Improved Solar Pool Heater - Full build

[@deltoncbaker]

Just thought you would like to know. Back in the 1970s, testing for the color paint that was best for the absorption of the sun's energy. The color turned out to be Forest Green. It seems Mother Nature already knew this. That is why trees are Green.

[@TheSolarPoweredEngineer]

Hi, that does make a lot of sense as the light from the sun is not truly white and the inverse of the suns colour is not black. Nature has evolved to be the most efficient form of energy receiver, you may be right, we should look at nature, it's solved a lot of issues before we came along. We assume black is it's hot to the touch but leaves are not due to the air cooling them down around them.... Hmmm, I may just try this colour on the next project. Thank you, you are the first to recommend using this colour and it makes perfect sense to me. Watch this space ;-)

[@Fatpumpumlovah2]

Incorrect heat comes from infared waves. Red captures most infared energy not green or black

[@cm8099678]

I stopped watching after only one minute, after seeing this guy using a double pane window. Use your imagination.🤣

[@TheSolarPoweredEngineer]

@@Fatpumpumlovah2 Cool, this is why I do this stuff, so I can learn while others do too. I'll have to compare different colours. So far, I have had the most success with black, but we shall see. Also, I'll be changing the glass to polycarbonate or perspex; I have a few options to try, as the double-glazed panel blocks some of those important UV and IR

[@TheSolarPoweredEngineer]

@@cm8099678 I'm still learning too, I'll be changing the glass for different materials to see if it can be more efficient.

[@nextknack]

Nice project. I made something like this 35 years ago as a school science project. Not a pool heater, just a hot water heater. I used an old car radiator, enclosed in acrylic, all painted black. It worked well.

[@TheSolarPoweredEngineer]

Thank you, it was fun to make, just need to experiment with it, I may change the glass to acrylic as the glass may be reflecting some of the energy.

[@KenWeston]

@@TheSolarPoweredEngineer I'd have thought glass a better transmitter but Uncle Google just set me straight. Might be a real measurable improvement. Neat!

[@tysondundas1947]

@@TheSolarPoweredEngineer double glazed units often have argon gas reducing UV transmission.

[@TheSolarPoweredEngineer]

@@KenWeston Google set me straight too, plus the comments here ;-).

[@TheSolarPoweredEngineer]

@@tysondundas1947 Definitely, plus it reflects some of the IR too responsible for around 50% of the heat generation. I will be looking into clear polycarbonate, both double skin and single thickness also, plus trying different paints to absorb the most amount of wavelengths (frequencies).

[@boblatkey7160]

The funnest heater my friends ever built was over 1000 feet of black irrigation pipe 3/4 of an inch in diameter. It was all coiled up in a huge pile and then they packed a massive amount of compost that was very rich in animal poop, etc., the pile of compost was probably 6 feet high and about 10 feet in diameter, then they covered it with a thin layer of clay. Once the compost started doing its thing, you could take a hot shower off of that thing for about 45 days before it finally quit! Everybody just loved it. It was called the poop shower.

[@Dreadamere1]

I truly admire your attention to detail. If you are going to do it right, do it right the first time. Respect.

[@TheSolarPoweredEngineer]

Thank you very much, total respect back to you also for noticing the detail 👍

[@SpikedaStampede]

This is the best solar water heater DIY build I've seen thus far. Thanks for sharing!

[@TheSolarPoweredEngineer]

Thank you, glad you enjoyed it 👍

[@corelockout6293]

Awesome project. Might build one myself. I used to live in south Florida and we got a ton of sun. Instead of having an electric pool heater, we had the entire back half of our roof covered in black pvc pipes, ran back and forth. Covering EVERYTHING. All one pipe, no parallel, just series. In the winter, it would keep the pool warm enough to swim in. In the summer, we had a bypass valve that would shunt the water from the input pipe, directly to the output, skipping the entire roof loop. The water coming from the jets on a sunny day would be hot-tub hot. Uncomfortably hot. 2 inch PVC if I remember. South Florida building code is designed for hurricane force winds, so roofs are built with very strong trusses, set atop concrete block exterior walls. So it can handle the load of all that water and piping. I wouldn't recommend it on an "inland" roof without consulting a professional.

[@TheSolarPoweredEngineer]

Hi, wow, that would produce a lot of heat, did you divert it to your shower and bath too? I like the idea of keeping the pool warm in the winter, I will be trying this with our pool, although know that the UK only receives around 950W/m2 of energy from the sun, plus the UK weather, so I may be asking a lot from it. My house would collapse under that much weight I think, especially if it snowed too.

[@brahmburgers]

Nice job. ....comin' from a 71 yr old semi-retired carpenter. (we don't die, we just get hammered).

[@nickcrandall6512]

I used to deliver horse feed to this race track years ago and remeber one of the Trainers bought 10x 100ft black rubber hoses from our store and hooked them all together and ran the hoses along the length on the roof of his horse stable barn. He told me that instead of using the hot water heater, he was able to get about a half hour to 45 mins of straight hot water while only taking 15mins to heat back up in between. Awesome idea dude!!!🤘

[@TheSolarPoweredEngineer]

Thank you, it's surprising that this hasn't been taken up years ago. I like the hot water for stables idea 👍

[@johnrutledge3892]

Thanks for doing this ! And sharing it . - I think glass is one of the most easily available underutilsed (by hummanity) technologies around . Im working on an air conditined green house here in the sonoran desert , It should provide both heating and cooling for the house via the sun energy and of course fresh clean organic fruit veg and possibly fish . It'll be a proud day when i sit down in my warm & or cool house with a few friends to a nice big salad , plate of fish and chips and a cold beer all produced from the sun !

[@TheSolarPoweredEngineer]

Wow, yours sounds like a great project, have you thought of making a KZbin channel on all you are doing as it would make for an interesting insight. I would certainly subscribe to you.

[@bsr8129]

lets see it, how to cool

[@TheSolarPoweredEngineer]

@@bsr8129 I should imagine this would cool the greenhouse with the panel in the shade where there is the most amount of breeze so that the passing air takes the heat away from the panel. This way you would not need the glass cover on to allow the breeze to be more effective. It would then work in reverse, cooling the greenhouse.

[@Vunderbread]

That's great, how has it turned out 2 years on?

[@TheDerperado]

I love how KZbin works when it comes to projects like this. When someone designs something amazing, instead of trying to make money by securing copyrights and preventing others from utilizing your idea, people can now share their work with everyone for free and get paid from KZbin. Everyone wins. This is what internet was designed to do, to share information.

[@TheSolarPoweredEngineer]

I love this too, I'm not fussed about getting patents as they tend to ristrict how people can use an idea without infringing on the patent. This is the same for my MGF Electric Vehicle project 😉

[@triplex7144]

This is why China takes everyone's patented ideas. They don't believe in patents as ideas can be improved upon. Sort of makes sense.

[@robertpdxusa]

Yes, still many KZbin projects are done by well trained, experienced folks or professionals and in real life it’s much more challenging, more expensive and the results differ from person to person for a variety of reasons. All this being said, I do agree with the general premise of being able to benefit from the knowledge and experience folks are willing to share here. Thank you!

[@BillyBlaze7]

My stepdad built a device like this in the 70's, we used a mirror on the inside of the box, and metal piping...it got damn hot near boiling. we were trying to get it to boiling but never made it work, our design was also pyramid shaped to gather sun from all angles

[@jamesread11]

Would be great to see some temp readout of water temp in vs out

[@TheSolarPoweredEngineer]

Hi, I will be doing some of these readings soon with a flow rate meter, in and out temperature sensors and an Arduino-based data logger that should update every second; where I now have a thermal camera too, so can also show the system in action. I will be putting all of this data on a chart to show how it performs against a purchased one and my previous homemade one.

[@TheHellis]

@@TheSolarPoweredEngineer must have had a few days of sun by now even in UK?

[@TheSolarPoweredEngineer]

@@TheHellis Hi, yes, I made a quick video with the thermal imaging camera when the pool got up to 32ºC, so will be doing some experiments in the next few days. With a full-time job and kids off school, it takes a while, but I'm getting there.

