My name is Daniel Connell, I'm an open source lowtech designer. Essentially I design and tutorialise things that people can make themselves from recycled materials which allow them to generate their own energy, purify water, cook, communicate, etc. All information here is freely available for any use. If you have any questions or suggestions please send me a message.
This was dope. Thank you for explaining how it works! Once I understood the concept, I couldn't help but think about how similar this is to some of the bongs I made when I was younger lolololol
First geothermal might or might not be the best but it is an interesting idea for this scale. Second, here are some ideas of improvments: Remove the water. Use multiple thin metal rods of about 1.5m long x 3mm diameter. Coil one extremity of each rod into a flat spiral and sharpen the other one into a nail. Nail them into the ground forming a line. Only the spiral must stick out of the ground, facing each other. Encase the spirals in a pipe, sealed around the rods and blow air in it. Now also remove the pump and just use a small fan the size of the pipe. You have no pressure gradient to overcome here since there is no water. Also hot air accumulate at the top of the room so thats where you want your intake. All of that should help you improve a much simpler and better result at the cost of a little bit of metal. You can multiply the rods or increase their length for depth and coil exchange surface with the air. You could put more complexe metal structures in the ground for more exchange surface with the ground... It could really be a thing when the air/ground temperature delta is big.
I think a brtter option is a swamp cooler where you use the coold watter from the swamp cooler in a radiator in the house. I have tested a swamp cooler where in 35 C° input air the water gets down to 18 C°. This does use more power. The two fans would probably use around 150 watts of power but with a very large cooling capacity.
@@OpenSourceLowTech So mi idea is to use the water from the swamp cooler in a heat exchanger. The reson being the fact that swamp coolers can be unhealthy due to mold and other stuff. Also when a swamp cooler in high humidity it will still make the water several degrees colder so it would be a little efective regardless of humidity. The system would have a regular swamp cooler running on a roof per say, and another pump circulating the watrer in a system that has a ratiator in the house.
Two things; ! Just allow convection to do all the work for free. 2. No need to cool a body of water when the cool ground is all you need. But, yes, looks like you had some fun with this one.
A thermosiphon could potentially have been useful here, but unfortunately the ground is the cold bit, so a convection loop won't occur. Maybe if it was used for warming in winter, but there's better ways of doing that.
Seeing the air being bubbled through the water made me think of one thing: Legionair's Disease! I hope that I'm wrong about that. Being that I'm 77 years old, some of my responses are the result of a lifetime of experiences leading to wisdom and other times it's just senility. Your guess is as good as mine.😊
Water hammer is the phenomenon that happens when a gate closes the flow of water in a pipe. The momentum of that water is high and the force of it slamming on the valve is higher. Not sure how to address it Good Luck
Sir I hope you can help me with my farm In Philippines. It is bountiful of water and need free electric and water to make the farm work. With this I can give work to people ❤
@@OpenSourceLowTech yeah and it’s more rotational mass, but hey, have you ever looked into water rotor? I feel like you could make a smaller one maybe with a axle flux motor generator I know you probably have a lot on your plate, but maybe this is something to look into this is a video that you can find it on RU-vid (Waterotor Energy Technologies Development Summary) i’m going to build one but smaller maybe around 100 W they made one for about 1000 W maybe I’ll send you a prototype in the future if you’re interested or if you just wanna do it yourself that be cool
Saw those, seem potentially viable, tho I would maybe practically struggle with the submerged alternator approach, and would need to be something pretty high volting for the low rpms. But flat water generation is problem I would very much like to solve, as that's what most people have access to..
@@OpenSourceLowTech so you could use a axial flex motor, which essentially is a flat motor with a disk that the magnets go to it’s what a lot of these new wind turbines use Because they don’t have to have gearing this type of motor Allows the magnet to go faster past the rotor instead of spinning faster with gearing and what I was thinking of doing is essentially ceiling off both the rotor and the magnets separately by fiberglass over them. I can send you some pictures of kind of what I’m thinking if you want. There’s also other companies out there that Make the rotor with a printer board circuit do you have an email? I can send you some of the stuff
This is valuable work I want to test. I'm surprised that motor and pump has the strength needed. Does it work for heating in the winter ? Would it work in Florida where ground temp is not 55F but rather 72F? Does the hole remain open? You ever change the water? Does it work directly from a panel with no battery?
The backpressure is something like 0.2 psi, so doesn't take much to overcome. More than a fan impeller would handle tho.. It'll bring the air up or down to the ground temp, so if that's a useful heating range, which 72F / 22C would seem to be, then yes it'll essentially work as a heater in winter. Water vessel gets buried. Saturating it with table salt should remain sterile and not gas off, so water shouldn't need replacing. I've got another video on my channel running the pump motor directly from a PV panel. Only works in daylight obv, but that's usually the only time cooling is needed..
A fan won't be able to overcome the slight backpressure from bubbling the air through the water. But I'm also working on a heat exchanger version which might allow for it.
@@OpenSourceLowTech and there is your problem.... dont think it like a water bong. instead use coils and have the air go through the coils. running air though water is going to create a bio hazard sooner or later.
