@@Ausomeoutdoors um nothing a larger pot wouldnt solve. In the pre-industrial age (back when everything was JUST fukn PERFECT and SO pure) They had fire underneath tha cast iron bathtub. Folks just sat RIGHT IN the pot with the water as it was being heated. So - thanks for playing.
@@ArtisanCustoms Oh. Wel...ok then. I dont want to boil water. I just wnat to make it luke warm...so why not use a process thats 10x less efficient and 1000 times harder and slower.......to make warm water. This is 21st century orange chimp logic if i ever heard it,.
If you start the cold water line at 3/4" and step it down to the size going down to the stove. This will create a head pressure that will help the flow greatly.
The process you're using for "passive heat exchange" is known as percolation which is what coffee makers use, and yes, it's supposed to sound that way and isn't sketchy at all as long as you have your system set up correctly. A good example for percolation hot water setup would be either soft copper tubing or copper flex lines connecting your stove to water storage and at the minimum a 45 elbow on the hot water return to aim the water toward the bottom or side of the bucket instead of allowing it to possibly belch up and out.
@@canaldopicco I stand corrected, you're correct that percolation is a filtration process. After taking a closer look at a coffee maker, which uses percolation filtration, I found that heat conduction creates convection currents to pump fluids.
Glad you followed up on this after all of the comments. I think an insulated lid on the bucket would help keep the heat in. Some sort of quick hose connections would be ideal for portability. The best use of the DC pump would be for actually using the water as a shower or washing dishes. Some sort of insulating cover around the jerry can or bucket would also maintain the hot water longer in cold weather conditions.
You can get Thermo Electric Generators that create 12v based on temperature difference. This could power the pump without a battery. If you trying it watch out for the max temperature as is may be to high for some TEG modules.
For future testing, to create more water pressure you would need to move the hotline higher than the current position. It’s about a difference in pressure between the lines not how high the bucket is from the stove. Overall this is a sick setup! :) love how clean it looks :)
With even more height difference it will work even better. The one that I saw working this way for a shower had the stove on the floor and the hot water tank overhead for the shower.
I use a similar setup while camping minus the rocket stove. I use a Harbor Freight transfer pump, some check valves and a bag style shower that I hoist up about 25 ft after the water is heated. It's made it to an extended discharge line with a valve at the shower head end. Works like a charm the bag of since water isn't light. LOL thanks for the video, might have to implement some of these ideas including but not limited to a modified coil
One thing that is worth mentioning is that you burned much less fuel with the passive, because of jow low you kept your fire going. Also, no need to be afraid of the sounds it makes ;) I really appreciate how you approach this with an open head and sharing uour thoughts along the way, instead of just editing it out to make yourself sound like a genius that came up with all of it himself. Thats awesome content thats missing online these days
It might be worth considering this in the light of rhe automobile industry. Early water-cooled car engines used the thermo-siphon effect, which incidentally is why they had tall, narrow radiators. Though this worked on very softly tuned engines, it was soon necessary to add s pump to the setup. As we saw here, with the pump included in the design, it was possible to carry lots more heat away.
🤣 Um have u ever seen early automobiles? Im talking like pre 1830's? Have u every heard of the steam engine? Do u have the faintest notion why its not practical in automobiles? Picture huge craters in the ground where there was once an automobile with a fat boiler and a wood-fueled burner. This is searchable on the Goggles.
yes and no. thermosiphon necessitates a casting that includes big, free flowing water passages... whereas forced cooling does not. here, proper design will work thermosiphon... the objective is to heat the water efficiently. the more water, the better. a car wants as little water as possible, as compact as possible... to be made as cheaply as possible... the water is there to dispose of heat, not store it. and yes, as performance goes up, the larger ports, valves, they demand more room, the cooling passages suffer, but theres more heat than ever to deal with... so they throw a pump on. and in the "good old days" they didnt even have decent seals for rotating shafts yet. bit of leather and a gland nut? some graphited asbestos rope? maybe a lead washer? do it up too tight and the shaft overheats and the bearing seizes... early pumps were temperamental! the pump works here because he doesnt have large, free flowing passages for thermosiphon to work properly...
