If you put a metal sleeve over the outside, you'll get much better heat transfer. Right now you're only getting conduction. Adding an outer sleeve will help retain some of the heat and allow for convection as well.
@@d0uble_O No, just another larger diameter steel sleeve. Leave it open on the bottom, and the rising heat would induce convection to transfer more heat to the entire surface of the copper pipe. The copper pipe would be sandwiched between the inner steel burner can and an outer steel sleeve.
Was looking for this suggestion and was going to write it myself. Wrap the outer sleeve with some insulation and concentrate the heat transfer to the tubing
If you move that coil up past the top of the chimney you will get hot quicker. The copper tube will get soot on it. I built a similar unit and was able to put out about a half gallon a minute of steaming hot water using no pump, just a check valve basically designed lime an electric percolator coffe pot. I like your setup very neat and clean. Great job!
5 gallons of water from 37°F to 140°F within one hour means you have achieved an average heating power at around 1.2 kilowatts. Putting the bucket directly on top of the flames, you propably would have had more than twice the power (but a sooty pot base)
If you know @ 25 °C the volumetric heat capacity of the water is 4 181,3 J⋅kg-1⋅K-1, then if you have the starting temp, the final temp et the amount of water it's easy ;) 😁
@@stevothegreat hot water rises to the top as it's lighter. And cold water sinks to the buttom. So the system constantly takes cold water from the bottom of the tank into the heater coil. And as the water gets hot, it circulates back into the tank. This only works if the tank is raised above the fire
cool setup, this method has been used for a 100 years to get hot water, pipes running in the fire place in a cabin to a hot water tank, one time the water got so hot it started to boil in the tank, we had to put out the fire.
Very cool man. If you did a steel pot you could put it on top of fire. Woyluld be cool to see boil time wirhout the copper line on the fire vs with the copper line on fire.
Since it’s water filled , you could put the coil inside the rocket stove pipe? As long as it is always full when you operate it, it would not burn out the pipes . It might heat twice as fast? Clean off soot with a wire brush once in no a.while.
If placed inside the hot flue gas, stretch out the coil so it is loose, heated on all sides. Dissimilar metals may cause corrosion, so avoid direct contact by using insulating couplings and stand-offs. Hot flue gas rushing up the center is totally wasted. Plug up the center area with a cylinder of firebrick or use closed-off metal tubing.
I lived on a tiny sailboat for years and years. I only had a wood stove. This is exactly how I heated water. A coil of copper to wrap around the metal chimney attached to a tank. I could also use that copper coil and rigged it up with a pressure cooker and make an ersatz desalinator.
I'm a live aboard, off-grid for 36 years... Put pan of water above chimney of stove (in video) boils quick. There's a YT video of a rocket mass stove (in house) height, width, length of a snooker table (also heated water) .. bit too heavy for my boat.
Thats how we heat the shower water in our sauna. The water tank is a thick stainless tank mountes on the wall just above the sauna-stove. Once you get the room up to temp, the water is about ready too.
My grandparents have a similar thing wrapped around the chimney in their house to aid the hot water system when the fire is on. It's not a complete replacement as the fire isn't always on, but it definitely saves them money on their power bill
Yes, I agree. Also, constrain the hot gasses to run only near the metal surfaces, filling the flue with ceramic fire brick down the center line. Hole saws can make discs of ceramic foam that you can string on all-thread or tubing. If you run the tubing inside, then stretch out the coil slightly, and expose it to hot flue air inside and out, top and bottom. No need to press tight against the flue interior; actually undesirable. I recommend stainless steel tubing instead of copper tubing for greatest longevity, but copper conducts far better.
@@bryniebear3547That's right and also they used copper for the cabling inside the pyramids. I mean, they hadn't been able to paint the Pharaos' bedroom without decent illumination, had they?
Super cool idea bro! I used an old transmission cooler with 2 lines and a small battery pump for circulation to heat up my camp shower. This is even better!
Would it be a bit more efficient if all the fire had to brush past copper pipe on its way up? Like a “coiled coil” going up inside the chimney leaving inch wide gaps for air to pass. Also fire stone insulation on the outside of the chimney would increase efficiency.
If you are looking for efficiency, this ain't it. You would be better off with a heat exchange sitting above the flue to catch most of the heat for two reasons: the obvious one but also because a rocket stove doesn't achieve regasification until the air is extremely hot, which is why a rocket stove needs to be insulated (this one is not so therefore it's not actually a rocket stove, it's just a stove in a shape that resembles a rocket stove.) By putting the heat exchange on the flue, the water robs heat from it and thus reduces the burn efficiency of an already crippled burn efficiency because not only is it lacking insulation but now the heat is being sapped to warm up water. This video is a case study in why design principles are important to understand before you go redesigning something.
pretty cool setup up. 2 ways I can see improving this: (1) your thermal interface between the coil and the tube needs to be improved. it is a function of surface area and the conductance of the interface. Because the tube is round you're only touching as a single point (think circle & tangent lline). find a thermal interface foam. (2) you're losing heat on the tube going out to the bucket. Add some insulation.
