the copper tube with a valve. Solder it on, or use something like a sharkbite or compression for ease of undoing. Cap the other end with a plain cap, or another valve. Now you can fill the tube with water, under pressure, and close it without losing any. Incompressible water, already under 10s of pounds of pressure not only works better than sand or salt to prevent kinks, but it's far easier to get out. Just open your valve and remove your fittings.
I played around with this 20 years ago. By play around I mean I'm obsessed with everything I get into until there is nothing left to learn lol! Things you will discover: There is not enough surface area in your water exchanger to efficiently convert your wood fuel to heat. Cooling the combustion chamber by putting the exchanger there is actually very inefficient. You must get the max temperature in your combustion chamber before this exhaust is passed through your heat exchanger(s). Without getting into a very complex design, the simple way to get +85% effeciency is insulated combustion chamber, reburner (air injection point in higher up in the combustion chamber), deflector to seperate combustion chamber with secondary insulated chamber using inside copper pipe 25 to 50ft with deflection baffles, then send the remaining heat through an old (cleaned) aluminum heater core (from a car) and suck all this out with a fan of which you can experiment with variable voltage or a damper to adjust overall flow for best overall efficiency. You will also learn a lot about wood humidity and stack condensation, lol. Anyway, you brought back some fun memories of my early experiments many moons ago. I've only run into a few folks that like to tinker, learn, and perfect things as im driven to do (They have formed the best group of friends I have ever made). I love to see others with the same drive and interest. Keep it up and keep having fun!
@@Kammitoes heck yeah! You're welcome! But I should say, depending on who you ask this may or may not be a rocket stove.. it's a pretty loosely used name but the more you dig the more you'll learn about them and the principals that make them work.
If you add a plain loose metal sheet into the flue, it'll help with efficiency. The metal sheet/plate heats up, and radiates the energy from the gasses in the middle of the flow onto the the coils. Might not be a ton, but I've heard that gas water heaters do that to get a few more percent efficiency. Also, if you're using a pump, you might do cross-flow on the coils. Cold water into the top and warm water out of the bottom. The thermal gradient is more efficient that way. Kind of interesting - the same principle is used in some fish gills - the unoxygenated blood is fed into the last gills first, where the water has already had some of the oxygen pulled out. The result is that the fish can "breathe" a lot more efficiently and even to lower concentrations of oxygen where they might not survive otherwise.
One thing I noticed after building several wood burning water heater is when you put the copper coil inside the stove it will get charred on the outside skin of the coil in turn insulating the water from the heat enough to be frustrating as the water can escape the heat enough to stay Luke warm! When using propane burner inside with inside coil the results were much better as it doesn't accumulate the black crust when using wood!
I have built a similar setup for the kids pool in the garden. Similar tube turns, but extended over a longer tube section. Built a second jacket and filled it with aluminium grains for heat conduction and storage. Idea is to have the hot gas interact longer with the exhaust pipe to get more heat transfer out of the hot gasses to the water. The aluminium granules help transfer that heat to the copper pipe. It can start boiling in the tube, which significantly helps feeding the water through it.
Some pipe wrap on the outlet (hot) hose would help retain some of that heat. Those open hoses are acting like radiators. In fact, leave enough copper to run all the way to the storage tank, and wrap that. Honestly, I'm waiting for the video where you get the water hot enough the hose melts. Great videos man, thank you!
From the Pacific Northwest, Can't wait to have Hot water to take a shower while camping this year. My family thanks you, without any idea how hot H2O came to camp this summer!!! lol
My grandparents built two similar in the 40's. One in the fireplace chimney and one separate very similar to your one. They still work perfectly and heat most water to the shower and radiators.
My dad was my scout leader, he took a milk can, made a copper coil,, coil was placed in campfire. Exit outside the fire. Couldn't touch the water w/out adding cold water. Worked perfectly .
Homemade hot tub. Centerline Designs did one out of a black ¿fish pond liner? Or cattle watering thing. Temporary setup, one or two time use, drain water.
Great video! Yes the first one will perform faster with that pump since you're creating a recirculating pump essentially so less energy to heat up the water because the warm water is moving more through out the system faster as utilizing less energy.
Also not to mention the pipe size diameter does help with not needing as much heat time as well as the length of the pipe. I feel this experiment would be great in a fixtures class for plumbing trade schools
Been running these for years in northern mn and canada in winter to keep our ice fishing holes ice free. We used an internal coil in a folgers can fired with a couple handfuls of charcoal.
I'm so floored by this project, my man! Hail State, for one, but also I had no idea that the thermosiphon effect was a thing until I saw this project in Shorts. The square tubing specifically with the copper coil inside strikes me as a more elegant design and the one I'm more familiar with, but the round tube one really is a damn pretty thing. I'm impressed how you welded those detachable legs on, I'm gonna have to pilfer that idea for something in the future. The way you were able to dump such an extraordinary amount of heat into quite a lot of water with pretty minimal inputs, especially on a stove that could very well be used to cook food on at the same time, is absolutely spectacular. I'm beyond impressed! What a project! The '$125 worth of copper and fittings' really only counts for $12.5 since it's in a project you're making yourself anyway. Always divide materials costs by ten, but only once the project is done. 😉 Also I really want that MSU 5 gallon bucket you've got. That's steezy as all hell.
Also I'm curious if copper pipe is even all that necessary since the heat differential is so high. I'd guess that steel would probably give a similar efficiency at a lower price, but you'd probably need tools or leverage or a shitload of elbow grease to get it bent. Packing sand into the pipe before bending is a clever trick. I haven't done copper tube bending before, but I've casted copper tubes and found they're real easy to kink and fold, but not easy to bend. Neat trick.
Ive watched this video, and then i had to go back to watch the previous rocket stove build to make some comparrisons. While im no rocket stove expert, i did make some observations which might make a difference in your results. Particularly you had more variable than just square tube vs round, and inside pipe vs outside. And the inside vs outside is a huge deal just by itself. I think there are 2 major factors which caused the original square tube unit to perform better and heat up faster. The smaller diameter and length of copper and factor of the pump made it perform better. When the copper is smaller diameter, that alone will help to transfer temperature faster. Brewers will run their fresh brew wort through a copper pipe submerged in icewater to bring down the temp quickly to pitch the yeast. Although it takes longer for the water to flow through small diameter pipe, it will come out much hotter from passing through small tube. Since you used 2 different pipe sizes, 1/2" vs 3/8", the one with the 1/2" will transfer heat more slowly. Also, was the length the same? The bottom line is, how much volume of water was exposed to exchange heat between one unit or the other? Next, the square tubed stove had the extra help of a water pump to get more water through the heat exchanger more quickly. The other just used the natural flow of cold and hot water, which is nice that that factor works without a pump, but at a much slower rate. So to have a more equal test, id suggest to use the same size copper pipe on both units, either 3/8" or maybe even 1/4". And make sure the length of pipe is the same to ensure the same amount of water is exposed to the heat. And then id recommend to use the same pump rig setup for both. Also, i liked that you started off with ice water for the extreme, but id suggest to make a second test where you use more likely ambient water, maybe around 65° starting and see how that comes out. I really think reducing the copper pipe size and adding a pump will make a distinct difference where both units may perform somewhat on par with each other, although i still anticipate the square tube stove with internal tubing will be slightly faster. Thanks for this content and the great ideas you share with others. Best wishes.