Top ! , and the next thing …hook up a boiler and use copper to connect the boiler to the rocket heater ( open inlet for to fill the boiler ) and use thermo sifon to warm up the boiler ( and if you want to add a pump you can use a ( central heating pump ( wilo pump ) Water side pump ( they can stand heat ) Stay creative 👍👍 greetings from 🇳🇱 the netherlands
Very interesting video. It's great you were honest with the results. I'm thinking about adding something like this to my HWS so that when the grid is down, I can still have hot water. 👍
This works the same as the old range stove setups in the first half of last century (and possibly further back) that had what they called back boilers. Once the fire was lit in the range the hot water could travel upwards to the hot water cylinder/tank upstairs without a pump. This was before immersion heaters inside the same copper cylinders became the standard way to heat water if one didn't have a gas boiler and electric pump.
If you insulated the lines and the water container you’ll probably have less heat loss as well which will speed up the process. It would also hold the heat in the water longer. maybe use like one of those YETI bucket coolers instead of a regular 5 gallon bucket and retest. I bet it would work pretty fast with your electric pump set up. Great set up and testing so far though 👍
Thanks for posting this. Seems counter productive to have to reduce the amount of heat in the stove so the thermo syphon model works. Just on that alone I'd stick to using the pump and let the stove do what it can. Very simple heat exchanger. Have you tested the results if you wrap the heat exchanger in insulation? And the stove? Might get a bit too hot.
Insulate your water container, side, top and bottom. Something as simple as wrapping it in a 99c Mylar space blanket will make a HUGE difference in heat gain and heat retention.
Just as I suggestion you might put a couple short pieces of silicone rubber tubing at the fitting connections or just use all silicon tubing. Silicone tubing has a lot higher temperature rating than vinyl tubing at just over 500 degrees. I have a propane water heater that is a sheet metal box with a burner and a copper coil in it that circulates water the same way to heat the water. I was trying to cook at the same time I was trying to heat water and I wound up melting the vinyl tubing at the fittings. I replace the tubing with silicone and no more problem.
The reason it sound like an old coffee maker is because that it is actually not that dissimilar to how a coffee makers work. The main differences is basically a coffee maker heats the water using a heating element, but uses basically the same principle to pump the water though.
It would be cool to see how much difference there is with insulation around bucket (all sides) and possibly even the tubes. I don't know anything about this technology: it might not matter. Very interesting! I'm exercising on a stationary recumbent bike while working on my computer watching this. I think the gen 3 nuclear reactors use this type of passive heating. That way when the pumps fail at like Fukushima, the water keeps moving. I believe the same can be used with passive air heating from a thermal battery like sand.
I had a similar experiment with a hot tub I made (4000 liter - 1056 us gallon). But I ended up with feeding the hot water from the stow into the bottom of the hot tub and taking the top water from the hot tub into the bottom of the stow. My theory was that if i feeded the hot water from the stow to the bottom of the hot tub, the the hot water would rise an mix withe cold water in the rest of the hot tub. T hat would help speed up the heating process in general. I measured the time doing it like you have shown, cold water form the bottom - hot water into the top of the bucket and like I described, cold water from the top of the hot tub into the bossom of the stow and hot water from the top of the stow into the bottom of the hot tub. It was approximately 30 min more effective doing it the way I described it the the way you are showing. From approximately 10 deg. Celsius (50 deg. fahrenheit) to 40 deg. celsius (122 deg. fahrenheit). From 4 hours 30 minutes to around 4 hours. I did not use a rocket stow like you are using.
Patrick, I would love to see you build a DIY version of the Kammock Outpost hammock stand, Ive seen your other hammock builds and they are awesome, but the Kammock one is so niche and i would love to see your take on it! (I also think you could make it better, and cheaper than the real thing!)