[@KA4UPW]

Agreed, And how your going to move water through it

[@Kartvillian]

Doesnt the water free flow or can use a inline 12v pump💁

[@Fatalimit]

i'm 2 years late but wow that looks beautiful and done very professionally for a diy

[@HenkaBenka]

Absolutely great video! The most efficient way to flow the water through and get the most heat out is if you make the "middle" pipe flow in the opposite direction compared to the other as it is in contact with the two adjacent pipes. So that would be, counting from "left": 1 = In, 2 = Out, 3 = In / 5 (1) = Out, 6 (2) = In, 6 (3) = Out

[@TheSolarPoweredEngineer]

Hi, thank you I will definitely try this out and get back to you with the results. This makes logical sense in my head too. I may try it one way and then the other to see the difference, although this would have to be within a close time period to get similar sun exposure, possibly over mid-day on a cloudless day. Great suggestion

[@davidepperson2376]

Great comment - can you explain why that is more efficient?

[@TheSolarPoweredEngineer]

@@davidepperson2376 Good question, I have it setup like this at the moment. I believe its due to the cooler water entering in one location and keeping that area cooler and the exit location being warmer, so mixing the ins and outs up could average the heat over the whole panel and improve its heating capacity (just off the top of my head).

[@dragoljubpetkovski8572]

@@davidepperson2376 It is not. I will try to explain these through thermodynamic processes for this case/project. The black color is a good absorber, but also is a good emitter of the heat. The only thing that matters for the good efficiency of this system is how much of the heat will be collected by the water passing through the copper pipes. The rest of the heat will be emitted into the surroundings. Heat transfer from the copper pipes into the water depends on 3 factors, the temperature difference between pipe walls and passing water which for continuous flow, in this case, is constant, surface area between pipe and water, which in this case is constant too and heat transfer coefficient that can be manipulated. The last one depends on Nusselt number, which depends on Reynolds number, which depends on the water velocity in the pipes. Higher water velocity, higher heat transfer. Since this project uses a pump for water circulation, the mass flow rate is the same throughout the whole system. Arrange pipes in parallel you divide the mass flow rate of the water by 3, which means dividing water velocity by 3 and decreasing the heat transfer coefficient. If you arrange pipes in serial, the mass flow rate will be the same, the capacity of circulating water will be the same, but water velocity will be increased, which means a higher heat transfer coefficient. I hope this was helpful.

[@brendanroberts4866]

@@dragoljubpetkovski8572 i agree with anyone who is an 'ovski'

[@dextersxxxxlab]

Saw a video some years back of a guy who also made a solar heater. He ended up with a sheet of aluminum. 1x1 mtr. On this sheet he glued aluminium c- channels with the opening to the aluminum. he did various tests with multiple glues to find the best for him and ended up with a square meter plate with a certain length of channel on it that zig zagged as one pipe over the sheet. this sheet was made black ( with my earlier mentioned sut technique in my former post). the aluminum was backed up with a foam insulator and the total put inside a frame. simple plastic foil was used to enclose it from the front. less good than your double pane glass I suppose. But this system was pretty well working to heat a pool. Made 4 if I remember well. His advantage was that the water was in direct contact with the aluminum plate and therefore pretty efficient in transfering heat. The total surface of the solar heater was facing the sun straight (when pointed at the sun) and this plate was directly heating the water. Even more effective would be to glue two square meter sheets on top of each other on the edges with a little spacer at the edge so a thin water film would be in contact with the whole surface. Then heat would not need to travel more than 1 mm to reach the water. But this did not work due to massive surface that with little water pressure would kill the glued side due to massive hydraulic forces. But as far as I remember 4 of his collectors kept the pool on temp without a problem

[@TheSolarPoweredEngineer]

That sounds something similar to what I want to achieve, I've been thinking of using my CNC machine to cut plates of aluminium into heatsinks and run water through tubing that's thermally bonded to the plates. The surface area would be greatly increased and heat transfer fairly good. I am a little worried about using different metals at the moment, especially with chlorine running through the system, I need to get a little advice first. I think the double pane glass panel is reflecting some of the energy away from the pipes, so I will have to do some experimenting this year with different materials when we get a decent summer that is.

[@faberrarius5069]

One thing to keep in mind is that copper and aluminum are dissimilar metals and will corrode if any moisture is present between them. A stainless steel sheet or regular steel plate for the heat sink backing would hold more thermal energy too

[@TheSolarPoweredEngineer]

Thank you, I am now thinking of marine grade stainless steel for the pipes and plate too, although it may be a bit pricier, but would last so much longer. I may just give it a go.

[@LabRat6619]

Of painted copper sheet, but that's expensive.

[@ch12831]

@@TheSolarPoweredEngineer Another issue is that chlorinated water is corrosive to copper pipe. Years ago, it was fairly common to use copper pipe and fittings in pool systems, but they all eventually failed due to this corrosion, while leaching cupric chloride into your pool and turning everything green. Chlorinated water is going to corrode most stainless steel as well. AL-6XN SS or Grade 2 Titanium would work well, but won't be cheap.

[@jayduffy7615]

@@ch12831 I work in the pool industry. Many manufacturers now put a zinc sacrificial anode in the water stream near the appliance (heater or whatever) to give the galvanic corrosion a place to take effect instead of on the appliance itself.

[@RangieNZ]

@faberrarius5069 The figures are off re stainless. Ali has twice the specific-heat of stainless, and 2.3 times that of copper - ali stores a huge amount of energy.

[@KipIngram]

The point of the aluminum is actually to provide a fast metal heat conduction path from everywhere the sun strikes to the pipe - to the WATER, which is where you want to get it to. You would still capture just as much sunlight without it, but if you just painted the wood black it would move much more slowly toward the water and you'd lose more of it to the outside. You're making the thermal resistance from "everywhere" to "water" as low as you can make it with the aluminum.

[@chrisfalk5578]

My grandfather built one of these in Australia 50 or 60 years ago. This was my hot water system growing up. He used copper sheeting and pipes.

[@TheSolarPoweredEngineer]

Cool, it's a shame they didn't have this platform to share their ideas, it's quite humbling to hear of what their generation created to overcome problems. Hats off to your grandfather 👍

[@Marsmate88]

Was your grandfather the founder of solahart?

[@dunno6442]

@@TheSolarPoweredEngineer makes U wonder of all the lost methods and ideas

[@TheSolarPoweredEngineer]

@@dunno6442 Definitely, at least we have the resources to share them now.

[@chrisfalk5578]

@@Marsmate88 no

[@StevieB_Slowbart]

I made a similar thing with copper pipes on copper plate. Put the inlets at the bottom and outlets at the top when the panel is tilted this creates a thermal siphon. Also rigged up a small electric pump that was driven by a solar panel. When the sun was out the pump started and if the sun went behind cloud the pump stopped. This helped to prevent spilling heat from the tank back into the collector when it was cloudy.

[@akhoneybee9076]

We did this a few years ago 🤣 only we used a black hose, the regular pool motor, some black spray paint on a fallen square aluminum road sign. It worked brilliantly for our above ground pool here in Alaska. You went crazy on this one!

[@TheSolarPoweredEngineer]

Thank you, yes I did a little, I have some more modifications to do on it too. I like the idea of using a fallen road sign, very resourceful of you 😆.

[@Dwigt_Rortugal]

"Fallen." 😉😉

[@SolarProjectsSweden]

Nice video filled with good tips & trix. I'm setting up a solar powered pool heater right now and my goal is 30°C / 86°F in the pool. I'm starting with 250 meters / 820 feet of 20 mm / ¾ inch PEM hose in a flat rooftop setup. A 20V rainwater barrel pump (2,000 liters - 528 gallons / hour) will be connected directly to a solar panel, so it's a completely automatic system controlled and powered by the sun. No sun = no pump = no heating. Since I'm located at 60° latitude in the northern hemisphere, I'll guess it'll be some problems and math to solve along the way, but it'll be fun. Keep up your good work

[@pavelschannel-alittleoutof3532]

Extremely methodical and efficient in your approach. Nicely done.

[@TheSolarPoweredEngineer]

Thank you.

[@middlesbrough123]

Might be worth baring in mind the heat generated can melt solder . It’s probably worth sticking to compression with brass olives (copper olives can leak and aren’t recommended. Great vid 👍😎

[@RandomRockets]

Wouldn't solder designed for plumbing be ok?

[@davidkuhn3970]

I like that it’s 3 separate lines, more efficient. Some people would run one long continuous line. What they don’t realize is that after a certain number of feet or meters the water doesn’t get any hotter.