I agree with all aspects of this post I was thinking on the same lines even as the test began I was of the opinion the test was not balanced (Automotive Quality Engineer and Compliance Auditor)
You're definitely a pro and like what you got going on... tip I learned in commercial plumbing is to polish all your length before yout cut... easier to polish a large piece rather than several cuts.
I've delved a bit into this for heating an outside spa. One problem I found with having the copper pipe directly over the flame is after a few times it builds up a layer of soot over the pipe with makes it harder to heat in the long run
Cool stuff. If you mess with this a lot, you can buy a combustion analyzer and make an intake that you can meter to get the burn as efficient as possible, maybe some baffles in the chimney or a cap, to slow the draft and use a small pump like you did on the square stove. I would bet you could get the ice water to 120 In half the time! Thanks for the content!
I have always wondered why people put the inlet and outlet of the bucket of a thermosiphon at different levels. You could put both at the bottom or send the hot water into the bottom of the bucket. As long as the hot water coming out of the rocket stove continues upwards it will cycle. The pressure in the whole system is the same as it acts as one column of water.
Nice Shop and cool idea for water heating. I built a Coiler 3 inch diameter pvc rod about 2 1/2 feet long _ took it to CNC Shop to cut the spiral groove to fit heavy wall copper tube. Used a winch motor -had to cut spool to use the spline. 😊 Motor directly in line with pvc Axle..have to remove the end bearing block to unscrew the copper pipe.
If you ran the test again, could you run the pump with the new stove as I think that it probably reduced the time needed to heat the water by a fair emount. I'd be really interested in the results 🤔 Thanks for another cool project 😊👍👍👍👍
Nice! You always make the best stuff. By the way; stable ice water that is completely mixed and the ice is only slowly melting, the water is at 32°F (0°C) with only adjustments for how far your pressure altitude is away from standard sea level pressure of 29.92" Hg. Any remaining ice that remains in the bucket is negative thermal mass that has to be heated. You should have added ice to each bucket, let it stabilize and then remove all the ice, and had the same volume/weight of water, and it would have been at the same temperature and thermal mass for adding heat energy. Good test otherwise.
I'm so glad to find this video to test which is more efficient. I knew the square one with a built-in coil inside would heat up faster. That was my first initial guess before you started the stoves. I would pass it on to my friends who want to heat up the outdoor tub. This would do it! Thanks!
Love to see this kind of ingenuity, I use this same principle in refrigerant recovery. A 1/2” copper coil covered w/3/4” clear tubing submerged into a 5 gallon bucket of water, 3/4” tube attached to a submersible pump (pump circulates water through clear tubing over copper tubing) the other end near the top of bucket. Copper line used as refrigerant in/out. For faster recovery fill bucket w/ice. Refrigerant likes to migrate to the coldest area, by circulating cold water over the copper tubing, thus rejecting heat to the ice water you have created a condenser, and can quickly move refrigerant.
Can also wrap the copper tubing around a section of pipe a hair smaller than the pipe in your finished rocket stove. The copper will then have a tighter fit around your permanent stove.
Great little water heaters, definitely worth the money, seem to be working great ether one, thanks for sharing, all the best to you and your loved ones
Awesome build, here are some suggestions for a version 3.0: - smaller copper pipe diameter, but a way longer pipe, may help with faster heating, since smaller volume of water inside per surface area of coil touching the stove wall. Ideally the copper would be wound all the way up the chimney, to maximize surface contact and therefore heat exchange. In a theoretical perfectly efficient system, this would mean that the stove exhaust gases and the water exiting the coil would be at the same temperature. - Some kind of heat transfer substance (similar to thermal paste between computer chips and heat sinks) between the copper coil and the stove wall would be great, since the contact of the round tubing on the flat wall is basically minimized by the geometry of the round tube (only tangentially touching). Building an additional outer wall around the copper tubing and filling it up with fine sand (or maybe even filling it with lead?) should work. This will increase warm-up time for the stove itself, because it's just more mass to heat up, but should increase overall efficiency. - square copper tubing may also work, since it would increase contact surface with the stove wall.
Disadvantage of smaller diam tube: if water is V 'hard' it will after many ? hrs, bung up with lime-scale . Insulating filling of lead - No-No : will melt (too-heavy anyhow)😮
Woops! I'm pretty sure this comment was meant for another video I was watching before this one. The autoplay musta kicked in before I sent this comment on the previous vid. Sorry it doesn't make any sense here.
now if you put the tube inside the rocket stove you have a water tube boiler aka a steam generator, they used them in steam powered cars, experimental high-pressure steam locomotives (that tended to hit above 300 PSI!), and most commonly in power plants and for WWII-era steamships
Thank you for this video. We have an old soviet summer house which was never built to be centrally heated nor with hot water. This low tech solution is great as there is loads of wood for free.
Great way to use water as a thermal ballast. I like having the copper tubing inside the flue, whether the flue is round or square. Inside would have to have a better heat transfer. We had a wood burner in our basement (NE Ohio) when I grew up and my dad kept a cast iron pot full of water on the stove. It helped add some moisture to the air in the house which was very dry because the fire was going almost every night in winter.
Pro tip when unraveling your coil place one end on the ground preferably flat and clean of debria and put your foot on it. Applying downward force roll it out on the floor and continually keep your foot a few feet at most from the roll. Its 10x easier to roll out fairly straight and almost never kinks your coil.
Ferrule not feral my friend. It's a good idea for you to be doing this and to have made this video because if the grid collapses we have to have clean water but having hot water to wash things and to bathe with it's almost a necessity in itself
Boy, that's a humdinger of a stove! Really nice to build, if you have the tools and skill-set. Getting someone to make that for me is going to be prohibitively expensive. Worth mentioning- on bending the copper pipe, get a wooden fence post the same diameter of the stove. Drill a hole through to run part of the pipe, to anchor it. Then instead of wrestling with the pipe, you wrestle with the post, which is far easier (I think).