I really admire you versatile DIY guys and I wish I had your skill set. But as something of a history nerd, aren’t you sort of trying to recreate a steamboat or steam locomotive in miniature? The boiler without the steam pressure? Anyway, there might be some insights to be gained by looking into boiler engineering…. Just an idea…
I wonder if you added a basic mechanical bulb type pump, similar to the type used from gas cans to old outboard motors, attached to the cold supply line that exits the bottom of you water reservoir. That may help eliminate the water from boiling immediately once the fuel source is lit and “jump start” or “prime” the system in the beginning to boost the initial siphoning effect. I’m sure there are scientific words to explain the physics of it. Not positive, but there must be a type of one way valve in those bulb style pumps to maintain fuel pressure until the motor is running and creating enough suction to draw fuel to the motor. I love your idea and follow up video that shows your improvements and using the community to improve your design. Excellent work. Great editing also. I’ve haven’t done much video editing but can assume that it’s time consuming and can make or break a video.
So, based on your numbers, your water heating power is equivalent to an electric heater that puts out ~1.2 kW. For comparison, a heater element on an electric stove typically uses ~1 KW of power. The total energy required to raise your water temp 30.4 °F is: ~1,306,905 J or ~1239 BTUs or ~363 Wh If you were using electricity at 12 ¢/kWh, it would cost you ~4.4 ¢/5 gallons or ~9/10 ¢/gallon. Given that 1 lb of dry white oak has ~6.4 million BTUs of energy in it, you are converting a very small amount of energy from 1 lb of wood for your water heating. If you keep track of the mass of the wood before & after the water reaches your ideal temp, you can even determine how efficient your wood heater is.
If you're looking at a 40 min shower as an example. You would need 60,000 btu for 80 to 100 gallons. A normal 80-gallon shower would use a little over 7 lbs hard season wood per shower maybe 10 lbs. This in return is a 40 min shower. The only drawback is it would take under normal operating conditions about 4 hours to heat the water of 100 gallons. If you had or made a pellet maker you could use anything for fuel. Also, if the water is strong enough with the heat you could run a small water generator by creating a strong current. The only worry I could think of besides lazy people could be potentially melting the Cooper coil. This a fun experiment for convention heating, but if you scale it up think of safety ( don't burn down your home or garage.)
Please try making a “spacer” for the top of your stove and set a 5 gal. pot on top and crank the heat all the way up. It will be interesting to know if your water comes up to temp faster with less fuel “wood” usage.
For the pump, you might try to use a thermopile or Peltier block. It may not run the pump quickly but might be enough to where you are not reliant on electricity. Great video; keep up the experiments!
How about making a very simple steam engine like system. When the water in the heat exchanger boils it shoots the water out. When the pressure in the heat exchanger drops cold water comes into the bottom. Basically it just needs a larger diameter section at the bottom of the heat exchanger.
Chimney damper would help control the heat some. For those that don't know why you would do this, try camping with no hot water. And no, not in an RV, but in a tent. Some hoses , a coil, and a dakota fire pit would do just fine in the woods.
Hi, I really like the idea very much. Actually I will build something simillar for a hot tub. It should heat up by day via absorbers on the roof, and the fire should bring it to the right bathing temperature. Please allow me a few ideas for improvement: 1. A bigger diameter should make a better thermal circulation 2. One valve for the cold water stopping from going back when boiling at the beginning 3. Isolate as much as possible to reduce loss of heat 4. As long as you can make bacon in a pan, you are wasting way to much energy. With your very clever stacable design, you could easily ad another chimney with copper inside. I would guess that at least one or two extra chimneys would work fine. But anyway, while I'm talking theory, you actually build something. Great 🎉
Not stupid, Japanese baths use a similar method to heat water in a community hot tub, wash before getting in, and rinse with water from a bucket then enjoy the warm soak.
I m not sure why you re worried about the boiling unless you re concerned with the pipe melting , but if you had copper delivery pipes the boiling wouldn't be an issue , more heat just means faster transfer into the bucket. I don't think any plastic is ideal for this operation.
I'm wondering if it will heat more quickly if the return tube is set higher than the bucket, then using gravity? One option would be to use a taller coil. Or possibly use a box style fill tank having a downslope for cold water and a downslope from the top of the heat exchange back to the tank.
You should try putting a copper coil in the cool side and then you don't need to cycle the drinking water through the stove. You might need higher pressure hoses and fixtures and a small reservoir to go with the coil on the cool side.