[@TheSolarPoweredEngineer]

Thank you, plus the pump runs more efficiently as it has better flow, I'll need to do some more experimenting this year.

[@angrydragonslayer]

That Depends on flowrate Industrial high-pressure systems can go for several kilometers of pipe before reaching Tmax

[@fishandgameman]

Like a car radiator. A higher temp thermostat can actually reduce the coolant temperature because it slows the flow allowing more heat transfer away from the radiator. Where a fast flow wouldn’t give time to transfer the same heat before it’s getting heated again by engine heat.

[@TheSolarPoweredEngineer]

@@fishandgameman Thank you, that makes perfect sense, I guess the specific heat capacity of the material it needs to transfer the heat to would determine the ideal flow rate? Taking into account the specific heat capacity of water too. I hadn't thought of that, I suppose it's like touching a hot iron, if you touch it for a millisecond it won't transfer a lot of heat energy, but if you hold your hand there a trip to the hospital may be required :-)

[@fishandgameman]

I believe there are several variables at play that a fella could really get into the weeds over. A PWM pump motor varying flow by receiving an algorithmic processed signal of input fluid temp, coil box temp and out fluid temp would constantly adjust for optimum efficiency. A few thermistors linked to a solar powered processor of some sort and a program running would do it. The pump motor could operate on PV to since it doesn’t need to run over night anyway. I see those Arduino things, maybe that would work. You could add a circuit of pipe flowing through some sort of heat retaining material that would collect heat during the day when the sun is shining and dissipate the stored heat energy at night so you are warming the water temperature more hours per day. May need some solenoid valve and another thermistor so the algorithm can divert flow when the box coil temperature drops below the water temp at night and begins using the stored heat energy. I wouldn’t know where to begin on the software engineering part. That would be some crazy accomplishment right there.

[@yeo666]

I made 1 virtually the same as this last year. I managed to get some 10mm toughen glass 6'x3' for free on facebook so that dictated the size of my heater. Also used 10mm copper tubing but only had 2x25m rolls ( underestimated what I would need) I wanted to use same 32mm connections on my 12' intex pool so I bought a solar panel with a 8m rise pump this would result in not costing me anything to run once set up. I bought a reducer bringing it from the 32mm down into a 4x10mm outlet. I cut each Coil in half and ran 4 lengths around my board then back into connector to bring it back to 32mm to go back in the pool. I also fitted temp gauge on the outlet so I can see what the temperature is going back into the pool. It was showing a good 40-50°c going around the short lengths. After 5-7 days the 7000L pool was showing 32° with a peak of 36°. Plans this year is to get another 50m of tubing and extend each runs to 4x25m

[@TheSolarPoweredEngineer]

Hi, yeah, you'd think 50m would cover quite an area, but it runs out pretty quick. I have 75m in this one. That's some good temperature increases. I am looking to do some more experimenting this year with different configurations and materials.

[@jamesfranks5635]

Am interested in doing something similar myself. Which 8m riser pump and solar panel did you get? And also the reducer any links to that have done a search but can’t see one. Thanks

[@TheSolarPoweredEngineer]

@@jamesfranks5635 Hi, I had to have a look through old invoices to find out about the reducer, here is a link to the ones I bought: www.tradingdepot.co.uk/fitting-reducer-solder-ring-15mm-x-8mm The pump I was using was this: www.allpondsolutions.co.uk/pond/pumps/full-range/1400lh/ Although this wont pump to 8m, but Allpond may be able to help with one that does.

[@robertlappin8335]

Amazing! This is gonna be my winter project - wish me luck 🤠

[@TheSolarPoweredEngineer]

Thank you, good luck with yours, feel free to ask questions, I'm always happy to help 👍

[@jayduffy7615]

Many zip ties are not UV resistant & will become weak/brittle over time. When this happens, try using solid core copper or aluminum wire like a twist tie instead.

[@desireisfundamental]

Uv doesn't go trough glass.

[@GotMoreCakes]

@@desireisfundamentalUV-A does

[@souljunkee33]

​@@desireisfundamentaluv does go through glass.

[@MuktiadiAkhmadJanuar]

Hi! I've watched all of your videos on this topic, I also read every single comment on this video. There is tons of information and so many helpful discussion! I really interested to make one myself. Especially as I lived on the equator, I really wonder how well it can be. The last few days I already tried to make some crude experimentation with some stuff I had laying around. I had one 5 meter of 5/16" diameter hose coiled inside a 50 cm diameter alumunium wok, then I cover the wok with a 20cm glass pot lid. I use a small pump with 4 liters/s max capacity for the circulation. On midday, I fill 10 liters of water at 25°C to a bucket, then I cranked the pump to let it running at full speed. 30 minutes in, the water was already at 34°C! So based on my calcuation, it collect around 230 watt of power! Quite shockingly because basically all I just did was tossed the 5 meter hose inside the wok and top it up the with a lid without any insulation. All of this are only on 0.5 M² area. I immediately ordered 50 meters of those black pvc irigation hose for further experimentation! Anyway Its been a year since you released this video, any update for the next one? I'll looking forward it, cheers

[@Lee-San247]

Great project! The only suggestion I have is using stainless steel cable ties rather than plastic. I found out the hard way from hanging string lights outside way how the plastic ties get brittle in direct sunlight.

[@TheSolarPoweredEngineer]

Hi, yes, I do need to change them over to non-corrosive metal ones. I think this also highlights another issue reading through the comments, where the current cable ties have not degraded at all; this being an indication that the glass is reflecting/absorbing the UV instead of allowing it to pass through; this could be making the panel less efficient.

[@jeffiid5609]

Does aluminum and copper have corrosive components when they touch

[@RandomRockets]

@@jeffiid5609 Check the Galvanic Scale to find out.

[@haroldwestrich3312]

Great video and GREAT build ! ! Another note to keep in mind is that every square foot of your pool is already picking up that solar energy....so when you add a panel like this - it's only adding a tiny fraction of extra sun energy - I would guess you would need ten or more of these to raise the temp of a pool in a reasonable amount of time.

[@ET-jv1wm]

Awesome build! When we built our pool we put a bypass diversion in the filter outlet and ran it through a couple of hundred meters of piping, just under the black tiles surrounding the pool. Works like magic and supplies free hot water to raise the pool temperature.

[@thomasr1051]

Do you burn your feet on the tile? Or does the cool water cool the tile

[@ET-jv1wm]

@@thomasr1051 the tile gets hot, but just splash some water on it or step over quickly..... its about the same as a tarmac

[@TheSolarPoweredEngineer]

Nice idea, plus it's a permanent fixture so you don't have to pull it out each year and connect it all up. Would be good to have a glass floor with pipes underneath, although a bit costly.🤔

[@ET-jv1wm]

@@TheSolarPoweredEngineer That would look bloody amazing though 👏

[@ET-jv1wm]

@@TheSolarPoweredEngineer I'm only a Chippy, not an engineer.... But I was thinking that if you make a MK111 Try painting it with one of the new generation super acrylics like Musou Black. Also if you used thermal grease in between the thermal adhesive strips you would get more conductivity. Also if you add some kind of gimbal you could achieve a better angle to the sun and optimise solar aspect ratio.

[@manosdrakonakis4768]

❤..very nice design..very good work...very good result..you have respect my friend..

[@solarguy6043]

great home brew project. The copper pipe should outlast pex or other plastic pipe by a wide margin. However......it can't stand _any_ freezing. One way to reduce the risk is to program the arduino to turn the pump on if the temperature gets close to freezing inside the panel. Of course, for your application you will probably break the system down in the fall and put it away safe from freezing temperatures anyway. It's a bigger concern if you want to heat, or preheat your domestic hot water which would be a year round energy saver.

[@TheSolarPoweredEngineer]

Hi, definitely, I did think of running a small PV solar water heater when the panel got below 2 or 3º whilst isolating the pool pipes. Although, as you said, it's all packed away until the sun shows up again. I may just do a test of how it performs over the winter months, I don't mind testing things til destruction so others don't have to.

[@ffjsb]

Just add an air connection so you can blow it out before winter with a compressor. Maybe feed in a little RV antifreeze as well.

[@RandomRockets]

@@ffjsb I would either drain it and bring it inside during the winter, or use your idea to blow out the lines and add pool antifreeze. Just make it part of the pool winterizing procedure. If I wasn't so far north where the temps get -20 degrees F, and somewhere like the Carolina's, where the temps get down to about 25 degrees F, I would consider running the heater year round.