I have done the samething with my hot tub it will reach 120° from 45° in 40 minutes. A friend asked if it would would for a so I built and his shop floor is the only heat in the shop. Inside the shop is about 65° with outside temp of 28° not bad. Just make sure you don't stand the floor for to long in one spot your feet start to get warm. Now his wife wants one in the house also.
Nice build. Colder water moves to the bottom, while hot water moves to the top (convection). So, if you swap the bucket terminals, you should have a faster heat transfer....
Use 1/4" copper and it will be much more efficient. I built my first wood burning water heater decades ago. You can increase efficiency by using smaller tubing an just making it longer . You'll also get an increase if you add insulation around the outside of the copper. Just understand that if you do all that it will get so hot so fast it will melt through the rubber hose and plastic bucket. You'll get water coming out closer to 200°f . If you slow the water flow input it will come out as steam at 220° or higher.
The thing about any container filled with water is that it cannot get above the boiling point of water. Because it's not pressurised. The water heat up to 100c, and then boils off taking the heat with it. Majority of plastics can withstand 100c. Some might soften a little.
@@DIYToPen that’s why you’re able to boil water in a plastic water bottle over an open fire. I thought it was crazy when I first heard it but the science is sound.
I recently did a video where I built a square tube rocket stove with the copper on the inside. So I figured I’d continue to project and compare it to a round stove with copper on the outside.
Raise you copper coil higher. The point of the rocket stove is to keep the combustion area hot enough to burn the fuel completely, and that coil is cooling that area.
And insulate the flue too, especially for such a small rocket stove and one made out of steel. You're one of the only other people I've seen who understands the difference between a rocket stove and a stove that is J-shaped.
@danclay8229 the convection is inside the tubes. Convection is the tendency for a hot fluid to rise and a colder fluid to fall into the empty space. The heat transfer from the stove to the copper tube is conduction. The tendency for hot water to rise upwards through the top of the coil and cold water to be pulled through the bottom tube into the bottom of the coil is convection. Fluid is another confusing term. A fluid is anything that takes the shape of it's container. All gasses and all liquids are both fluids. The swirling of water inside a pot before it boils is convection. The "rocket" affect of the stove is convection. A deep fryer works through convection. A convection oven, aka "air fryer," uses a fan to create artificial convection.
I admit my understanding is probably rudimentary at best, but given the explanation above, wouldn’t this convection be more productive if the “intake” at the bottom of the copper coil came from the top of the water bucket & the “discharge” of the coil exits into the bottom of the bucket… decreasing the heat that me by convection in the bucket as well?? Just a question… I don’t have the answer…
Exact same principle as an old gravity feed hit water boiler. The boiler below heats the water and the water rises and circulates up to the bucket-house, heating it and returning back downstairs to the boiler. Nice. You half way invented home heating from the 40s on up.
This is called natural circulation. Gravity feeds water to the coil from the bottom and as it heats it rises and flows back to the bucket via the top tube. if you increase the efficiency by sleeving the coil and insulating the bucket (or other tank) you will turn this from a hot water heater to a steam generator. If you turn the bucket into a pressure vessel you can then use the steam to propel a prime mover / electrical generator set up. electricity from a wood burning rocket stove would be pretty cool!
Yes, the principal is easy. Hot water rises, and cold water goes down . We had our central heating going that way and our hot water cilinder too . All on gravity feed . But you have to lay the pipes in a particular way , and the pipe has to be thicker . Made a boiler in our wood stove. Done many years of service. We had no electricity at that time .
This seams like it could be a good idea to help heat the floor during winter months. If able to be incorporated to an existing wood stove. Very interesting good share!❤
And you think that's the most important concern here? What about the fact that the radiant heat from the pipe being allowed to escape into the atmosphere and the fact that the wrapped copper is not at the top of the pipe where it's the hottest? This is intended to get comments about how inefficient the design is, not how the camera makes the pail look small.
@user-un9lx4kp6u i thought the same..he has a temp gun, could have cought that easy..but thats an easy fix, just scoot the coil upwards..what i also noticed that it should have an automatic wood feeder to keep the flame going and a ash dispenser to not have that area clogged with ashes and put out the flame.
@@PatrickRemington I've made one similar to this with 3" automotive exhaust pipe. I also put an old paint mixer in the vertical pipe and wrapped with rockwool for a rocket-stove mass heater experiment. Also, a dropout at bottom for ash. Hot AF and even funner to experiment.