Probably to get the most flow you output back into the bucket should be above the water line. This makes the output go back to atmosphere and not under water and have to push against the weight of the water
I wonder how much heat is lost due to the not insolated bucked? I mean if I leave a bucket of hot water outside itll cool eventally and ye. Id be intrested in the difference
I wonder how this would work on a wood stove with having a coil brazed to the outside of a chimney section. That would help immensely for permanent stoves in cabins.
Not that this would improve the setup but itd be cool to see some tests with thermal probes at different depths to understand the rate at which the front of heated water makes its way down to the level of the reservoir outlet
coiled pipe is fine if you want a flash steam boiler? you only have a small volume of water entering, can only absorb so much heat before boiling... you cant get the flow rate with thermosiphon in that small a diameter to prevent boiling... a water _heater_ is most efficient when water leaves with only a very LOW temperature rise! and the flame temperature after the heat exchanger should be equal to the water temperature... all the heat being absorbed to the point that the absorber is now heating the exhaust... you should be able to put your hand over it ;) almost all the heat is being absorbed, and its heating a large amount of water a small amount. a water _boiler_ is most efficient when the water and exhaust is half the _combustion_ temperature. in this case the goal is to get the highest temperature, in the maximum amount of water. if the water/exhaust is less than half the combustion temp, you are absorbing too much, and the steam could be hotter... if its more than half, you arent absorbing enough, the water flow could be higher. youre heating less water to a higher temperature... if you wanted the highest temperature possible, equal to combustion temperature... you can only absorb a small amount. none, in fact. lots of surface area. lots of flame contact. lots of water flow. go chat up a plumber, try and get some large diameter copper pipe offcuts...(scrapyards?) 4 inch, 5 inch... cross drill the smaller piece for say, 10mm pipe, in a helical pattern... slight angle helps. you want as much flame interaction as possible, and to maintain as much water flow as possible. with as much surface area as possible.... no hot spots! bit of sheet for end caps or cough up for fabricated adaptors... if you hunt around theres even tee reducers, but they arent cheap. especially at large diameters! saves drilling holes for the inlets/outlets? solder her all up. if you dont ever get it over boiling temps, you can use soft solder... dont run it dry. for thermosiphon to work really well, you need large diameters, very easy flow path. and yeah, heat source ideally is halfway between inlet and outlet on the tank/radiator. think of convection currents in a pot of boiling water... big loops! heat, rise, cool, descend... easy! it doesnt like restricted flow... i made a small one, 28/40mm for my diesel heater? gets all that heat from the exhaust and into a big drum of water... shame its brain died last year and its almost winter again... brrr. stupid electronics. rocket stove dont need no electronics.
If its for showering, why not just have the heated water run to a seperate container so it doesnt have to mix with cold water and can be used faster? Then have a bucket that you can set in a stream or river that pulls "infinite" water to be heated. Anyhow, cool video.
To many variables to come to any kind of conclusion. The only suggestion I can make is that larger bore pipes move more water quicker, which helps up to a certain size to heat the water faster but then more fuel needs adding. So without testing lots of different variables of pipe sizes, amount of fuel added, volume of water, just accept that burning wood heats up water 👍
Enclose the reservoir so pressure can be built on the water. This will increase the boiling temperature. Remember to put an over pressure valve for safety. You could use an automotive coolant reservoir as the cap usually has one of these. I think you could reach 250f. (Also consider the volume of air in this enclose, gasses increase pressure with temperature. That's why your coolant reservoir is never filled to the brim.) The height difference implied does nothing for you since one line will benefits but the other line will equally lose energy.It is better to have short lines to your reservoir to reduce pressuredrop (increase flow). You could also increase the coil diameter slightly so there is more volume of water in the line. I expect it would be less prone to sudden boil. Keep in mind that increasing the diameter will also decrease the flow and do so conservatively.
What if you had two buckets top one to collect the hot water with a overflow into the cold bucket 🤔 that way you would get hot water not just at the top
yes. no. peltiers are fiddly. they like constant temperature, and ideal load. really hard to keep a fireplace at a constant temperature! and within rated temps, of course... i was playing around with a stove top one, got to the point of having water cooling and yeah, iunno. PC radiator i ordered got destroyed by the postie, so um... i never finished it. probably get back to it as winter draws near, lol... but was happily driving a 12v DC motor with a 12x6 prop, making a decent breeze! i think i needed four though? maybe six? did destroy plenty of modules? the colder you can keep the cold side, the harder you can run them...