Estimado Patrick, gracias por enseñar y compartir tus experiencias. Yo no soy experto , pero hace años que vengo experimentando sosas por el estilo. Yo creería, como en toda experimentación basal ciertas condiciones deben ser iguales para los dos tipos de estufas, por ejemplo, que los dos baldes de agua, deberian estar a la misma altura. La presión hidrostática y otros factores No serian iguales para ambos tipos de estufas en tu video . Igual longitud, diámetro de manguera, igual altura y cantidad de líquido y leña pesada en una balanza. ¡ Tenlo en cuenta ! y anota o filma los registros comparativos , como lo has hecho. Te deseo éxito en tus experimentos, te Felicito . Salud para tí y los tuyos. Un gran saludo desde Córdoba, Argentina !
You should also try the new pipe model using the pump just for a fairer comparison, since faster circulation could mean quicker temp increase (possibly more efficient), so might find along with the change in venting the contest could be a lot closer.
The difference in fuel consumption and temp was because the square stove got ventilation from the bottom tube the entire time, while your new stove only got ventilation towards the end, which is why it burned hotter, I would think. really cool video!
Seriously I'd weld the two smaller pieces first and grind, but nice first welds there. I'd prefer slow and steady with less fuel used overall so round would be the go for me, maybe coils inside like the square since they'd coil up nice and snuggly inside. You'd have to cut a slot near the base to pull up the pipe unless you were a magician with tools to grab the end out of a hole, but a slot would suffice, it may even be a good small permanent vent if you didn't weld back in a piece. Great video, I also like old huge gas cylinders.... ;)
twenty years ago I made a swimming pool heater with a similar principle. But i use propane gas burner. The copper used is very long and goes into ten 4 inch pipes and bellow those pipes there is one gas burner for the ten pipes. The pipe is insulated with ceramic wool and the outside, the outer cover is 70 cm in diameter (± 27 inches) What I want to share is that the pipe should not be filled with sand when it is rolled, because a pipe that become flatened when rolled turns out to spread the heat better, because the heat spreads more quickly to the middle of the pipe. at least 10-15 percent heat faster. I also use solar energy for preheating, so gas usage is 20 percent more economical. The heating project was one of the most successful ones I worked on. To heat a 25 meter x 15 meter swimming pool, only use 3 such heating units. the temperature reached can reach 34 degrees Celsius or around 93 Fahrenheit.!!
How long did it take to get the pool water that warm though. And the expense. That was what my dad complained about when we had an indoor swimming pool was how expensive it was to keep it heated especially in the winter. Ran it on propane. But I sure enjoyed it. But how did you flatten the pipe?
A couple of observations I'd like to offer: The square tubing one has a shorter flue than the cylinder one, so it wasn't an exact comparison. Also, you would have a more efficient burn if you had a longer flue, and the copper on the upper part of the flue. I think the reason that you were getting an inefficient burn (as seen from the smoke) was because the temperature of the burn chamber was being cooled down with water. You could also try introducing secondary air, but that's a separate experiment
too many coils in too tight of a space, cools off the chimney and creates and erratic smokey burn. the chimney needs to be about 3 times what it is to function. anyone that took physics should remember that heating water doesn't happen fast and a rocket stove is just a fuel hungry, wasteful excuse for a heat source. unless you're trying to get rid of a lot of wood fast. it only takes three complete wraps spiraling up to allow smoke to spiral past any cold spot created and allow the heated water to rise as fast as possible. the other issue with too many coils is the excessive resistance created internal can split the tubing, steam burning anyone near it.
That's exactly what I thought. First thing - round flutes. Good burn and draft requires a round chinmey to minimise vortexes. Second thing - temperature in the burn chamber must be high. Really high to burn completly. That's why a lot of such constructions have that part insulated. Third thing - "afterburner" - additional air intake where gasses are burnt. Especially heated air, where air ducts take heat from the flute and make the burn much more efficient. And then, you can start draining energy from burned gasses. Basically you put coils where there is no flame.
@@kimjune That's ok if you add oxygen to afterburn gasses. Not much ok if you just want to expell gasses after burn. Then you want that exhaust as smooth as possible.
Excelentes propuestas, la que representó más trabajo en la elaboración es más eficiente, seguramente porque el espiral de cobre recibe directamente el fuego. Saldos desde México 👍👋🏾👋🏾👋🏾
Nice looking stove!Slice a scrap piece of the pipe lenghtwise and weld it so it's slightly smaller in diameter then use it to wrap the copper so it will be tight on the stove.
The first stove has roughly twice the air intake. And an electric pump. It runs lean and has electric assistance. It's awesome. I like the other slow burning stove that doesn't need any outside help. I see you opened the bottom vent, and it worked better. I want to see a rematch.
What a guy !! Climb that roof,fill that pipe 😊 my kind of guy 😊. Love ya man ... Always remember bro, the player haters will Always Criticise... 🙏🏻🏴
Honestly, good on you for not taking the freezing the pipe idea. It just sounds like a bad idea considering water expands when turned into ice meaning it would risk destroying the pipe. Also using salt or something that would dissolve in water in theory makes sense, but then you consider that you're using dry sand in a pipe with relatively gentle bends. Just use compressed air afterwards to blow the sand out then use some water to make sure any extra dust left behind is rinsed out.
Should sleeve the outside with steel and fill it with sand instead of exhaust wrap. Sand is great and holding and distributing heat. Also the compression fittings need to be lubed with Vaseline to really work correctly.
Love the design, i would love to see a very portable version of this. Perhaps in the future I will experiment with a back packing collapsible rocket stove with the coil inside. But if you beat me too it I would thoroughly enjoy that video. Cool work!
That's the smartest looking design I've seen extent!!!! Outstanding young🌱 man 👏!!!!! Mine heat's a 150 gallon hot 🥵 tub in an hour maybe 70 minutes except a little taller and it's a six inch diameter version but one could easily say the look like twins!!!! No pump nessesary water 💧💦 in at the bottom and the heat rise's it up in the top!!!!
For the thermo-syphon, its best to leave the return hose above the water surface. This allows for much easier one-way flow. For the pumped system, water should enter at the top if the coil and exit the bittom. This makes for more efficient heat transfer, as the temperature differential is higher. Having the coil in the exhaust flue is going to.extract much more heat, as the exhaust gasses will contact the entire surgace are of the coil.
Pump works best because heat conduction is best when temperature difference is greatest and pump ensures this difference by replacing hot with cold quickly. Nice build.
Great work man! Next time you run a test, either have a pump to cycle water for both or neither. I believe that having that pump cycle the water helped to heat it up faster.
Thanks for showing us your hard work, I really appreciate it😁 Making things really teaches you through experience. People can criticise all they want, but do they show you what they make? 😉👍
I’m sure there are already tons of comments but if your pumping one through the heat exchanger and the other relying on thermal flow , the pumped one will work way better and because it’s using absorbing more heat faster you’ll have to feed it more. Cool video though.