This isn't some magical free energy crap. Rocket stoves come in many shapes and sizes, and this one looks very well done. They're established tech, as is convection heating using a heat exchanger like the copper tubing shown here. You simply need to elevate the bucket and colder water naturally falls out the bottom to replace the heated water rising in the tubing. No offence, but if your experience is limited to stuff that plugs into the wall, maybe just cast about ye olde interwebbe for some further information before dissing stuff. The same copper tubing connected to the same (elevated) bucket and enclosed in a glass-covered box painted black and pointed at the sun will also do an impressive job of heating water, but it won't be as fast as this. There was a time in California (before oil changed everything) when you wouldn't dream of buying a house that didn't have a solar water heating system.
Use a metal bucket so you're not boiling plastic into your water. Put an outer cover on the copper to keep it from off gassing it's heat into the air, and make sure the stove can slip in and out of the coil since heat scales and thins steel so you can replace the stove. Looks good.
Add the center out of a gas hot water tank flue pipe. The baffles will slow the heat escape and provide more heat transfer to the copper. Just slowing down the exhaust a little will help efficiency
You're doing it the HARD way! Merely run a single length of 1/2" soft copper up the chimney / firebox INSIDE and attach the bottom hose to the lower end of the copper tubing, and the upper hose to the top end of the copper tubing. This will cause it to thermosiphon LICKITY-SPLIT. You'll have screaming hot water in no time. I do exactly the same on a 50-gallon tank on my homestead in Texas, fueling it with Oak wood pellets.
I did this in 02’ with large fires to heat the family pool. I was 12. Glad to see a reiteration. Most people don’t think to do types of things like that for thermal btu heating value.
I had an intention to add a system to my would stove. However I was going to use a radiator. But now I can use a bucket instead and eliminate the pump. It would be good instead of waking up at night and add wood.
4200 btu output water heater + cooking on top, sounds like a win👍🏼……could use rising heat to turn a circulator add a small radiator and you have a mini self sustaining (if you can find a way to auto feed fuel) boiler system to heat a tent or small bushcraft structure🤔
That’s a warm idea. No electricity how to circulate the water? Solar pump would be great. Some mention 1.2kw maybe can warm a small room. then have to add wood so often. Thanks for sharing your built ❤
This is a great design. Radiant floor heating or radiators would be possible. If you use some Thermo-Conductive Interface Material, you would become more efficient.
It would be neat to see a second layer of steel around the copper tube, but filled w sand. Sand holds heat for a long time and could extend your energy transfer great prototype
Maybe the 1/2 copper pipe can break into multiple capillary tubes so it holds the same volume of water but the amount of copper toching the barrel is greater.
I have attempted this by just placing the coiled pipe in a bonfire. One could get better results by just placing a pot on top of the rocket stove. You bring the water to boil, then add the same amount of cold water to it. Much faster.
Instead of a copper pipe wrap, you should have a double walled pipe with the water travelling the full lenght of the chimney. Maybe even make the chimney a bit longer too.
I’d insulate that bucket, put it level with the stove, use more copper tubing so it wraps the entire chimney, and maybe consider a different material for the chimney
I made one where the copper coil was inside the flue. On a test run before connecting it to the tank, I burnt just a couple of sheets of newspaper which caused the water preloaded into the coil to boil violently and spit out the top, falling on my head and burning my scalp, ouch! But very effective at heating up a tank of water.
It would heat up in circulate a little bit faster if you put the top hose coming from the copper into the bottom of the bucket and the bottom hose from the top of the bucket.
If you make another one you should solder the copper tubing to the steel, if you get enough solder between the joints and fully bond them (very possible with good surface prep and use of flux) the water in the tubing will wick enough heat from it to prevent it from melting, though you may want to get some kind of thermoelectric powered pump to get a little extra circulation going to ensure enough heat transfer. If all that tubing was soldered to the chimney tube you would probably triple the boil speed, as it sits there is _very_ little thermal transfer between the steel chimney tube and copper coil. What would _really_ work well is putting the coil inside the chimney, though I'm sure there would be some longevity issues, I doubt the copper could take that kind of heat for long, oxidation would become a problem. Also, wrap that thing in glass wool, lots of wasted heat is radiating off the coil.
Your natural convection water movement system will not keep working when the water gets hot enough.There needs to be enough of a temp diff between the top and bottom hose. when it gets hot enogh there will be very little.Then you will see the water in the coil boil and spit steam into your tank.Consider some small pump-doesnt have to be big ,just has to make sure there is always moving water in the coil.You need a bigger tank too.
If you put the stove underneath the container of water.....i mean the coil is very useful but it's actually easier than that to dump heat into an elevated container
I'd recommend adding 18 in of copper on the inlet and outlet, it's so the pex doesn't break down and add harmful chemicals it is rated for high temperature but upc and IPC code on water heaters and tankless demand at least 18 in of metal before cpvc or pex can be used.
Thanks for 2M views!! ❤❤
This is awesome
That's such a clean design and the welds look amazing 👍
What happens when the watrer in the coil boils? It turns to steam and eexplodes.
BPA water!