According to my calculations 192 watts demo 35 liter/s and 2.5m drop is only 22% efficient. If it was 100% efficient you should get 858w. Seams a bit low, something is very of; commercial hydropower reach over 90% efficiency, so I guess 60% might be a resonable number to expect for something like this. Either the generator is very inefficient or the impeller is inefficient or I guess both. Maybe test each one separately.
Your calculations are correct, but a 3D printed screw type impeller does a better job than the PC fan (which also does fairly ok for the accessible materials option). Pelton and Turgo type pressure turbines as used in industrial hydro power are very efficient, but require at least 20m head to operate. In low head situations such as this turbine is designed for they essentially don't operate at all, let alone efficiently.
I have designed a better system, but I don't have the land or the money to build it. It works on ONLY water being circulated. It is VERY easy to circulate water because the water going UP the pipe is balanced with the weight of the water going DOWN the pipe. This allows for a very small pump, such as the water pump from a '04 to '09 Prius 1.5 L. that pump only costs about 20 bucks. It uses 1.7 Amps at 12 volts. Thats less than 25 watts. It would work easily on ONE solar panel. Simply have a grid of copper pipes UNDER ground at least 10ft deep. Moist or wet underground dirt would work best. Then a grid of copper pipes crossing back and forth across the buildings ceiling forms the "radiator." Hot air in the building NATURALLY rises up to the ceiling.... touches the cool pipes.... and cooled air falls down. Air flow would not need a fan because air would circulate naturally. I wrote an e-book on these ideas and many more. I give my ebook to ANYONE who emails me and asks for it BY NAME. "The U.G.A.C. Underground Air Cooling." book.... here is my email address: framistan@sbcglobal.net My name is David Mundy
Cool water radiator systems are a viable approach, I tend to use air as it avoids the need for heat exchangers and zero leak plumbing, so is a bit cheaper and easier, while still doing a fairly decent job.
Yes, tho am wanting to avoid the need for large bore copper, for price reasons. Looking at non split plastic conduit pipe, which is very cheap and about 0.25mm wall thickness so does exchange heat pretty well, but my concern is the corrugations would gather condensed water from the air and potentially become little pathogen incubators. I can hopefully just have a sump outlet which drains any water, but then need to find something smooth walled so the condensation runs down.
So happy to see this project as I’ve been mulling over how to harness the plentiful thermal energy here in AZ. Rob! Not sure if you remember me, Chris, though we hung out a few years back talking music, CNC machines, alternative energy research and more. I recall spending an evening over at your place in Arcosanti to check out the projects you were working on at the time. Thanks for sharing this research and I’ll be doing a deep dive on your channel now before reaching out to see about how we can collaborate working on our many shared interests. Great work!
Rob put me (Daniel) up at Arcosanti in 2016 and helped with what I was working on there, and shot this video for me after I'd left around their continued work on the design. But not sure he'll see your comment.
Nice idea. Missing is an indicator for water level, as it will drop over time due to evaporation into the air being drawn up into the room, and a means to refill the water reservoir (could be done through the hot pipe side of the plumbing with a Y connection.
Yeah a water level would be handy, tho suspect that in a lot of conditions it should condense water out of the air and potentially eventually overflow. I've been making them with standard garden hose attachments, so you can just unclip the in and outputs, put in a dipstick, and refill if needed with water and or salt.
Swamp coolers do a good job in dry heat, but essentially stop functioning after a certain amount of humidity, and go through a lot of water when they do work. But are commonly used, and are fairly good when they're good.
Data I collected from the initial prototype (preceding this one in the video) but didn't end up in this video (but will the next): Input air temp: ~50 C (from a vacuum cleaner motor as air pump which generated a lot of heat) Ground temp: 23.5 C (~1.1m max depth, sandy above sandstone, shaded) Ambient air temp: ~30 C (both inside house and outside because bad windows and no insulation) Flow rate: 2 l/s Test time: 8.5 hours Output air temp from system: 24 C I was largely expecting the ground heat capacity to saturate at some point, but neither it or the output came hardly at all above the starting point, even running it at such high input temps for essentially the whole day. With regards to humidifying the air, even if 100% of the dumped excess heat went into vaporising the water, the result would still only be a couple percent increase in absolute humidity, and though I still need to properly test that aspect, I feel like passing warm moist air through cool water should actually dehumidify it, as that's how that is often done industrially, rather than the opposite. But remains to be seen. A closed loop system is also an option, but does introduce other potential issues. Table salt should keep the water sterile in a saturated solution and won't gas off like other options. Even extremophile organisms can't survive that level of salinity.
It's two years later any improvement or breakthroughs. Would it be possible to use rainwater we already collect and use for daily use that way the water isn't stagnant and is replenished regularly. would a fish tank bubbler work better cooling smaller bubbles
That's ingenious in the use of recycle material. However, its effectiveness at transferring the heat from the building to such a small area underground is highly questionable.