Firstly, props for building these. Do they smoke? I wonder if you slid the copper coil up the chimney some you might actually get more energy out. Could be that cooling the combustion chamber would reduce combustion efficiency. I'd be interested if that changes the power output, up or down.
Thay second unit with the pipes on the outside I believe is the safer and better option. My brother is a plumber and lived off grid for a while and made something similar. When I asked if he would get more heat from the copper being in the flames, I recall he said something about its not good, as direct heat makes copper emit something. I can't remember what. He had his pipes on the outnaide with another layer of metal wrapped around that, likenyou have the thermal tape. Also, look up convection and conduction, as these two bits of science may also help you get the transfer of heat sooner (I'm a firefighter).
The first iteration had greater surface area of piping in contact with greater temperature air. Its not a surprise it operated better. The inlet crossectional area will be directly correlated with air intake as a ratio to fuel blocking airflow. Of course the first will eat fuel more its got a larger air intake to stoikiometrically mix with fuel. Try a tighter coil that sits proud of the internal wall. You could also double heat by having tube within a tube venting exhaust through inside and water between pipes.or pre-heating externally, then heating internally. I wonder if a dule offset inlet generating a spiral airflow might also generate additional heat. Whether that would work as a heater idk. Fun to design
11:20 best quote I've heard on TH-cam this year. That or 'don't do anything dum, dangerous or different'. Extra points if you know. Subbed 🤙 Edit, kudos on finding out the olive terminology 👍
It would’ve been way better if you just made it like this instead of that. Next time try changing that piece to this piece and it’ll be much better, trust me
😂😂😂 right! I knew I should have changed that piece.
@@PatrickRemington The trust me part was absolutely necessary lol glad you realize your mistakes now though ✅😂😂
Glad someone said it ! Haha
Yeah, thingy is definitely better than thangy! 🤪
How did u become human again though ?
The round one used less wood and didn’t use a pump. One could argue that it was most efficient.
As with most things in engineering, usually maximizing efficiency in one variable decreases efficiency in another. In this case, fuel efficiency vs. time efficiency.
I liked the round one best too. (Maybe I'm biased though because I'm better at welding round tube, and I'm planning on making a RMH.)
thermally speaking,if the tube surface used where to be the same, the square one would be better because the tube is directly exposed to the heat making it easier for the heat to exchange between the water and the heated air.Whilst the round one, only part of the tube surface is in contact with the metal so the heat has to transfer from the heated air to the metal,conduct the heat through the metal and finally jump from te metal to the copper. Trapping the hot air around the tube with the insultaing tape helps on the efciency but the square one is defintely the winner here.
also the square stove has a way bigger gap for the air to flow in,making it more eficient in burning fuel. Thats why it runs so fast out of wood. Although we could argue if that's beneficial for the exchange of heat. Maybe limiting the opening on the air gap to slow down the combustion would make it better.
That's what I said. Pump is circulating and mixing the water in the bucket. Goes so far as weighing the wood to be equal then uses a pump in one and not the other.
I had started getting much better results with my rocket stoves after surrounding them with galvanized half inch mesh wire double layer and then making my own refractory concrete mix with perlite which is insulative. The results are insane. The stack is super insulative which makes the internal combustion much easier and more ferocious and more efficient
I've never used perlite.i use vermiculite. 5 to one ratio with cement and a bit of sand.
I made a pizza oven 7 years ago and it's still standing strong .
I also make a small charcoal grill and the insulated one cooks much better.
It's amazing how much loss get radiated out the sides.
That's why the one with the coil on the inside heats faster but less efficient and uses more wood. Less draft and air is also a result.
Without insulation you always will have a lot of un-burned gasses. Insulation buys you time to mix thing together.
My dad built something similar in the late 1980s with 55 gallon drums, copper coil and a therno fan used as a generator for a small water pump. It worked pretty good as long as you could keep it fed. He ended up using railroad ties as fuel and that worked very well. We always had hot water in the cottage, idk about the legality of burning railroad ties but the railroad was happy to give the ties to him. The 80s were a wonderful time.
Not so much the legality so much as breathing in any of the fumes coming off of them, damn
In boilers, there is the phrase "Hot to hot, cold to cold". This refers to the optimum flow direction of water relative to combustion gasses. The coldest water should enter the stack and the hot water (or steam) should be withdrawn from a place alongside the fire. This makes sense, we can measure boiler effectiveness by exhaust gas temperature -- the cooler the exhaust, the more efficient the boiler. Obviously, cold water entering the stack will remove more heat from the gases than hot water will. The technical term is "counterflow circulation".
Soo you’re saying I’m doing it right or no?
If you are putting cold water in at the spot furthest from the fire, and taking hot water out at the spot closest to the fire, then you are doing it right.
Yes you are correct. I am a retired steamship marine engineer. For the counter flows, you must have forced circulation. If you wish to have thermo-siphon with no pump, then the water needs to rise naturally. Simple, no electrical mechanical devices to depend upon. I made a monster one just like this out of a 4 foot tall oxygen cylinder, wrapped the coils around the bottle and then wrapped the cylinder/coil assembly in ceramic wool, then built an outside encasement with cement board. I used 50 feet of 3/4" copper tubing. It works great, although one must feed the wood (four 2" diameter pieces 18" long) every 40 minutes or so and it is tough to go outside in the rain or snow numerous times a night to keep it going. The water enters the recycled electric water heater (on 5 ft tall stilts) around 180 degrees F. All done using thermo-siphon.
@@steverturnsk6190have you considered using a sleeve of sand to act as a thermal battery around your copper coils? Once you get that heat into the sand it keeps the heat quiet well.
@@steverturnsk6190could simply extend the hopper and add chips or something that will progressively burn down with the long sticks
+1 for weighing the wood for the test.
I understand as a content creator. Comments, likes shares. And full views.
You earned a comment because I want to criticize: because you added another variable to the equation by adding a pump to the square stove and only using thermal cycle for the round one. To mix the water better, put the exit pipe on the thermal cycle near the bottom of the bucket to force the water to mix in the bucket. Great build!!!!! but adding unnecessary variables into the experiment makes the comparison hard to take at face value
It certainly would have been better if the only variables in the test were the coils on the inside vs the outside, but using a pump in one test when he knows it's going to skew the results makes it hard to find value from this comparison.
@@Smithcraft1 there is value, but the comparison is convoluted by the pump. If he listens to the comment, he will think about how to set up the experiment better so hopefully he will be comparing apples to apples next time
Isn’t he comparing one STOVE to ANOTHER? That makes it apples to apples it seems.