@@newbluerugby copper doesn't have a BPA coating genius.... SIGH
Go whinge about your chemtrails .... LoL
If you put a metal sleeve over the outside, you'll get much better heat transfer. Right now you're only getting conduction. Adding an outer sleeve will help retain some of the heat and allow for convection as well.
you mean like the ceramic/titanium wrap for exhausts?
@@d0uble_O No, just another larger diameter steel sleeve. Leave it open on the bottom, and the rising heat would induce convection to transfer more heat to the entire surface of the copper pipe.
The copper pipe would be sandwiched between the inner steel burner can and an outer steel sleeve.
Was looking for this suggestion and was going to write it myself. Wrap the outer sleeve with some insulation and concentrate the heat transfer to the tubing
And pipe the exaust downward to increase efficiency.
If you move that coil up past the top of the chimney you will get hot quicker. The copper tube will get soot on it. I built a similar unit and was able to put out about a half gallon a minute of steaming hot water using no pump, just a check valve basically designed lime an electric percolator coffe pot.
I like your setup very neat and clean. Great job!
I wouldn't advise drinking or washing in water that was near boiling point while in Vinyl.
Definitely not.. this is just a test setup for a video. using clear lines to be able to see what’s happening
Shower an dish washing water.
It's probably food grade tubing
@Shojohn11 I think he means the bucket. If it was a food grade, non leaching, it would probably be okay.
@@kdigiacomoGotcha, that makes sense thanks
5 gallons of water from 37°F to 140°F within one hour means you have achieved an average heating power at around 1.2 kilowatts.
Putting the bucket directly on top of the flames, you propably would have had more than twice the power (but a sooty pot base)
If you know @ 25 °C the volumetric heat capacity of the water is 4 181,3 J⋅kg-1⋅K-1, then if you have the starting temp, the final temp et the amount of water it's easy ;) 😁
Probably wouldn't get much soot as the fire looks to burn pretty clean.
Probably a hole in the plastic pot shown as well
How is the water circulating through the system ?
@@stevothegreat hot water rises to the top as it's lighter. And cold water sinks to the buttom. So the system constantly takes cold water from the bottom of the tank into the heater coil. And as the water gets hot, it circulates back into the tank. This only works if the tank is raised above the fire
My grandpa has something like that in his back yard but he stores his water in clear jars instead of a bucket
Put a stainless coil on 40 % better heat propagation...
@@user-on6xv2or4lDisculpame, no es así, el acero inoxidable es un mal conductor de temperatura.
Jajaja 100% alcohol
Mine too! Right next to his special okra plants.
Dowwwwn the road here from me, there's an old holler treee
My uncle has one just like this in his shed off in the woods. Doesn’t want anyone talking about it though for some weird reason.
😂😂😂lol, because it has something to do with a bright shining moon?
He's distilling water, don't give the boy ideas.
so stop talking about it
Moonshine
@@mulberry9292 😅😅😅😅
Well played sir!
Build one out of 4 inch, then weld a 6 inch sleeve around it that could be completely filled with water. 100% constant contact
If what your saying is as im picturing it would loose its pumping action....
I was thinking just build the flame tube into the side of a stainless steel bucket with a tap at the bottom, like a tea urn.
You've created a pressure vessel and therefore potential explosion .
You'll need a thermostat like in a car motor.
For reliable psi relief
Sleeve around the copper and move the copper up to the top of the tube where it’s hotter.
cool setup, this method has been used for a 100 years to get hot water, pipes running in the fire place in a cabin to a hot water tank, one time the water got so hot it started to boil in the tank, we had to put out the fire.
Great for a camp shower, we used to set up 55-gallon drums painted black and the water was super hot from the Sun in Arizona
In Arizona I would want a cold shower
@@SteRob-ky1wtyou'd be surprised. The high country in AZ is just as cold as anywhere else
@SteRob-ky1wt No doubt. I was a surveyor in Zona and used to dump gallon jugs of water over my head in the 115 degree summer.
Thanks!
Facts @@desertBirdDogs up there near the San Francisco peaks in coconino county it gets extremely cold.
Very cool man. If you did a steel pot you could put it on top of fire. Woyluld be cool to see boil time wirhout the copper line on the fire vs with the copper line on fire.
Since it’s water filled , you could put the coil inside the rocket stove pipe? As long as it is always full when you operate it, it would not burn out the pipes . It might heat twice as fast? Clean off soot with a wire brush once in no a.while.
If placed inside the hot flue gas, stretch out the coil so it is loose, heated on all sides. Dissimilar metals may cause corrosion, so avoid direct contact by using insulating couplings and stand-offs.
Hot flue gas rushing up the center is totally wasted. Plug up the center area with a cylinder of firebrick or use closed-off metal tubing.
I lived on a tiny sailboat for years and years. I only had a wood stove.
This is exactly how I heated water.