[@brianob1]

​@@RandomRocketsjust run the heating loop with a % antifreeze, say 50. You'd need a separate loop and plate exchanger so you're not getting antifreeze. Or a separate exchanger inside and blow off the heat with a fan. Just depends on your setup and applications.

[@slimel-gharbi8170]

Thank you for this sharing !!! I love it Really.... Continues this activitys....

[@kriskris3971]

great stuff. I think for the alumunium radiant layer in the bottom, it will deliver more heat if you give an airspace about 1" or 25mm where it face the alumunium layer on top of it. this way it will "harvest" any runoff heat and reflect it back into the pipes. for comparison, a solar stove of the same design with all 5 sides layered with radiant layer can go as high as 120 degrees celcius inside...very nasty heat

[@TheSolarPoweredEngineer]

Hi, thank you. That's a good idea as I was going to reduce the height of the sides to remove the amount of air between the pipes and glass, although could just move the insulating air to the back by raising the aluminium. I left this in the sun for a couple of hours when I was setting it up and the first run of water through it came out as pure steam instead for around 20 seconds, so I can quite believe it. Maybe I should make a Solar Coffee Machine 😉

[@mrz5705]

This video has prevented me from taking night school classes in thermodynamics. Thank you Neil. (consider me a subscriber)

[@TheSolarPoweredEngineer]

Your welcome, thank you for subscribing, I'm sure there will be further thermodynamic content to send you to sleep ;-)

[@mariog5569]

Nice work! If the difference of temperatures between air (outside) and water (inside) is not that large, it is hardly worth the effort to build the collector elaborately and insulate it so well. Unisolated black pipes on a flat surface do the job very well with an efficiency of about 80% and a friction of the cost. If the temperature difference is larger (e.g. hot water in winter) you will profit of this kind of construction. But respect to the nice work!

[@TheSolarPoweredEngineer]

Thank you, the idea was to take all the comments from the previous version and apply it to a new design, I will be doing further tweaks to see how efficient a home made pool heater can be and may just go back to my first design a little, where that was fairly simple and effective.

[@znpvrx]

@@TheSolarPoweredEngineer Nice project, but for a very small pool I guess. Did you measure the power output or just estimated it? With 500W of power and a 500l pool (not that big) It will take a bit over 1 hour to warm up the water by 1*C

[@TheSolarPoweredEngineer]

@@znpvrx Thank you, this is working alongside my first version that outputs around 600W on average over a good summers day (950W per square meter of solar energy mid UK) and a bubble wrap solar cover; these all heat our 4600-litre pool and has got the water to 31.7 ºC so far last week. The 500W output was calculated from the temperature difference from input to output with a measured flow rate. I have recently purchased a few flow rate meters and serial thermometers so will be making another Arduino-based data logger showing how they perform, and which one generates the most heat during a full day. The idea behind these is to see if it is possible to make an efficient water heating system at home and share my experiences. I've gone into this in quite some detail for the last version and will be doing the same for this one.

[@petersamios5409]

Nice job. I'd add a lot more insulation to the back and sides. I'd also insulate the hoses and make sure they could handle the high temps. After all of that effort, I'd prefer to waste as little heat as possible.

[@DoRC]

I think glasses from a dual pane window is a reasonable chance that it's treated to reflect at least a certain amount of The sun's energy. Most windows these days are. Just something to consider

[@TheSolarPoweredEngineer]

Thank you, I believe there is a meter that can measure this, I will look to acquire one and do some tests as I am would love to find the ultimate small form factor pool heater that is easy to make at home.

[@tonyrobinson9046]

1. Black is a lack of (none) reflected visible light. Green is visible reflected light of certain wavelengths. If green is being reflected that is more than none, so can not be more efficient. It is a bit more complicated if we consider non-visible light. 2. Standard cable-ties are not UV stabilised. After a couple of years they are likely to become brittle and may give way. 3. The double glazing is interesting. It will reflect some energy. Best is one sheet with a coating which lets the heat in but traps it. 4. I'm most interested in whether the extra effort and expense of this version was worth it. What do you think? 5. It would be easier to drill the holes into the backing sheet before you lay out the tubing, and cable tie as you go. Thank you.

[@boblatkey7160]

With a solar swimming pool heater, the higher the temperature Delta between the inlet to the panel and the outlet to the panel, the lower the efficiency. So higher flow rates and larger pipe is better. It's somewhat counterintuitive, but I learned that in solar school. so in California, for example, glazed solar panels although much hotter, are less efficient than a massive surface area of black rubber mat because the flow rates are much higher. As a rule of thumb, we would size the rubber mat array to be 75 to 100% of the surface area of the pool.

[@whosaidthat5236]

I’m using 1 inch black pipe for underground sprinklers . Lol way cheaper then copper . It is $100 for 100 feet . But I. Thinking I should now build a box to contain it . And trap heat inside.

[@feeldennis]

Dude, the measurements, the metrics to show how well it works, very interesting really. thanks

[@TheSolarPoweredEngineer]

Thank you, I will be doing more on this later in the year when the sun decides to come out. I intend to show different configurations of the pipes, comparison with my previous one and other factors that could make it more efficient. Glad you liked it

[@JulianMarinovfotografia]

Amazing! Thank you!

[@TheSolarPoweredEngineer]

Thank you.

[@RandomRockets]

Looked at several videos for this type of heater. I am extremely impressed and have chosen to use your model. Well done! Also, thank you to your commenters for their input and ideas. Have you determined how much temperature difference from input to output on a sunny day?

[@ivermectin1974]

No testing? Before and after temps?

[@anglosaxon244]

I did a similar one with the cheapest plastic hose,..and it works perfect,...maybe 90 % as good as this one in copper.

[@TheSolarPoweredEngineer]

I did make version 1 with black plastic hose and that is still working and averages around 600W during the summer months, with a mid-day max of around 900W. I will have to do some more testing this year.

[@anglosaxon244]

@@TheSolarPoweredEngineer Thank you for the answer,...there are many good ideas & inventions,everyone can make,...us humans are very capable,but the most ,preffer it the easy(and expensive)way,..in general it would be greath a more pro active actitude,...have a nice day.

[@BleachedWheat]

Coppah chewbin.

[@guidingdads]

Hahahaha

[@TheSeasonedDeveloper]

😂😂😂

[@leonlowenstadter9223]

Quite an advanced design... I build one years ago with old cans which worked fine, too - much, much cheaper, too! 🙂

[@TheSolarPoweredEngineer]

Thank you, although I like your recycling prowess much better, hats off to you

[@Krazie-Ivan]

Quite nice! Do you calculate the cost of copper tube to be worth it over your previous version? Separate smaller dia was a great thought, & I like that it avoids UV degradation concerns. Think I'd skip the sheet alum, move the air pocket from above the tubes to between the radiant insulation, & either swap to polycarbonate or make sure the glass isn't argon-filled with a low-e coating (loads of free old patio sliders here!). Really interested to see what you try/test next. Also, slightly off topic... Might consider building yourself an ICF pool, since you're not DIY shy. No reason it couldn't be above ground mostly, to avoid excavation expense. Simple long rectangle for swimming laps, insulated below, mono-pour, sealed the EcoFinish method for longevity. Continuous insulation & thermal mass would lower the requirement for heated water, plus keep temps more stable. I'm planning to put mine in a south-faced greenhouse, attached along the side of a tandem ICF garage. Should help moderate harsh winter nights in there, & the greenhouse should also protect the solar water heater from freeze (mounted to ceiling near back wall).

[@TheSolarPoweredEngineer]

Hi, the copper may be a little expensive for similar output to plastic tube, so I'm not yet convinced, apart from longer lasting, lower radius and better heat transfer, although still expensive. I have got some polycarbonate to switch to and a single pane of glass, plus some reflective foil too. My intention was to test all this out this year although I've been a little ill, but will hopefully try this out soon (ish), weather depending. I like the idea of the ICF pool for the future, although we haven't yet settled in a our own house yet, so will wait on that one. Good suggestion. Good luck with your system, it would be good to hear how you get on.

[@gladyshughes8497]

Works well, you can feel the warmer water coming back into the pool after running through the mat. Wish the inlet/outlet ports were adjustable, but overall, a good and efficient way to raise the water temp.