@@Meme-qd2oj it would be except for one stove he uses a pump and for the other stove he doesn't
@@Wise4HarvestTime ok thanks! 😃
I was a pipe welder and an insulator. Wrap that in a removable blanket. It will be way more efficient
Did you weld those legs on…or was that Stevie Wonder? 🤔😬
@@jimdarhower4945 no it was your mama Helen Keller
I came here to say the same thing re: insulating blanket
@@CedarGroveOrganicFarm 🌱🌞
@ Wigington24 - ohhhh snap you got my ass good!!! You ever hear a good Hellen Keller joke?
Pro tip for bending, cap at least one end of the copper tube with a valve. Solder it on, or use something like a sharkbite or compression for ease of undoing. Cap the other end with a plain cap, or another valve. Now you can fill the tube with water, under pressure, and close it without losing any. Incompressible water, already under 10s of pounds of pressure not only works better than sand or salt to prevent kinks, but it's far easier to get out. Just open your valve and remove your fittings.
Could sharkbite take the heat that could get up to ?
@ladybugsarah6671 i think he is saying its only used for the bending process.
I played around with this 20 years ago. By play around I mean I'm obsessed with everything I get into until there is nothing left to learn lol! Things you will discover: There is not enough surface area in your water exchanger to efficiently convert your wood fuel to heat. Cooling the combustion chamber by putting the exchanger there is actually very inefficient. You must get the max temperature in your combustion chamber before this exhaust is passed through your heat exchanger(s). Without getting into a very complex design, the simple way to get +85% effeciency is insulated combustion chamber, reburner (air injection point in higher up in the combustion chamber), deflector to seperate combustion chamber with secondary insulated chamber using inside copper pipe 25 to 50ft with deflection baffles, then send the remaining heat through an old (cleaned) aluminum heater core (from a car) and suck all this out with a fan of which you can experiment with variable voltage or a damper to adjust overall flow for best overall efficiency. You will also learn a lot about wood humidity and stack condensation, lol. Anyway, you brought back some fun memories of my early experiments many moons ago. I've only run into a few folks that like to tinker, learn, and perfect things as im driven to do (They have formed the best group of friends I have ever made). I love to see others with the same drive and interest. Keep it up and keep having fun!
"He's strong... and blows good" You got the job
I never even knew what a Rocket Stove was until I watched this. Now I want to make one. Thanks
@@Kammitoes heck yeah! You're welcome! But I should say, depending on who you ask this may or may not be a rocket stove.. it's a pretty loosely used name but the more you dig the more you'll learn about them and the principals that make them work.
If you add a plain loose metal sheet into the flue, it'll help with efficiency. The metal sheet/plate heats up, and radiates the energy from the gasses in the middle of the flow onto the the coils. Might not be a ton, but I've heard that gas water heaters do that to get a few more percent efficiency. Also, if you're using a pump, you might do cross-flow on the coils. Cold water into the top and warm water out of the bottom. The thermal gradient is more efficient that way. Kind of interesting - the same principle is used in some fish gills - the unoxygenated blood is fed into the last gills first, where the water has already had some of the oxygen pulled out. The result is that the fish can "breathe" a lot more efficiently and even to lower concentrations of oxygen where they might not survive otherwise.
One thing I noticed after building several wood burning water heater is when you put the copper coil inside the stove it will get charred on the outside skin of the coil in turn insulating the water from the heat enough to be frustrating as the water can escape the heat enough to stay Luke warm! When using propane burner inside with inside coil the results were much better as it doesn't accumulate the black crust when using wood!
I am absolutely in love with engineering on the fly! I just learned something new today!
Nice builds!! I probably would have used a pump on both to get a fair comparison. great for a small hot tub or clawfoot bathtub with a view!
I have built a similar setup for the kids pool in the garden. Similar tube turns, but extended over a longer tube section. Built a second jacket and filled it with aluminium grains for heat conduction and storage.
Idea is to have the hot gas interact longer with the exhaust pipe to get more heat transfer out of the hot gasses to the water. The aluminium granules help transfer that heat to the copper pipe. It can start boiling in the tube, which significantly helps feeding the water through it.
Some pipe wrap on the outlet (hot) hose would help retain some of that heat. Those open hoses are acting like radiators. In fact, leave enough copper to run all the way to the storage tank, and wrap that. Honestly, I'm waiting for the video where you get the water hot enough the hose melts. Great videos man, thank you!
From the Pacific Northwest, Can't wait to have Hot water to take a shower while camping this year. My family thanks you, without any idea how hot H2O came to camp this summer!!! lol
My grandparents built two similar in the 40's. One in the fireplace chimney and one separate very similar to your one. They still work perfectly and heat most water to the shower and radiators.
Patrick just nonchalantly called us all weak 😂
RIGHT!😂😂😂💥
Deadass
And then he says how heavy the tubing is filled with sand. Where did the strength go ?
“ I am very strong not sure if you’ll be able to do this” as if he’s talking to a bunch of women😂😂😂😂
In my case calling me weak he is right!
Really enjoyed this. Thanks for being so real about your abilities. I’ve been Tig welding for 20 years, and I’m intimated by MiG Welding.
I would DEFINITELY have shoved the hose from my air compressor into the pipe to clear the sand XD That sounds like fun lol. Such a cool project!
My dad was my scout leader, he took a milk can, made a copper coil,, coil was placed in campfire. Exit outside the fire. Couldn't touch the water w/out adding cold water. Worked perfectly .
I’ve seen a number of rocket stoves come out in the last few years and my biggest thought has been application. Appreciate the idea.
Homemade hot tub. Centerline Designs did one out of a black ¿fish pond liner? Or cattle watering thing. Temporary setup, one or two time use, drain water.
Great video! Yes the first one will perform faster with that pump since you're creating a recirculating pump essentially so less energy to heat up the water because the warm water is moving more through out the system faster as utilizing less energy.
Also not to mention the pipe size diameter does help with not needing as much heat time as well as the length of the pipe. I feel this experiment would be great in a fixtures class for plumbing trade schools
Been running these for years in northern mn and canada in winter to keep our ice fishing holes ice free. We used an internal coil in a folgers can fired with a couple handfuls of charcoal.
... a pot of water over a fire... 1000 year old tech, still the best. "A watched pot never boils"
Yeah, for sure :)
I'm so floored by this project, my man! Hail State, for one, but also I had no idea that the thermosiphon effect was a thing until I saw this project in Shorts.
The square tubing specifically with the copper coil inside strikes me as a more elegant design and the one I'm more familiar with, but the round tube one really is a damn pretty thing. I'm impressed how you welded those detachable legs on, I'm gonna have to pilfer that idea for something in the future.