A coil of copper to wrap around the metal chimney attached to a tank.
I could also use that copper coil and rigged it up with a pressure cooker and make an ersatz desalinator.
Nice!! But according to these comments, THIS IS THE MOST INEFFICIENT WAY POSSIBLE!! 😂😂😂
Où trouve t'on le bois sur un voilier 😂
dans mon petit casier a' acool😉
I'm a live aboard, off-grid for 36 years... Put pan of water above chimney of stove (in video) boils quick.
There's a YT video of a rocket mass stove (in house) height, width, length of a snooker table (also heated water) .. bit too heavy for my boat.
@@PatrickRemington everyone's an expert! If it works, it ain't stupid and all that.
Now you just have to put the chimney/exhaust under the water heater to capture even more of the heat.
Then he'll have built a regular hot tub.
Technically it would be called a water heater @@velianlodestone1249
Thats how we heat the shower water in our sauna. The water tank is a thick stainless tank mountes on the wall just above the sauna-stove. Once you get the room up to temp, the water is about ready too.
@@TheMagicalTouchGood idea
you forgot to mention that depending upon where you live, it cost from $0.00 to $0,40 to have enough hot water for a shower.
My grandparents have a similar thing wrapped around the chimney in their house to aid the hot water system when the fire is on. It's not a complete replacement as the fire isn't always on, but it definitely saves them money on their power bill
Love it... just came by a plastic recycling ♻️ numbers that are okay to heat and eat/drink from...
Stay safe
That would be cool if it was hooked up to an in-floor heating system
They make those. Usually uses a glycol fluid in the system.
in-floor heated tent, way cool!
they use pumps because natural heat movement of water wouldn't be enough and it would overheat
Yes. And working on petrol and also remotely connected to an app
Used to make boilers for your house that did the same thing. Worked great when the power went out.
Put the copper tube IN the rocket stove. The heat transfer will be way higher.
Anyways well done. Looks like a fun project.
Yes, I agree. Also, constrain the hot gasses to run only near the metal surfaces, filling the flue with ceramic fire brick down the center line. Hole saws can make discs of ceramic foam that you can string on all-thread or tubing.
If you run the tubing inside, then stretch out the coil slightly, and expose it to hot flue air inside and out, top and bottom. No need to press tight against the flue interior; actually undesirable.
I recommend stainless steel tubing instead of copper tubing for greatest longevity, but copper conducts far better.
That’s great we will be checking for the whole video…keep up the great work!!!👋😃👋
Reminds me of when Moses wandered for years, searching for twenty feet of copper tube he could use to heat a primitive shower.
Dude, copper was fairly common in ancient Egypt. Archeologists believe the stone for the pyramids was carved using copper chisels
@@bryniebear3547thats a joke right. Lol
Copper vs. stone, stone always wins@@bryniebear3547
@@bryniebear3547That's right and also they used copper for the cabling inside the pyramids. I mean, they hadn't been able to paint the Pharaos' bedroom without decent illumination, had they?
I thought Moses needed the copper tubing for a pot still, something about needing to turn the water into wine or whatever.
You have to move tubing 4” higher and insulate as you are losing so much heat.
The pipe is cooler the higher it goes.
Had a similar setup 4 55gallon drums. Each drum had 45 ga. Manifold setup for the tubing. Heating chicken coop and rabbit hutch. Worked great.
Cover the copper with insulation and another layer of pipe and it will gain some more efficiency! Kind of like a diesel steam cleaner
Yeah I’m going to try exhaust wrap and see how that does.
@@PatrickRemingtonIve heard superwool is the way to go
@@PatrickRemington. Wood stove gasket material worked fine on my Hooker Headers on 650 Yamaha.
Diesel steam cleaners or the kettle as we call it have the tubes in the fire
@@ninetyninerising9482asbestos 👌🏻
Super cool idea bro! I used an old transmission cooler with 2 lines and a small battery pump for circulation to heat up my camp shower. This is even better!
Would it be a bit more efficient if all the fire had to brush past copper pipe on its way up? Like a “coiled coil” going up inside the chimney leaving inch wide gaps for air to pass.
Also fire stone insulation on the outside of the chimney would increase efficiency.
If you are looking for efficiency, this ain't it.
You would be better off with a heat exchange sitting above the flue to catch most of the heat for two reasons: the obvious one but also because a rocket stove doesn't achieve regasification until the air is extremely hot, which is why a rocket stove needs to be insulated (this one is not so therefore it's not actually a rocket stove, it's just a stove in a shape that resembles a rocket stove.)
By putting the heat exchange on the flue, the water robs heat from it and thus reduces the burn efficiency of an already crippled burn efficiency because not only is it lacking insulation but now the heat is being sapped to warm up water.
This video is a case study in why design principles are important to understand before you go redesigning something.