[@TheSolarPoweredEngineer]

Yes, these are quite surprising how much more efficient it is to heat water directly rather than use Solar derived electric heating.

[@ItsMeGiga]

Great project and fantastic build! While watching it I was thinking there might be a few improvements you could do but watching it again, I do believe you nailed it! Everything I was thinking was covered! Again great job and enjoy that pool!

[@TheSolarPoweredEngineer]

Thank you, I'm glad you enjoyed the video. There are a few improvements I would like to try, so I will capture them on video to show if they work well or not. The pool has been a nice 28 to 31ºC so far. Thank you again.

[@solarheat9016]

Nice job. Very labor intensive but effective design.

[@TheSolarPoweredEngineer]

Thank you, yes the copper was a little fun to wrestle with.

[@kevinstewart7792]

Great idea, I’ll be copying it :) but using zip ties on a project designed to sit in the sun seems like a poor choice over some bailing wire,

[@TheSolarPoweredEngineer]

Hi, thank you. I think you could be right, although survived so far the UV may destroy the plastic, the panel does stay relatively cool though with the water running through it and I thought the orange cable ties gave it a different look. Maybe bare wire twisted underneath would hold better and could be sprayed black also.

[@mtnbkr5478]

@@TheSolarPoweredEngineer Glass is UV opaque, so you don't need to worry about the zip ties in that regard. Heat may be an issue as I know that nylon printer filament only needs to reach 220-250°C to be extrudable, so if you may have steam on your hottest days, the zip ties will have probably warped.

[@TheSolarPoweredEngineer]

@@mtnbkr5478 I'll be replacing the zip ties later on and plan to use clear polycarbonate for the top and reduce the amount of air in the box, all to see how efficient a homemade pool heater can be.

[@CuthbertNibbles]

FYI, most window glass is treated to reflect IR radiation, to keep heat in your home from leaking out during the winter, and vice versa during the summer. However, it cuts off a good portion of the sun's heat for this application. If you used window glass, you may want to consider looking for some untreated glass, it should give you a huge boost, especially during cloudy weather (as IR is better than visible light at penetrating the cloud layer).

[@mastermccallbf1174]

I was wondering how the copper tubing is handling the chlorine in the pool since chlorine reacts with copper, and I wonder how long the thin copper tubing will last before seeing pinholes in the tubing. Also are you seeing any staining from the copper chloride being introduced to your pool? I currently am running a homemade solar heater, and I am always trying to re-engineer how I have it built every year trying to make it better. I have thought about copper tubing, going with very small diameter tubing running paralleled to super heat the water before reintroducing it into the water returning from the filter, so I don't have dangerously hot water spraying into the pool.

[@TheSolarPoweredEngineer]

Hi, I was concerned with this too and have done a fair amount of research to try and find answers. I have it directly connected to our pool and have not seen any corrosion, staining or any copper chloride being introduced. In England, the Drinking Water Inspectorate (DWI) requires that drinking water is maintained at the correct PH level and add 1mg/l (1 part per million) and up to 5ppm of Chlorine when carrying out maintenance; this (according to the below link - DWI Chlorine) is the safe level for drinking water within England. As this water predominantly runs through copper pipes in the home (replacing lead piping), there should be no concern with copper use concerning Chlorine as long as the PH balance is maintained. A greater PH imbalance exacerbates the issue with chlorine and copper corrosion, so it's important to keep the levels maintained. I agree that drinking water is constantly run through the home water system, where pool water is cycled around the same system, although if this is correctly maintained, there should be no concerns, especially as pool water is classed as non-potable. A good point to note with my system is that I've introduced a UVC (UV Clarifier) to our pool that allows us to reduce the Chlorine level to around 1ppm from 3ppm. I am looking at an alternative method of delivering the heat through a basic heat exchanger, so watch this space... ;-) Here is the link to the DWI Chlorine document: cdn.dwi.gov.uk/wp-content/uploads/2020/09/23151717/chlorine.pdf#:~:text=The%20World%20Health%20Organisation%20has,level%20below%201%20mg%2Fl You shouldn't get scolding hot water out of the tubes, this one has around 1.5ºC difference from input to output, this as the flow rate is around 4.5 Litres per minute which creates turbulent flow (better for heat transfer). If you run water through these at a trickle, not only will you get laminar flow (less efficient heat transfer) but you will also increase the heat out. Although this heat feels better, its the volume of heated water that counts, so a fast flowing 1.5ºC increase will make the pool warmer than a slow flowing 20ºC increase; this is because you are taking the heat away from the panel quicker and allows it more scope to heat up. I hope all that helps, please feel free to ask further questions and good luck with your system.

[@MojoMed141]

@@TheSolarPoweredEngineer ​ Have Either of you considered using a NON-Chlorine water sanitation substitute such as Pristine Blue?

[@TheSolarPoweredEngineer]

@@MojoMed141 Hi, I haven't heard of it, although know there are other alternatives to try, I did put the UVC in-line and that has drastically reduced the chlorine required to keep the pool clear and clean. I shall take a look at Pristine Blue though, Thank you for the recommendation.

[@nohemyortiz7704]

@@TheSolarPoweredEngineer iii

[@JoshuaMillerDev]

I wanted to do something like this. The changes mainly are that I would want to use alminium tubing as it transfers heat to the water very very efficiently, and second, I would want to seal it like you did enough to pull a vacuum, which in theory should force all of the energy into the water. Since I have yet to acquire a pool in life, I am sort of procrastinating. Maybe if I ever get a home I plan on staying in for longer than 2 years... even without a pool, I will try my hand at this for household hot water.

[@flip550]

But copper transfers heat better than aluminium..

[@JoshuaMillerDev]

​@@flip550 You are correct, aluminum has 60% of the heat conductivity. I wonder how that applies in a vacuum though? Also copper is roughly double the price. Would be an interesting compare in 2 identical systems.

[@601salsa]

What temp diff did it create between inflow and out? Also consider putting it on an adjustible angle 90 degrees to the sun

[@TheSolarPoweredEngineer]

Hi, I am making a 3rd version this year that tracks the sun, hopefully that will work well. I was thinking of adding mirrors that also track the sun. I need to do some more testing this year to determine the temperature difference, we didn't have much of a summer last year.

[@telocity]

My father had a construction company and so we ended up lots of leftovers from jobs. One thing we got a lot of were sliding glass patio doors and windows. Well we thought to save the windows for making our own patio. Had 4 from job and not enough for our needs and decided to store them out of the way on our low roof carport. Stacked them flat on the aluminum frames. few weeks later I happened to take a look and saw the roofing had been burned through to plywood which was black. The bottom frame was to hot to touch and the glass had warped. So stacking glass may help with heat and if you can find old single pane patio glass in frame, could be easier to work with.

[@TheSolarPoweredEngineer]

Wow, yes, that's a lot of heat build-up there. I will be trying different materials to see what works best, so watch this space. I hope the carport was recoverable.

[@jontelling]

I think a good idea would have been to open one end of the double glazing, put the coil and a blank backing sheeting inside and seal it back up. :) EDIT: you could always then put a part vacuum, improving the IR collection even more. That is, if it holds a vacuum.

[@TheSolarPoweredEngineer]

That's a great idea and makes a lot of sense, I have another double glazed unit, so may have to try that one, especially if it can take a vacuum. I will be making a 3rd version with the plastic tubing at some point this year (hopefully soon). Thank you for the suggestion 👍

[@atomisum6445]

Dude. You're a genius! I'm totally trying this with my work scrap.

[@robertpdxusa]

Personally for me the cost and efficiency are key since it really adds up every day. 😊 I use a 10 gal. container with an electric submersible heater and two small submersible pumps (out of pool & back to the pool from the 10 gal. container. It works well and fairly quickly for our needs just a small 10 ft round Intex pool. The water being pumped back to the pool is about 130 F (55 C). Total cost US$ 65 plus whatever electricity will cost.

[@marcoseduardosalesnunesdes4488]

Hi, thanks for sharing it. It was an amazing project. Please, one question. How was the increased water temperature with one set solar pool heater?

[@TheSolarPoweredEngineer]

Hi, this one is producing around 500W max at the moment (I'll be doing some modifications later to see if it can be improved), so on average over a good 8-hour day of sun it generates around 3.6kW (450W x 8hrs average), this equates to around 4ºC for 1000 litres of water or 2ºC for 2000 litres. The main issue with pool heating is in retaining the heat in the pool, where overnight it can lose a fair amount; for this I have reflective insulation around the pool, matting underneath and a pool cover that reduces evaporation also.