The way you were able to dump such an extraordinary amount of heat into quite a lot of water with pretty minimal inputs, especially on a stove that could very well be used to cook food on at the same time, is absolutely spectacular. I'm beyond impressed! What a project!
The '$125 worth of copper and fittings' really only counts for $12.5 since it's in a project you're making yourself anyway. Always divide materials costs by ten, but only once the project is done. 😉
Also I really want that MSU 5 gallon bucket you've got. That's steezy as all hell.
Also I'm curious if copper pipe is even all that necessary since the heat differential is so high. I'd guess that steel would probably give a similar efficiency at a lower price, but you'd probably need tools or leverage or a shitload of elbow grease to get it bent.
Packing sand into the pipe before bending is a clever trick. I haven't done copper tube bending before, but I've casted copper tubes and found they're real easy to kink and fold, but not easy to bend. Neat trick.
10:18 drill a hole through the thick part of a 2x4 and pull the tube through. Perfectly straight very fast work
That is a very good idea!
Ive watched this video, and then i had to go back to watch the previous rocket stove build to make some comparrisons. While im no rocket stove expert, i did make some observations which might make a difference in your results. Particularly you had more variable than just square tube vs round, and inside pipe vs outside. And the inside vs outside is a huge deal just by itself.
I think there are 2 major factors which caused the original square tube unit to perform better and heat up faster. The smaller diameter and length of copper and factor of the pump made it perform better. When the copper is smaller diameter, that alone will help to transfer temperature faster. Brewers will run their fresh brew wort through a copper pipe submerged in icewater to bring down the temp quickly to pitch the yeast. Although it takes longer for the water to flow through small diameter pipe, it will come out much hotter from passing through small tube. Since you used 2 different pipe sizes, 1/2" vs 3/8", the one with the 1/2" will transfer heat more slowly. Also, was the length the same? The bottom line is, how much volume of water was exposed to exchange heat between one unit or the other?
Next, the square tubed stove had the extra help of a water pump to get more water through the heat exchanger more quickly. The other just used the natural flow of cold and hot water, which is nice that that factor works without a pump, but at a much slower rate.
So to have a more equal test, id suggest to use the same size copper pipe on both units, either 3/8" or maybe even 1/4". And make sure the length of pipe is the same to ensure the same amount of water is exposed to the heat.
And then id recommend to use the same pump rig setup for both.
Also, i liked that you started off with ice water for the extreme, but id suggest to make a second test where you use more likely ambient water, maybe around 65° starting and see how that comes out.
I really think reducing the copper pipe size and adding a pump will make a distinct difference where both units may perform somewhat on par with each other, although i still anticipate the square tube stove with internal tubing will be slightly faster.
Thanks for this content and the great ideas you share with others. Best wishes.
I agree with all aspects of this post I was thinking on the same lines even as the test began I was of the opinion the test was not balanced (Automotive Quality Engineer and Compliance Auditor)
I love rocket stoves and this is BEAUTIFUL. What a fabulous way to start a day!! 👍🇨🇦
You're definitely a pro and like what you got going on... tip I learned in commercial plumbing is to polish all your length before yout cut... easier to polish a large piece rather than several cuts.
I've delved a bit into this for heating an outside spa. One problem I found with having the copper pipe directly over the flame is after a few times it builds up a layer of soot over the pipe with makes it harder to heat in the long run
I made an off-grid shower and use a big ol' laundry pot that I just stoke a fire underneath. That works great, 40l of boiling water in just 20mins.
Cool stuff. If you mess with this a lot, you can buy a combustion analyzer and make an intake that you can meter to get the burn as efficient as possible, maybe some baffles in the chimney or a cap, to slow the draft and use a small pump like you did on the square stove. I would bet you could get the ice water to 120 In half the time! Thanks for the content!
I have always wondered why people put the inlet and outlet of the bucket of a thermosiphon at different levels. You could put both at the bottom or send the hot water into the bottom of the bucket. As long as the hot water coming out of the rocket stove continues upwards it will cycle. The pressure in the whole system is the same as it acts as one column of water.
Nice Shop and cool idea for water heating. I built a Coiler 3 inch diameter pvc rod about 2 1/2 feet long _ took it to CNC Shop to cut the spiral groove to fit heavy wall copper tube. Used a winch motor -had to cut spool to use the spline. 😊
Motor directly in line with pvc Axle..have to remove the end bearing block to unscrew the copper pipe.
If you ran the test again, could you run the pump with the new stove as I think that it probably reduced the time needed to heat the water by a fair emount. I'd be really interested in the results 🤔 Thanks for another cool project 😊👍👍👍👍
Nice! You always make the best stuff.
By the way; stable ice water that is completely mixed and the ice is only slowly melting, the water is at 32°F (0°C) with only adjustments for how far your pressure altitude is away from standard sea level pressure of 29.92" Hg. Any remaining ice that remains in the bucket is negative thermal mass that has to be heated. You should have added ice to each bucket, let it stabilize and then remove all the ice, and had the same volume/weight of water, and it would have been at the same temperature and thermal mass for adding heat energy.
Good test otherwise.
Oh man.. I don’t think we are on the same level 😂😂 but I’m willing to learn! Thanks for the info!
I'm so glad to find this video to test which is more efficient. I knew the square one with a built-in coil inside would heat up faster. That was my first initial guess before you started the stoves. I would pass it on to my friends who want to heat up the outdoor tub. This would do it! Thanks!
The square one is definitely more efficient but not just because of the direct heat also because smaller diameter copper pipe
I am sure the pump on that one would make a big difference in heat up time.
Love to see this kind of ingenuity, I use this same principle in refrigerant recovery. A 1/2” copper coil covered w/3/4” clear tubing submerged into a 5 gallon bucket of water, 3/4” tube attached to a submersible pump (pump circulates water through clear tubing over copper tubing) the other end near the top of bucket. Copper line used as refrigerant in/out. For faster recovery fill bucket w/ice. Refrigerant likes to migrate to the coldest area, by circulating cold water over the copper tubing, thus rejecting heat to the ice water you have created a condenser, and can quickly move refrigerant.
Can also wrap the copper tubing around a section of pipe a hair smaller than the pipe in your finished rocket stove. The copper will then have a tighter fit around your permanent stove.
Great little water heaters, definitely worth the money, seem to be working great ether one, thanks for sharing, all the best to you and your loved ones
Awesome build, here are some suggestions for a version 3.0:
- smaller copper pipe diameter, but a way longer pipe, may help with faster heating, since smaller volume of water inside per surface area of coil touching the stove wall. Ideally the copper would be wound all the way up the chimney, to maximize surface contact and therefore heat exchange. In a theoretical perfectly efficient system, this would mean that the stove exhaust gases and the water exiting the coil would be at the same temperature.