That’s called a tankless coil brother
They’re in most boiler and hot water heater systems already
Thats actually awesome
Thank you!
pretty cool setup up. 2 ways I can see improving this: (1) your thermal interface between the coil and the tube needs to be improved. it is a function of surface area and the conductance of the interface. Because the tube is round you're only touching as a single point (think circle & tangent lline). find a thermal interface foam. (2) you're losing heat on the tube going out to the bucket. Add some insulation.
I freaking love harbor freight man i do inspections and love that little laser thermometer
It has been great!
I've always wanted to try this but with a hot tub
We did the same process in a hot-tub on a trailer for a mountain party. Work perfect!
Same!
Yeah, yah really just want to soak up all the micro plastics into every pore of your body
@@blablableep6811 is showering with city water any better?
@@blablableep6811lol you guys won’t stop with that crap. It makes you sound like the craziest of conspiracy theorists.
I have done the samething with my hot tub it will reach 120° from 45° in 40 minutes. A friend asked if it would would for a so I built and his shop floor is the only heat in the shop. Inside the shop is about 65° with outside temp of 28° not bad. Just make sure you don't stand the floor for to long in one spot your feet start to get warm. Now his wife wants one in the house also.
Nice build. Colder water moves to the bottom, while hot water moves to the top (convection). So, if you swap the bucket terminals, you should have a faster heat transfer....
Use 1/4" copper and it will be much more efficient. I built my first wood burning water heater decades ago. You can increase efficiency by using smaller tubing an just making it longer . You'll also get an increase if you add insulation around the outside of the copper. Just understand that if you do all that it will get so hot so fast it will melt through the rubber hose and plastic bucket. You'll get water coming out closer to 200°f . If you slow the water flow input it will come out as steam at 220° or higher.
Curious about what the melting point is for the plastic bucket 🪣? I probably wouldn’t drink the water but I’m sure it’s good for a hot bath! 😊
The thing about any container filled with water is that it cannot get above the boiling point of water. Because it's not pressurised. The water heat up to 100c, and then boils off taking the heat with it. Majority of plastics can withstand 100c. Some might soften a little.
@@DIYToPen that’s why you’re able to boil water in a plastic water bottle over an open fire. I thought it was crazy when I first heard it but the science is sound.
@@kenmccrady1228 you can boil food in a paper pot this way i've heard
@@felixfarquharson science is so cool, isn’t it?
Is there a reason the copper is on the outside of the exhaust? Or just easier for testing?
I recently did a video where I built a square tube rocket stove with the copper on the inside. So I figured I’d continue to project and compare it to a round stove with copper on the outside.
Yeah I thought it looked rather backwards.
I'm gonna guess the copper on the inside works at least twice as well if not better.
@@charmio It has definitely been a proven method for at least 150 years it's how boilers operate.
@@JayRSwan
Steam Locomotives ran hot flue gas through many parallel copper tubes. Boiler water outside.
Raise you copper coil higher.
The point of the rocket stove is to keep the combustion area hot enough to burn the fuel completely, and that coil is cooling that area.
And insulate the flue too, especially for such a small rocket stove and one made out of steel.
You're one of the only other people I've seen who understands the difference between a rocket stove and a stove that is J-shaped.
Very clean build. (You could also put a stock pot full of water on top) 😉
The first guy l have seen who understands how convection works. Well done 👍👍👍✅
You mean conduction right? I guess convection from fire to stove wall and the stove wall touches copper coil then coil to water. So both.
Needs a better heat exchanger.
@danclay8229 the convection is inside the tubes. Convection is the tendency for a hot fluid to rise and a colder fluid to fall into the empty space.
The heat transfer from the stove to the copper tube is conduction. The tendency for hot water to rise upwards through the top of the coil and cold water to be pulled through the bottom tube into the bottom of the coil is convection.
Fluid is another confusing term. A fluid is anything that takes the shape of it's container. All gasses and all liquids are both fluids.
The swirling of water inside a pot before it boils is convection. The "rocket" affect of the stove is convection. A deep fryer works through convection.
A convection oven, aka "air fryer," uses a fan to create artificial convection.
I admit my understanding is probably rudimentary at best, but given the explanation above, wouldn’t this convection be more productive if the “intake” at the bottom of the copper coil came from the top of the water bucket & the “discharge” of the coil exits into the bottom of the bucket… decreasing the heat that me by convection in the bucket as well?? Just a question… I don’t have the answer…
@@danclay8229water is a fluid. As is air. It is convection
Exact same principle as an old gravity feed hit water boiler. The boiler below heats the water and the water rises and circulates up to the bucket-house, heating it and returning back downstairs to the boiler. Nice. You half way invented home heating from the 40s on up.
Actually, gravity fed boilers were around in the 18th century already.
This is called natural circulation. Gravity feeds water to the coil from the bottom and as it heats it rises and flows back to the bucket via the top tube. if you increase the efficiency by sleeving the coil and insulating the bucket (or other tank) you will turn this from a hot water heater to a steam generator. If you turn the bucket into a pressure vessel you can then use the steam to propel a prime mover / electrical generator set up. electricity from a wood burning rocket stove would be pretty cool!