[@ludovicbernard4570]

Hi ! Thanks for sharing, and the comment section is full of good advices too. I’m planning on doing so on my habitable boat to get some regular hot shower.

[@TheSolarPoweredEngineer]

Hi, no dramas; yes it's getting some good responses. I will try different materials, such as Perspex, polycarbonate sheet, etc, to see how efficient they can become. Also,, it is a little heavy with the glass, so it may need these materials to make it lighter for your boat.

[@ludovicbernard4570]

I plan on contouring the boat with a black low diameter hose. I don’t know yet how far I’ll be pushing the automatism to lower the electricity consumption. I’ll see, the boat goes ashore on Tuesday !

[@TheSolarPoweredEngineer]

@@ludovicbernard4570 Ah ok, it will be interesting to hear what you have done and your results.

[@JuanAndresLanza]

Great DIY project ! Nice and tidy. Can I ask you how did you calculate the 500W ? Delta difference between water going in and water going out times water flow ?

[@TheSolarPoweredEngineer]

Hi, thank you. Yes, I measured the flow rate and calculated the wattage from the temp in to temp out. I now have some flow rate meters that I will be fitting along with accurate temperature sensors to log the performance of the solar heater.

[@nodave77]

I'm telling. I saw you measure in inches! Thanks for the video, I might try and make one for my pool.

[@TheSolarPoweredEngineer]

Haha, no way, not me... I use them only when my eyes wont focus on the cm scale ;-)

[@lionelduguay5011]

Hi Neil and congratulation on your improved Solar Pool Heater it looks really good. You mentioned a result of 500W. I am not too technically inclined so, in order to help me understand, could you tell me what temperature difference inlet/outlet did your system achieve while connected in parallel? I have a similar system with 4 boxes of 4'x4' with 30 meters of corrugated stainless steel hose in each box and I want to double up the length of hose in May 2022. Your results might persuade or dissuade me to do it. So, please let me know. Thank you so much for your reply! Lionel from Canada.

[@TheSolarPoweredEngineer]

Hi, I believe input to output was around 1 deg C from memory, although the flow was fairly high. Although, with the pipes in parallel, you can't guarantee that your getting a good flow through all the pipes, therefore series may me the best option. I will try a number of configurations this year to determine the best way. If you can configure your 4 boxes so that the connections can be adjusted, I think that will be your best option. Or even provide 4 tubes back to the pool so you can monitor flow through all. Hope that helps.

[@StormGod29]

@@TheSolarPoweredEngineer that temperature differential indicates that you are rocketing water through your panel way faster than necessary. Chemical engineers target a temperature differential (deltaT) of 10°F (5.6°C) across heat exchangers which is what this is. Select a smaller pump so you don't waste energy. Something like a MaxiJet 1200 or MaxiJet 900 is probably more than enough for this application and gets your pump energy consumption down to 20 or 10 watts. Your water in the tubes might be extremely turbulent which will decrease how much energy you transfer. You want it to be just past laminar and into the turbulent flow regime but not way into it. I can help you calculate the flow rate you need for optimal performance if you want to go down that rabbit hole.

[@TheSolarPoweredEngineer]

@@StormGod29 Good point, I assumed that the faster the water went through the more heating capacity of the system where the heating effect exponentially falls off as the heat rises towards its maximum potential. The pump is not too bad, I believe it's 24W although does make sense. I could test for the optimum flow for this one as I use a flow rate meter and accurate temperature sensors connected to an Arduino to calculate the Wattage of the system, so could run the panel for 5 mins at different flow rates over the middle of a clear day to determine the best flow, with the Arduino controlling the pump and maintaining/switching flow rates. The whole idea behind this is to see if it's possible to create a very efficient panel at home, so really appreciate your knowledge, Thank you. I may have to go down that rabbit hole.

[@StormGod29]

@@TheSolarPoweredEngineer good for you to tinker and optimize! So to expand the rabbit hole a little bit, when you absolutely rocket water down a smooth pipe you eventually get to plug flow. There is drag at the pipe walls so you get a thin region of water that kinda sticks to the inside of the pipe walls and stagnates there. In the middle (bulk fluid) you have a slug of water just shooting past that stagnant region and not interacting with it much at all. This is baaaaad for heat transfer. What you want is a very very thin laminar sublayer on the inside of the pipe and then almost the whole bulk fluid barely turbulent. This optimizes the rate you can transfer heat from the pipe wall into the bulk fluid. Fancy heat exchangers will have corrugated tubes to enhance turbulence without building a thick laminar sublayer. The more and more turbulent the flow gets, the thicker this laminar sublayer becomes and it acts as an insulator. Definitely throttling down your flow rate has the possibility of increasing your apparent power output.

[@StormGod29]

@@TheSolarPoweredEngineer also check out Tech Ingredients' videos on enhancing a solar panel using cheap mirror panels. The same results should apply equally well to flat plate thermal collectors. I've asked them to explore this but they might not or not for a while. Absolutely cheaper to fix a few mirror panels (I'd do 4) than to build another or larger thermal collector.

[@ALEX-zm1yj]

tak for din entusiasme og bidrag til alternativ energi!!!!👍

[@TheSolarPoweredEngineer]

Tak for dit svar, det er bestemt vigtigt at passe på vores planet for fremtidige generationer ;-)

[@jackonthefarm5540]

To greatly improve this, you should not use a continuous coil. You really want to use a manifold for the entrance and exit with parallel small diameter tubes connecting the manifolds. This way every tube starts with water at the current pool temp... thus the greatest heat transfer rate.

[@sleepingwarrior4618]

But don't you then have to calculate the necessary minimum lengths to gain efficiently? You could use a manifold to prevent over heating the water, essentially acting as a throttle. The problem would be on cloudy days, would the heat fail to rise enough BECAUSE it wasn't a continuous loop?

[@KenWeston]

@@sleepingwarrior4618 The greater the temperature differential between the cold and the hot, the greater the energy transfer. Might be a bit counter-intuitive but rather than, for instance, flowing water through slowly so it's nice and hot out the end you'd want it flowing faster. If you then measured the total heat gain in the swimming pool you would see that faster, less temperature rise in the output, actually heats up the pool quicker.

[@philipmariusmueller]

Just take a big watercooler, bent the cooling ribbons carefully, to maximize area and paint it deep black. Put glass on the front and thermal insulation all around and you are done :D

[@TheSolarPoweredEngineer]

Hi, this is the reason for the 3 runs in the system so it has the same (roughly) diameter as the incoming/outgoing pipe; this so that there is more surface area when in parallel and has more turbulence through the pipes with a faster flow. The turbulent flow allows all the water to contact the skin of the tubes and transfer the heat away with the colder water, where laminar flow is less efficient (similar to turbulent flow in a combustion chamber to mix fuel and oxygen to reduce hot spots (I don't see much benefit of porting and polishing intakes)). The faster you can transfer the heat away from the tubes, the more heating capacity (difference between tube surface temperature and water temperature), where thermal transfer travels from hot to cold, so with a greater difference you have more transfer. I can also reconfigure the panel to be in series to see if this would perform better on cloudy days. I like the engine analogy 😁👍

[@TheSolarPoweredEngineer]

@@sleepingwarrior4618 As long as the tubes remained as cool as possible, that would indicate the heat was being transferred to the pool. I also take the coldest water from the bottom of the pool (via the drain outlet) so that there is even more heating capacity in the system.

[@opt181]

impressed by your idea. thank you for sharing such a fabulous solar heating design

[@TheSolarPoweredEngineer]

Thank you. I may be modifying it this year to see if I can sqeeze some more energy from the sun. I believe the glass may be reflecting some of the UV and the air inside reducing its efficiency. I'm glad you liked it :-)

[@alibro7512]

Looking good. I did something similar a few years ago to heat water for the house but used silicone hose clamped between two sheets of alloy. It worked well until the wood rotted and the glass fell out. Have you calculated how efficient it is compared to using PV panels and the price difference?