It's quite a bit more effective than I would have thought. I'll be back in Australia next year (currently in Scotland where cooling isn't such an issue) and will continue the development of this design, with actual data and outcomes.
There's just not enough internal volume and surface area to be effective. People run earth tunnels for 50 feet, or 100 feet, or 200 feet, and many setups have large diameter pipe.
Real nice Mate Cheers. You could increase your output massively by adding, 3 or more Trompe pipes in series and using all that clean free compressed air, and put your turbine on the exit? I also have an idea for a self looping Trompe almost silent air compressor, to use with the Kinetic Boyancy Genorator.
Did you hear Keppe Motors are releasing the most efficient water pump in the world? 2000L mer Min only 115w. Imagine if it used the most efficient turbine?
*All practical tests show that small wind turbines hardly generate any electricity.* Because there is hardly any wind close to the ground. Only if you need to be self-sufficient from the power grid, you should install the largest possible wind turbine on a high mast. *With solar modules, on the other hand, you can reliably generate green electricity for 25 years at approx. 3-10 cent/kWh!*
Completely uneducated guess here from a fellow kiwi but wouldnt creating laminar flow allow the fluid to impart more energy to the turbine as apposed to creating turbulence with the spin flow guide. If it works it would also have the added benefit of acting as an inline filter. I've used 100mm pvc pipe with endcap -> scotch pad -> straws -> scotch pad -> endcap to generate laminar flow for the kids to play with using a garden hose. Scotch brite pad might reduce the flow too much so a mesh might be better and plastic straws are a little bit controversial so maybe 3d print an insert instead 😂 Anyway love the content and great to see that number 8 wire mentality being spread round the world!
Oh also the issues you have with priming the test systems could be made less so by using a t fitting inline and 3d printing a simple needle / gate / ball style (albeit cylinder shaped) valve to stop flow with a fill port added either to the print or before the t fitting for filling the source tank. If 3d printing is a problem I've seen people use tyre tubes as temporary pipe plug seals with a bike pump.
Laminar flow is probably desirable, but hard to maintain through any length of pipe, even relatively straight. A straw stack would need to be at the intake so that it could be kept clean, as would definitely clog over time even with a coander filter or similar. One of the advantages of this kind of turbine over a pressure type like a Pelton is it's way more forgiving of particulates, not having a jet nozzle to clog. Not sure what you're meaning in the second comment, is about priming the siphon?
@@OpenSourceLowTech yeah, the benifits of the syphon based system is drawing from a depth so you already avoid a lot of potential blockages from surface debris. For a laminar flow stack I was thinking more of incorporating it into the turbine assembly as part of the bushing before the turbine itself but I guess it can defeat the purpose of making this as low cost and access-able as possible when adding additional complexities. If it's found to have considerable efficiency gains then it could be relatively easy to design the turbine and laminar flow stack as one insert so it's easily removed for maintenance and cleaning. The priming comment was about filling via the system itself so it's primed at the same time during filling but is only really considerable for a test rig not in production and might have issues with pump sizes. Probably more trouble than it's worth 😅. I would be really interested to see what the limits are with stacking the turbine heads within your current design (two or more fans stacked together). Kinda see if you're able to extract more energy from the water by increasing the surface area of the turbine. Times like this I wish I could do the math to figure out what the maximum possible energy for syphon given the pipe size and drop etc.
> avoid a lot of potential blockages from surface debris. Ideally, but unless it's a pretty deep pool / dam things just tend to get mixed and sucked on to your screen in fairly annoying quantities. Still need to properly test coander filters, but they'll need to be fairly large to handle the volume throughput. > can defeat the purpose of making this as low cost and access-able as possible I'm happy for there to be optional add on efficiency boosters for those with the resources, long as the baseline configuration is as universally accessible as possible. Hence the PC fan runner, tho to be fair that does turn out to do a pretty decent job.. > one insert so it's easily removed for maintenance and cleaning. Maybe, if it's a lot of extra oomph. Bit of a bugger of a process tho, and probably fairly often. > primed at the same time during filling This is more or less what I had going in Berlin, but that required a gate valve on the outlet so the water didn't just drain out. Is an option, if you can find a funnel / cone of exactly the right size to fit the gasket, as I was lucky enough to do. > interested to see what the limits are with stacking the turbine heads Yeah same. Will do some further testing on that front when I'm able. > maximum possible energy for syphon given the pipe size and drop etc. The basic equation for max system power is just flow times drop times gravity. But that gets a lot more complicated when considering pipe friction, turbulence, topology, load management, etc etc etc. I wouldn't even necessarily trust a full CFD sim, pretty much just have to build it well as you can and see what the outcomes are.
@@OpenSourceLowTech Thanks for the replies! I fortunately have all the parts in my garage to build one, joys of being a hoarder. Will definitely be playing with this concept. It's a fairly large rig to lug around for field testing so although it will add some internal turbulence I think I'll try corrugated pipe (collapsible) as for the non critical parts vs PVC lengths. Might be lucky enough to minimise the footprint to the dwc junction and 40-60cm of collapsed corrugated pipe.