Yes, the principal is easy. Hot water rises, and cold water goes down . We had our central heating going that way and our hot water cilinder too . All on gravity feed . But you have to lay the pipes in a particular way , and the pipe has to be thicker . Made a boiler in our wood stove. Done many years of service. We had no electricity at that time .
You need the tube in the flame
Got a whole build video on that: th-cam.com/video/8eu87nutyOM/w-d-xo.htmlsi=2_TxH0weh9cy1g7A
It could easily melt the copper
@@DMIsREAL use a material that won't melt - copper melting point is 1900 degrees tho
@@malootua2739. I liked the idea of just setting a steel container on a fire.
This seams like it could be a good idea to help heat the floor during winter months. If able to be incorporated to an existing wood stove. Very interesting good share!❤
great job! thanks from Brazil
That's the smallest 5 gallon bucket I've ever seen...and it was only about 2/3 full👎👎
😂😂😂
And you think that's the most important concern here? What about the fact that the radiant heat from the pipe being allowed to escape into the atmosphere and the fact that the wrapped copper is not at the top of the pipe where it's the hottest? This is intended to get comments about how inefficient the design is, not how the camera makes the pail look small.
@user-un9lx4kp6u i thought the same..he has a temp gun, could have cought that easy..but thats an easy fix, just scoot the coil upwards..what i also noticed that it should have an automatic wood feeder to keep the flame going and a ash dispenser to not have that area clogged with ashes and put out the flame.
@@user-un9lx4kp6ubut the top of the pipe isn’t the hottest. Not by a long shot.
@@d0uble_O but the top of the pipe isn’t the hottest. Not by a long shot.
BULL S. SET UP.
How???
He trolling lol. Im gonna build something like this for an homestead hottub. This design is really informative. Thanks for sharing! :)
@@PatrickRemington I've made one similar to this with 3" automotive exhaust pipe.
I also put an old paint mixer in the vertical pipe and wrapped with rockwool for a rocket-stove mass heater experiment. Also, a dropout at bottom for ash. Hot AF and even funner to experiment.
This isn't some magical free energy crap. Rocket stoves come in many shapes and sizes, and this one looks very well done. They're established tech, as is convection heating using a heat exchanger like the copper tubing shown here. You simply need to elevate the bucket and colder water naturally falls out the bottom to replace the heated water rising in the tubing.
No offence, but if your experience is limited to stuff that plugs into the wall, maybe just cast about ye olde interwebbe for some further information before dissing stuff.
The same copper tubing connected to the same (elevated) bucket and enclosed in a glass-covered box painted black and pointed at the sun will also do an impressive job of heating water, but it won't be as fast as this.
There was a time in California (before oil changed everything) when you wouldn't dream of buying a house that didn't have a solar water heating system.
Use a metal bucket so you're not boiling plastic into your water. Put an outer cover on the copper to keep it from off gassing it's heat into the air, and make sure the stove can slip in and out of the coil since heat scales and thins steel so you can replace the stove. Looks good.
Sweet prototype. Practical, too!
Look how neatly it's built
Gravity and heat transfer, genius! 😊
Thanks for sharing your way,the rocket stove is really nice too
Thank you!
Just put water in metal bucket and start fire under the bucket, no electricity needed and much faster and safer. Old is gold.
Totally Cool !
Add the center out of a gas hot water tank flue pipe. The baffles will slow the heat escape and provide more heat transfer to the copper. Just slowing down the exhaust a little will help efficiency
Really Cool !! Thanks!!
Excellent work. Just by your thermometer, I knew you were legit.
You can have a second coil of copper tubing that is plunged down at the top of the stove. The tube wont melt if it is full of water.
wow very efficient at 6%. not bad at all. very fast too.
You're doing it the HARD way!
Merely run a single length of 1/2" soft copper up the chimney / firebox INSIDE and attach the bottom hose to the lower end of the copper tubing, and the upper hose to the top end of the copper tubing. This will cause it to thermosiphon LICKITY-SPLIT. You'll have screaming hot water in no time.
I do exactly the same on a 50-gallon tank on my homestead in Texas, fueling it with Oak wood pellets.
..niiice. thanks for posting and displaying your brainstorms of complex simplicity for better efficiency.
Keep informing the people...
I did this in 02’ with large fires to heat the family pool. I was 12. Glad to see a reiteration. Most people don’t think to do types of things like that for thermal btu heating value.
I had an intention to add a system to my would stove. However I was going to use a radiator. But now I can use a bucket instead and eliminate the pump. It would be good instead of waking up at night and add wood.
Down drafts outer chamber with secondary combustion preheated air before taking heat for water would ramp the efficiency up greatly.