@@paradiselost9946 If you had a connection to it like the water cooling blocks used in computers, you could have the cold water flow via the cold side of the peltier and the hot water on the opposite side with a block also. Then the bigger the temperature difference the more power it'll output to equalize the temp. but i'm not experienced with them and how good/poor this would operate. sounds like a fun experiment though.
@@gd.ritter thats sort of what i ended up doing? PC radiator on stand supporting fan. get up away from heat... water tank base, peltiers bolted on side. as long as theres water, its limited to 100C... i guess if one was fancy with different metals and expansion rates you could make it self regulating? just lift off the heat source when over a set temp. really want to push to 130C, maybe 150. whatever. heat block to radiator, pump. had enough power. ordered a bigger radiator and yeah.... i mentioned a destructive postie?
If I were to do anything different it would probably be that. I’m working on a video now where the copper will wrap around the outside of the chimney but I upped the side of the copper and hoses.
Just make the return pipe twice the diameter of supply pipe. As well the coils need to expand towards the top if you insist on using coils. Hot water expands. This is the reason you had it boiling and not flowing well. Don't need no stinking pump or a checkvalve, none of that crap.
Couldnt this idea be used to have on demand water like a gas burner? Like instead of accumulating warn water, consume it right away after a single pass. I wonder how much bigger of a fire we'd need for that to work.
You connected your Water Pump to your passive output line; you should connect it to your passive input line to reduce the wear on your pump and increase your thermal exchange efficiency. Cold enters the heat exchange from the bottom, not the top, you were sending cold in the top and out the bottom; you were resisting the thermal exchange and reducing how much heat you could siphon from the burning fuel as a result. You could connect the two lines closer together to increase your available thermal mass; the water is acting like a thermal battery, and the fire is replenishing that thermal battery's thermal energy, but due to how ineffective your thermal containment system is, your thermal battery is hemorrhaging thermal energy; usually, you will want insulated transport lines to reduce thermal loss, this is usually in the form of Copper Lines wrapped in Rubber or Foam, possibly with PVC pipe around that to add more insulation. The reason behind using copper lines revolves around the water reaching ~100 °C, and how effectively the material is able to withstand that temperature in extensive exposure without degrading the containment material. I understand why you used a clear line to record and scientifically diagnose your system, but I explained why those other options are used so you can understand what might happen with the system in the future, and how to fix what breaks. You do want to keep the Cold Water retrieval line lower than the hot water output line on the bucket/container side, you got that right; cold water can absorb heat easier than hot water, so grabbing from lower than the hot output line is a smart idea.
@@PatrickRemingtonmy bad. I didn’t realize you were doing experiments. As soon as I saw the pump I did indeed comment and move on. In hindsight I appreciate the efforts you went to educate folks. Maybe I’ll come back and check out some of your other stuff. Maybe. Haha. Appreciate your comment to bring me back
@@Bryan-HensleyI was trying to use this to heat a tiny home... So it will never get to 212.... Tank was stripped of insulation and painted black... The cold on the bottom never exceed 130-140 even in dead of winter with max sun could not heat enough need much more capacity of tank and panels .... But ran 6 months
It's called a gravity system we've been installing that type of system before electricity hot water goes up in the top and is the water cooled down it comes down in the bottom it's not passive it's called gravity
I made a bigger version this with the coils in the flue pipe and a pump to heat my hot tub. It worked fairly well to begin with but due to the condensation formation on the coils it got a huge buildup of soot and creosote resulting in it starting to cause a chimney fire on the coils. Luckily I had a damper to calm things down. But essentially I gave up on the idea. I might revisit it in the future and keep all coils within the fire box.
all this is interesting, but the experiment proved that if you heat this volume of water just on the fire in a metal bucket it will turn out - faster) and without these tubes, pump and so on) A, in warm weather water is perfectly heated and in any container in the sun) especially if the container black color)...
One could argue that batteries/electricity/pumps can fail at some point but whatever works for you works for you. Good thing there are multiple options for different needs.