- Some kind of heat transfer substance (similar to thermal paste between computer chips and heat sinks) between the copper coil and the stove wall would be great, since the contact of the round tubing on the flat wall is basically minimized by the geometry of the round tube (only tangentially touching). Building an additional outer wall around the copper tubing and filling it up with fine sand (or maybe even filling it with lead?) should work. This will increase warm-up time for the stove itself, because it's just more mass to heat up, but should increase overall efficiency.
- square copper tubing may also work, since it would increase contact surface with the stove wall.
Disadvantage of smaller diam tube: if water is V 'hard' it will after many ? hrs, bung up with lime-scale . Insulating filling of lead - No-No : will melt (too-heavy anyhow)😮
I wonder if you could use stainless steel tubing and cast aluminum instead for the sleeve.
Your one blissing out at around 2:58. Brought back some wonderful feelings and memories!
Woops! I'm pretty sure this comment was meant for another video I was watching before this one. The autoplay musta kicked in before I sent this comment on the previous vid. Sorry it doesn't make any sense here.
now if you put the tube inside the rocket stove you have a water tube boiler aka a steam generator, they used them in steam powered cars, experimental high-pressure steam locomotives (that tended to hit above 300 PSI!), and most commonly in power plants and for WWII-era steamships
Thank you for this video. We have an old soviet summer house which was never built to be centrally heated nor with hot water. This low tech solution is great as there is loads of wood for free.
Too many inconsistancies and changed variables in your test. One has a lid, one has a pump, one is a siphen.
Great way to use water as a thermal ballast. I like having the copper tubing inside the flue, whether the flue is round or square. Inside would have to have a better heat transfer.
We had a wood burner in our basement (NE Ohio) when I grew up and my dad kept a cast iron pot full of water on the stove. It helped add some moisture to the air in the house which was very dry because the fire was going almost every night in winter.
You have convinced me to buy a welder.
Yes!!
Excellent workmanship , simplicity of design, and 100% on functionality in off-the-grid living.
Pro tip when unraveling your coil place one end on the ground preferably flat and clean of debria and put your foot on it. Applying downward force roll it out on the floor and continually keep your foot a few feet at most from the roll. Its 10x easier to roll out fairly straight and almost never kinks your coil.
"I am very strong" lol calm down Pat. Good build.
Great job on the video. I'll have to get a friend to weld mine up up. These will be so useful during the zombie apocalypse
Ferrule not feral my friend. It's a good idea for you to be doing this and to have made this video because if the grid collapses we have to have clean water but having hot water to wash things and to bathe with it's almost a necessity in itself
Boy, that's a humdinger of a stove! Really nice to build, if you have the tools and skill-set. Getting someone to make that for me is going to be prohibitively expensive. Worth mentioning- on bending the copper pipe, get a wooden fence post the same diameter of the stove. Drill a hole through to run part of the pipe, to anchor it. Then instead of wrestling with the pipe, you wrestle with the post, which is far easier (I think).
wow, first american to say soldering instead of the generic sawdering, worthy of me subscribing
We I’m glad you weren’t here when i kept saying aluminum excrusion the entire video instead of extrusion. Got roasted for that one 😂
@@PatrickRemington aluMINIum
Estimado Patrick, gracias por enseñar y compartir tus experiencias. Yo no soy experto , pero hace años que vengo experimentando sosas por el estilo. Yo creería, como en toda experimentación basal ciertas condiciones deben ser iguales para los dos tipos de estufas, por ejemplo, que los dos baldes de agua, deberian estar a la misma altura. La presión hidrostática y otros factores No serian iguales para ambos tipos de estufas en tu video . Igual longitud, diámetro de manguera, igual altura y cantidad de líquido y leña pesada en una balanza. ¡ Tenlo en cuenta ! y anota o filma los registros comparativos , como lo has hecho. Te deseo éxito en tus experimentos, te Felicito .
Salud para tí y los tuyos. Un gran saludo desde Córdoba, Argentina !
You should also try the new pipe model using the pump just for a fairer comparison, since faster circulation could mean quicker temp increase (possibly more efficient), so might find along with the change in venting the contest could be a lot closer.
I can confirm. This is working. Been messing around with it around 4 months ago. Managed to warm up the water by 60C.
Prettiest rocket stove, them there are fighting words 👍
The difference in fuel consumption and temp was because the square stove got ventilation from the bottom tube the entire time, while your new stove only got ventilation towards the end, which is why it burned hotter, I would think.
really cool video!
Seriously I'd weld the two smaller pieces first and grind, but nice first welds there. I'd prefer slow and steady with less fuel used overall so round would be the go for me, maybe coils inside like the square since they'd coil up nice and snuggly inside. You'd have to cut a slot near the base to pull up the pipe unless you were a magician with tools to grab the end out of a hole, but a slot would suffice, it may even be a good small permanent vent if you didn't weld back in a piece. Great video, I also like old huge gas cylinders.... ;)
twenty years ago I made a swimming pool heater with a similar principle. But i use propane gas burner.
The copper used is very long and goes into ten 4 inch pipes and bellow those pipes there is one gas burner for the ten pipes. The pipe is insulated with ceramic wool and the outside, the outer cover is 70 cm in diameter (± 27 inches) What I want to share is that the pipe should not be filled with sand when it is rolled, because a pipe that become flatened when rolled turns out to spread the heat better, because the heat spreads more quickly to the middle of the pipe. at least 10-15 percent heat faster. I also use solar energy for preheating, so gas usage is 20 percent more economical. The heating project was one of the most successful ones I worked on. To heat a 25 meter x 15 meter swimming pool, only use 3 such heating units. the temperature reached can reach 34 degrees Celsius or around 93 Fahrenheit.!!
How long did it take to get the pool water that warm though. And the expense. That was what my dad complained about when we had an indoor swimming pool was how expensive it was to keep it heated especially in the winter. Ran it on propane. But I sure enjoyed it.
But how did you flatten the pipe?
i love big magnets for welding pipe on a table
"I'm really strong" Internet arm wrestle challenge if i ever heard one. 😅
Awesome video, I'll be using this for my outdoor shower! Cheers!
A couple of observations I'd like to offer: The square tubing one has a shorter flue than the cylinder one, so it wasn't an exact comparison. Also, you would have a more efficient burn if you had a longer flue, and the copper on the upper part of the flue. I think the reason that you were getting an inefficient burn (as seen from the smoke) was because the temperature of the burn chamber was being cooled down with water. You could also try introducing secondary air, but that's a separate experiment
too many coils in too tight of a space, cools off the chimney and creates and erratic smokey burn. the chimney needs to be about 3 times what it is to function. anyone that took physics should remember that heating water doesn't happen fast and a rocket stove is just a fuel hungry, wasteful excuse for a heat source. unless you're trying to get rid of a lot of wood fast. it only takes three complete wraps spiraling up to allow smoke to spiral past any cold spot created and allow the heated water to rise as fast as possible. the other issue with too many coils is the excessive resistance created internal can split the tubing, steam burning anyone near it.