[@TheSolarPoweredEngineer]

Hi, thank you, I've not yet calculated its efficiency, although it does output around 500W calculated by input to output temperature change with given flow rate, so for a panel this size (I think 0.8m squared from recollection) it's probably around 62% efficient, where PV panels are around 20% efficient, plus you would have inefficiencies in the electrical heating system also, so using PV could be as little as 15% efficient overall. Hope that answers your question, I will have to do a few tests next year. Oh and this panel cost was around £250, where 500W of PV would cost around £500, where PV tends to be around £1 per W

[@TheSolarPoweredEngineer]

@Kev Hi Kev, I wonder if I could pipe your sun over to the cold UK ;-). Yes, I've looked into making a closed-loop system using an emersion heater tank with jacket, I believe this would work really well as it's a closed system that retains the heat; would have to stop the pump and use a valve to shut off the flow though, as the panel would start to cool it if there were any water movement during the night. there is a lot less water in a bath full of water than a swimming 3m (10ft) pool too, so I'd recon you could have a free hot bath every day, especially in Southern California.

[@harrygordon2734]

We had one for our pool and we put black plastic beads in around the pipes and that improved the heat output alot

[@TheSolarPoweredEngineer]

I will have to look into different designs, I was just worried about leaks with lots of joints. Ahh, just re-read, I thought it said bends. Hmmm, beads could be an interesting idea, there is a lot more surface area. May just try this one ;-).

[@harrygordon2734]

@@TheSolarPoweredEngineer we did the same as you just looping it around

[@richardmarazzi1791]

Great project Neil, I am building one in Mexico where I live part time to heat a small pool. Have you considered reflective film inside and black pipes. Also how do you account for humidity inside the box.

[@TheSolarPoweredEngineer]

Hi Richard, the panel has 2 reflective insulation behind the aluminium plate to keep heat escaping out the back. Do you mean reflective film around the side of the box? This could help although would probably have been better with the pipes being closer to the glass, something I may have to experiment with. I hope yours goes well, should have plenty of sun in Mexico 👍

[@harunyahyadotorg]

@@TheSolarPoweredEngineer why would pipes being closer to the pipes make any difference? To one’s further away?

[@TheSolarPoweredEngineer]

@@harunyahyadotorg Hi, the pipes being closer together transfer more of the heat to adjacent pipes and will give more surface area per m2. The pipes being closer to the glass (or acrylic) would reduce the amount of air between and would reduce the shadow from the edges so more sun could get in. The air also has a specific heat capacity and some of the sun's energy would be taken by this layer (hence the efficiency of an evacuated tube solar heater).

[@no-damn-alias]

You get much more power in the same area with some solar panels and a pool heat pump. They usually have a cop of 6. So 850w will give you more than 5kw of heating. 850w are two big solar panels which are dirt cheap. When I google for pool heat pumps, they're fairly cheap as well. Also when you don't use the heat pump the solar panels will set off some of your electricity bill

[@KipIngram]

Yeah, I've thought some about this, and in every way except pump power it seems that the faster you can move the water through the better. You're getting a fixed amount of energy into your collector, and you want it OUT into your water as fast as possible - doing it slower means more temperature rise in the collector and that means more loss to the outside.

[@LabRat6619]

Your pipework will be very prone to blocking with inevitable debris from the pool. Also when water/coolant gets extremely hot it can turn to steam if its at normal atmospheric pressure, this will stop all water flowing through. Sorry if this sounds negative, but I'm a heating engineer.

[@mikaelericsson2491]

STUNNING! Your video is perfect! That was the best instruction video I ever seen on KZbin.

[@TheSolarPoweredEngineer]

Thank you 😊

[@ehombane]

Thanks for providing the most important information. Production. I use an electric boiler. And average daily consumption is 2Kwh. So in similar insolation I would need four times that surface. Maybe here is a little more sunnier, but trees and west orientation of my facade will make this not feasible.

[@TheSolarPoweredEngineer]

No worries. When testing this and a previous version, I was impressed by the efficiency of directly heating water, you could easily heat a tank of water with one of these for a daily shower; well, in the summer anyway (UK).

[@CB-jc6vb]

One thing i noticed that will make a difference if you can put it on roof shingles or metal roof get hot better than a box on ground or stand will make a difference not sure how much

[@stuartwakefield1657]

Hi Neil, great job and very helpful. When I build mine I used black corrugated plastic pipe. The other thing I did was to angle the panel so it faced the Sun. Stuart

[@TheSolarPoweredEngineer]

Hi, thank you, yes angling the panel would get the most out of the sun. This panel is fairly heavy, so I have some mirrored acrylic to attach to the sides, where I will automate the angles of both panels to direct the energy to the panel. I hope yours is working well. Glad this video was helpful.

[@stuartwakefield1657]

@@TheSolarPoweredEngineer reflection the sun does work very well. My unit is the same as your and it's strapped to a 4 wheel porters trolley. We are moving from the Midlands to Cornwall soon so it will work even better.

[@TheSolarPoweredEngineer]

@@stuartwakefield1657 That's an excellent way to move it around; we live in the midlands too, although initially from Southend. Cornwall should help with the panel, especially if you have a south-facing garden. I do like Cornwall; I would recommend the Minac Theatre on the way down to Lands End.

[@davidcurle7381]

Doing any tubing heater is to start in the centre with cross piece, and using the two tubws in oposite direction work your way out to the edge that way you end up with the two ends coming out the side instead of having to cross across the top of the other pipes.

[@atomisum6445]

Working with commercial glass. Have a rack of units stacked in the sun on a mild sunny fall day can get so hot it breaks the 4th or fifth one in the stack but the first one is always cool to the touch.

[@TheSolarPoweredEngineer]

H'mmm that's some good observations there, this heat could be harnest and a at the same time save the commercial glass from cracking. They could store it in the sun intentionally on racks with water pipes running between to collect the heat. Maybe the staff could then get free showers at work and save on their own bills ;-)

[@textheflex881]

Excellent job mate, I look forward to trying my hand at one myself. Cheers!

[@pinnaclemans99]

Black & orange. I agree those are great colors. Who Dey - Go Bengals in the SuperBowl

[@TheSolarPoweredEngineer]

Thank you, maybe I should do a Bengals tribute pool heater 😉

[@jec_ecart]

Good project. Copper pipe heaters were common in India 2 decades ago. Now no one uses them because pipes will corrode or choke due to calcium. Now everyone uses vacuum tube heaters.

[@TheSolarPoweredEngineer]

Thank you, it was fun to make and even better to have a warm pool. I haven't noticed any yet, although it is still early days. I wasn't sure about vacuum tubes as they seem fairly expensive for just heating a pool, although could be used for both home and pool I guess.

[@artblummer5307]

Excellent design and implementation! Very professional appearance and product ! Well done !!!

[@TheSolarPoweredEngineer]

Thank you very much, hopefully more to come.

[@tazsnoop1044]

Nice work, as a plumber I see a problem with the way it's hooked up it needs a manifold with were the flow of water would be evenly distributed through each copper coil

[@KipIngram]

What would be "ideal" would be to solder or braze the tubing down to the aluminum along its entire length, but wow, that would be quite a job with 75m of tubing. You used a lot of tape, though, so that's probably pretty good.

[@robertdominiczak6523]

There is no way that would heat my pool , but it’s a superb build. I do have a big pool .

[@TheSolarPoweredEngineer]

Thank you, it is small for most big pools, although the concept could work, I'm looking into the most efficient version that people can make at home, although finding out that copper may not be the best for chlorine in the pool if the PH is off, more info required on that one.

[@unionse7en]

people if you want to build one of these you can use far less copper, I use an old thermal solar panel to heat my hot tubs. it uses parallel rows of 3/4" copper spaces about 4-5" apart all connected to a 3/4" manifold pipe at the small ends. Works incredibly well. In colorado (sunny) if water is not moving it will boil off all the water inside it of the water is not circulated for around 5 minutes (many variables but it gives you an idea). The sun "insolation" value is approx 1000 watts/m2 , direct solar thermal can convert almost all of that...vs photovoltaic panels at approx 20% efficiency....BUT if you run a heat pump with that operating at a COP of 3-5x.... it's kind of a wash.... One might also have to build an automated control system to shade the thermal panel when you have reached a target temp to avoid stressing the water panel ...can't just stop the pump as the water will boil off and then the panel temp gets very hot...lots of stress from thermal expansion etc..... of course freezing climates are an issue ... there are ways around it but DIY PV is at it's cheapest right now by a far bit. Use a bit of each system I say!