4200 btu output water heater + cooking on top, sounds like a win👍🏼……could use rising heat to turn a circulator add a small radiator and you have a mini self sustaining (if you can find a way to auto feed fuel) boiler system to heat a tent or small bushcraft structure🤔
Wrap the bucket and the tubing with al foil, steel bowl for lid,reduce loss off heat ,perhaps.
That’s a warm idea. No electricity how to circulate the water? Solar pump would be great. Some mention 1.2kw maybe can warm a small room. then have to add wood so often. Thanks for sharing your built ❤
Convection circulates the water. No pump needed. Buy it could help.
This is a great design. Radiant floor heating or radiators would be possible. If you use some Thermo-Conductive Interface Material, you would become more efficient.
Very good! Using the laws of thermodynamics to your benefit and also allowing for a max coolness factor!
Use a stainless tub and all copper lines. No plastic.
It would be neat to see a second layer of steel around the copper tube, but filled w sand.
Sand holds heat for a long time and could extend your energy transfer
great prototype
Use CPVC or PEX over vinyl & nylon. CPVC and PEX are rated for high heat and pressure, including drinkable water.
Maybe the 1/2 copper pipe can break into multiple capillary tubes so it holds the same volume of water but the amount of copper toching the barrel is greater.
Compact. Smart design.
Thanks for supporting advance auto parts sir, we appreciate your business.
Not a bad idea. Not sure if encasing the tubing will help, though there doesn't seem to be adaquate space for ash.
A heat shield for the copper coil might help. Something simple that just drops over the coil.
Good job !!! ♥️💪👍
Iv got some stainless tubing of all sizes...im going to make one of these..all you really need is luke warm water for bathing...love this concept
I would love to have one of those for being out in the bush in Alaska
I have attempted this by just placing the coiled pipe in a bonfire. One could get better results by just placing a pot on top of the rocket stove. You bring the water to boil, then add the same amount of cold water to it. Much faster.
the most amount of heat is where you see the flame.....put the coil up and inside, big difference!!!
Like I said earlier it's the smartest design I've seen on TH-cam yet!!!!
You're losing 40% of heat to the air, put a sleeve over it and you'll improve the efficiency. Great build though, well done. 👏🏻
Instead of a copper pipe wrap, you should have a double walled pipe with the water travelling the full lenght of the chimney. Maybe even make the chimney a bit longer too.
That's brilliant.
I’d insulate that bucket, put it level with the stove, use more copper tubing so it wraps the entire chimney, and maybe consider a different material for the chimney
I made one where the copper coil was inside the flue. On a test run before connecting it to the tank, I burnt just a couple of sheets of newspaper which caused the water preloaded into the coil to boil violently and spit out the top, falling on my head and burning my scalp, ouch! But very effective at heating up a tank of water.
Put baffles in the flue, half circles, angled slightly up, and alternate. The pipe will get much hotter
great build
I'd like to see someone build a fresh water condenser similar to this
It would heat up in circulate a little bit faster if you put the top hose coming from the copper into the bottom of the bucket and the bottom hose from the top of the bucket.
If you make another one you should solder the copper tubing to the steel, if you get enough solder between the joints and fully bond them (very possible with good surface prep and use of flux) the water in the tubing will wick enough heat from it to prevent it from melting, though you may want to get some kind of thermoelectric powered pump to get a little extra circulation going to ensure enough heat transfer. If all that tubing was soldered to the chimney tube you would probably triple the boil speed, as it sits there is _very_ little thermal transfer between the steel chimney tube and copper coil. What would _really_ work well is putting the coil inside the chimney, though I'm sure there would be some longevity issues, I doubt the copper could take that kind of heat for long, oxidation would become a problem.
Also, wrap that thing in glass wool, lots of wasted heat is radiating off the coil.
Consider attaching the tube coming of the top of the rocket tube to the bottom of the bucket may quicken the heating time
Very cool!
I'd space the coils, and come farther up the stove.
Brilliant work.
Your natural convection water movement system will not keep working when the water gets hot enough.There needs to be enough of a temp diff between the top and bottom hose. when it gets hot enogh there will be very little.Then you will see the water in the coil boil and spit steam into your tank.Consider some small pump-doesnt have to be big ,just has to make sure there is always moving water in the coil.You need a bigger tank too.
the copper pipe should be inside the tube. steel is cast in water cooled copper moulds. if water is circulating enough , the coipper wont melt
@@jeetenzhurlollz8387 yes I know, I have several full length videos on it.
If you put the stove underneath the container of water.....i mean the coil is very useful but it's actually easier than that to dump heat into an elevated container
What a nice idea ❤
I'd recommend adding 18 in of copper on the inlet and outlet, it's so the pex doesn't break down and add harmful chemicals it is rated for high temperature but upc and IPC code on water heaters and tankless demand at least 18 in of metal before cpvc or pex can be used.
This is just for testing
Great idea