That's exactly what I thought. First thing - round flutes. Good burn and draft requires a round chinmey to minimise vortexes. Second thing - temperature in the burn chamber must be high. Really high to burn completly. That's why a lot of such constructions have that part insulated. Third thing - "afterburner" - additional air intake where gasses are burnt. Especially heated air, where air ducts take heat from the flute and make the burn much more efficient. And then, you can start draining energy from burned gasses. Basically you put coils where there is no flame.
@@astrobreaux I am needing to heat water the most efficient way, so you're saying only three wraps of the water coil?
@@ogi22 some rocket stove designs purposely build in fins to induce vortexes for a better air fuel mixture.
@@kimjune That's ok if you add oxygen to afterburn gasses. Not much ok if you just want to expell gasses after burn. Then you want that exhaust as smooth as possible.
Excelentes propuestas, la que representó más trabajo en la elaboración es más eficiente, seguramente porque el espiral de cobre recibe directamente el fuego. Saldos desde México 👍👋🏾👋🏾👋🏾
Now try in addition to put the water in a big pot on top of the stove.
Nice looking stove!Slice a scrap piece of the pipe lenghtwise and weld it so it's slightly smaller in diameter then use it to wrap the copper so it will be tight on the stove.
The first stove has roughly twice the air intake. And an electric pump. It runs lean and has electric assistance.
It's awesome.
I like the other slow burning stove that doesn't need any outside help. I see you opened the bottom vent, and it worked better.
I want to see a rematch.
Agree.
What a guy !! Climb that roof,fill that pipe 😊 my kind of guy 😊. Love ya man ... Always remember bro, the player haters will Always Criticise... 🙏🏻🏴
Dude just went "i am very strong" lmao
I got jokes..
I'm learning how to use tools based on these videos. I show my friend these videos and he said he would show me how to use each tool.
Been waiting for this one
Kudos to you sir, for working so well with that 'tricky to work', but neat looking round tubing. Bravo! 🔥🚀
Honestly, good on you for not taking the freezing the pipe idea. It just sounds like a bad idea considering water expands when turned into ice meaning it would risk destroying the pipe. Also using salt or something that would dissolve in water in theory makes sense, but then you consider that you're using dry sand in a pipe with relatively gentle bends. Just use compressed air afterwards to blow the sand out then use some water to make sure any extra dust left behind is rinsed out.
Should sleeve the outside with steel and fill it with sand instead of exhaust wrap. Sand is great and holding and distributing heat. Also the compression fittings need to be lubed with Vaseline to really work correctly.
Love the design, i would love to see a very portable version of this.
Perhaps in the future I will experiment with a back packing collapsible rocket stove with the coil inside. But if you beat me too it I would thoroughly enjoy that video.
Cool work!
This is about as portable as it's getting honestly. Collapsible and copper coils don't really go together.
That's the smartest looking design I've seen extent!!!!
Outstanding young🌱 man 👏!!!!!
Mine heat's a 150 gallon hot 🥵 tub in an hour maybe 70 minutes except a little taller and it's a six inch diameter version but one could easily say the look like twins!!!!
No pump nessesary water 💧💦 in at the bottom and the heat rise's it up in the top!!!!
For the thermo-syphon, its best to leave the return hose above the water surface. This allows for much easier one-way flow.
For the pumped system, water should enter at the top if the coil and exit the bittom. This makes for more efficient heat transfer, as the temperature differential is higher.
Having the coil in the exhaust flue is going to.extract much more heat, as the exhaust gasses will contact the entire surgace are of the coil.
Great video
😮 Wow ! That's a genius water heater, your very good men, professional very creative ! Congratulations 💥
Pump works best because heat conduction is best when temperature difference is greatest and pump ensures this difference by replacing hot with cold quickly. Nice build.
I'm absolutely baffled! A thermosiphon! This is incredible!
FUCKING HOLY SHIT BUD, Hail State! Wtf?! 🤘
This video is really awesome learning thru someone's great efforts and experience. Nice job
Great work man!
Next time you run a test, either have a pump to cycle water for both or neither. I believe that having that pump cycle the water helped to heat it up faster.
Thanks for showing us your hard work, I really appreciate it😁
Making things really teaches you through experience.
People can criticise all they want, but do they show you what they make? 😉👍
I’m sure there are already tons of comments but if your pumping one through the heat exchanger and the other relying on thermal flow , the pumped one will work way better and because it’s using absorbing more heat faster you’ll have to feed it more.
Cool video though.
Firstly, props for building these. Do they smoke? I wonder if you slid the copper coil up the chimney some you might actually get more energy out. Could be that cooling the combustion chamber would reduce combustion efficiency. I'd be interested if that changes the power output, up or down.
If you want the coppercoil tight roll it on a log slightly smaaller than you exhaust chimney and push it on.👍👍👍 cool stove!
Thank you. Great to actually see an honest experiment.
Very impressive designs, lots of potential!!!
Thay second unit with the pipes on the outside I believe is the safer and better option. My brother is a plumber and lived off grid for a while and made something similar. When I asked if he would get more heat from the copper being in the flames, I recall he said something about its not good, as direct heat makes copper emit something. I can't remember what.
He had his pipes on the outnaide with another layer of metal wrapped around that, likenyou have the thermal tape.
Also, look up convection and conduction, as these two bits of science may also help you get the transfer of heat sooner (I'm a firefighter).
07:50 I like the pop sound of the welder in these time-lapses. Kind of soothing. 🤙🏽
I really like the look of the copper-outside stove even if it doesn't turn out as efficient.
The first iteration had greater surface area of piping in contact with greater temperature air. Its not a surprise it operated better.
The inlet crossectional area will be directly correlated with air intake as a ratio to fuel blocking airflow. Of course the first will eat fuel more its got a larger air intake to stoikiometrically mix with fuel.
Try a tighter coil that sits proud of the internal wall. You could also double heat by having tube within a tube venting exhaust through inside and water between pipes.or pre-heating externally, then heating internally.
I wonder if a dule offset inlet generating a spiral airflow might also generate additional heat. Whether that would work as a heater idk. Fun to design
Very nice side by side comparison. Seems like a combination of both designs would make for a very efficient heater
It the prettiest rocket stove I’ve ever seen ❤
11:20 best quote I've heard on TH-cam this year. That or 'don't do anything dum, dangerous or different'. Extra points if you know.
Subbed 🤙
Edit, kudos on finding out the olive terminology 👍