[@andrasbradacs6016]

Next time you should try BLK3.0 as the paint. It’s much darker then a normal black, maybe it can observe more heat as well. And maybe the copper tubing could be closed into an own housing and that housing could be closed into the bigger one. Pumping out the air making vacuum between the two housing can make it much more efficient because you will not lose any heat on the copper pipes.

[@faridjahed]

Can't stop watching your video

[@TheSolarPoweredEngineer]

Thank you.

[@luishenriquerotermundkreis5849]

you can mirrors all around to reflect the more sun light thus improving the heat efficiency!

[@TheSolarPoweredEngineer]

Hi, yes, this should work well where I have a couple of Perspex sheets with mirror surface on the front (no refraction from within the substrate) that I will be trying out. The intention is to track the sun throughout the day by controlling the angle of the mirrors. Perspex is fairly light too so should not need too much power to operate.

[@michaelrogers8460]

Out standing job. I am impressed .

[@TheSolarPoweredEngineer]

Thank you.

[@bucky5063]

Great job looks amazing

[@TheSolarPoweredEngineer]

Thank you.

[@Pabz2030]

Maths is your friend here. Maximum available solar insolation per square meter based on latitude and time of year means there is a limit on the maximum energy you can extract for any given surface area. You will never extract 100% of the available energy due to loses etc. The max insolation for 50 deg north at solar noon in mid summer is 1kW (1000 watts) per sq meter at an incidence angle of 90 degrees The energy required to heat 1 liter of water 1 deg C is 1000 calories. 1 watt is 0.24 calories per second (watts are a measure of power over time), so 1000 watts will raise 1 liter of water 1deg C in about 4 seconds. Which means that on June 21st in the UK between 12.30pm and 1.30pm (solar noon) you can heat as an absolute maximum 900 liters of water 1 deg C, or 90 liters of water 10 deg C for every 1 sq meter of solar collector surface area. In reality due to losses etc this will actually only be about 60% of maximum, equating to about 50 liters of water heated by 10 Deg C for every Sq meter of solar collector for one hour at the middle of the day in the middle of summer. Outside of this it falls off quite rapidly, both in terms of time of day and time of year. If you had a cloudless day you would effectively collect about 6 kW energy per sq meter over the entire day at 50 deg north on June 21st, and about 2kW per sq meter in mid winter if you dual track the sun. An average swimming pool is about 2 meters by 2 meters by 5 meters or about 20,000 liters, will require roughly 400 sq meters of surface area of solar collector to be heated by 10C in the middle of the day in the middle of summer in the UK, or about 80sq meters of collector if you happen to have a cloudless day and the panels are solar tracked. If you want to heat the water to bath like temps, time to cover an area about 20 meters by 50 meters with panels and then make sure to prevent heat loss a night. You are actually better off using solar PV and powering an electric heater. Good luck.

[@TheSolarPoweredEngineer]

Hi, that sounds fair, although not sure about the PV panels and heating with electric due to PV only being around 20% efficient and Solar Thermal (ST) around 60% efficient, also with the direct heating of water from ST as opposed to Power losses through PV cables, each connector, charge controller power consumption, battery charging inefficiency (especially lead acid) and heating element to name a few. Although, that said, you could collect energy from PV over a number of weeks and then only heat the pool when necessary so you could have a smaller system. We did manage to get our 3m diameter pool up to 31deg C in summer of 2020 over the course of 7 days from around 22deg, and that was using my first homemade panel that produced on average 600W per day (4.8KWh), 900W max during midday. We had heat loss of around 1 to 3 over night as we had the pool covered and wrapped in reflective bubble wrap, so that helped a lot. All the calculations for the specific heat capacity of water (just below 4200), the amount of water (4600 litres) and joules produced by the panels calculated correctly to what we were seeing. I've learned a lot from making this system and love the answers in the comments section, they are thought provoking and help think about other solutions, thank you. What do you think on ground source heat, I was thinking of combining a number of systems for an all year round pool heater that would not freeze due to the ground source and possibly air heat exchanger tied in together?

[@Pabz2030]

@@TheSolarPoweredEngineer Sorry the Pv comment was meant to be a bit tongue in cheek... but in terms of cost, maintenance etc, it is actually more cost effective over time to use Pv and an immersion heater if you have the space for a lot of Pv panels. I really enjoyed you vid by the way... i´m a bit of a solar geek and have put together a number of systems myself (water and Pv) over the years and really enjoy seeing other peoples adventures in it. We used to live in wales and had ground source heat pump with about half a mile of buried pipe in a field, and it was pretty effective even in deep wet welsh winters. The heat pump itself used a fair amount of power so I would advise pairing it with a good Pv system or the electric bill can be a bit of a surprise. These days I live in Spain so have the luxury of a lot of sun and a enough land ofr a sizeable ground mount Pv array. (but no pool ironically). I have messed with making a solar heat collector for hot water here, but with the sun and space it just came down to Pv and an immersion heater being a better alternative in this location. I think your notion of combining sytems is actually probably the best (and most fun to design/make)...so if you have the space a Ground source pump powered by PV with solar collectors for additional capacity would be pretty awesome.. I would definitely like to see that put together. Oh subbed by the way, just in case ... :)

[@TheSolarPoweredEngineer]

@@Pabz2030 Hi, thank you, no dramas at all, I love to respond to all the comments, especially when it's engineering, I still teach electronics and valve theory to some degree strangely, so it's nice to chat to someone in the know. I've been thinking of a number of things along combining solar systems, such as, using Solar Thermal to heat an emersion tank of water to directly feed into a washing machin and/or dishwasher and just use PV for running the machine and spinning the drum/pumping water. I think this would be much more efficient. I'm also converting a car to electric and converting my mill to CNC that's run by solar, so essentially the car is being manufactured using solar also. It's amazing what can be achieved today in a home garage and am enjoying the learning journey. Glad you liked the video, plenty more to come and thank you for subscribing 👍.

[@igor2030ign]

Very nice build. And you forget to mention the cost: 2 million dollars and 1000 years to build it. More cheeper to use PVC hose or pipes. Anyway the concept is quite good! Thanks

[@TheSolarPoweredEngineer]

Hi, thank you. In that case, this one is very cheap at only a fraction of the cost and time to build. This would most likely cost around £300 to £350 in todays prices, although cost me around £250, but just to try it all out, I will be doing some modifications soon to see if it can get more efficient and cheaper to make. I did create a version 1 system with PVC piping and that one works well, although its fairly cumbersome to move around.

[@igor2030ign]

@@TheSolarPoweredEngineer oh, great. Never view the pvc pipe version. Thanks for share and reply!

[@TheSolarPoweredEngineer]

@@igor2030ign No dramas 👍

[@superpuppy7854]

You said that you wanted to eliminate the possibility of leaks inside the frame but then you embedded the Yorkshire joints you'd soldered into the frame. Perhaps it would have been better to add a few inches to the length of the frame to create an area where you could fashion a manifold for the pipes. Another advantage of that would be that you would only have one feed and a return connection outside of the frame. Looks nice!

[@TheSolarPoweredEngineer]

Hi, very true, I considered the soldered joints to be permanent and not leak, although these could leak especially with a lot of movement with the outside connections going on and off. They don't take too long to fix tough. I wanted to have the ability to change configuration and test flow rates and different in to out, just to see if there is any difference feeding water directly to the middle or the outside. Thank you. Glad you enjoyed it 👍

[@giannisf]

Hello from Athens Greece it was amazing video, excellent, thanks. I don't say anything very good job

[@TheSolarPoweredEngineer]

Hello from the UK, and thank you for your kind words.

[@freddiegraham4756]

You would see a significant temp increase by bringing the pipes no more than 6mm away from glass. I would also be using sand on my backboard before painting to reduce the risk of rays bouncing straight out the box. Try it. You will notice a big temp increase in low, weak sunshine.

[@spocksvulcanbrain]

My only suggestion is a few small air holes. You've sealed it up so well that on a really sunny day, the air inside might expand too rapidly for it to dissipate through the cracks. This might dislodge the glass top. A few 1/8 inch holes on each side would prevent that yet still keep out bugs, dirt, etc. In a really sunny place like Florida, this would be a real possibility.

[@TheSolarPoweredEngineer]

Hi, yes I have already experienced the sealant splitting and will be putting a few small holes in it, plus doing some more modifications too. This one is producing around 500W so far, but I'm sure this can be doubled, we get around 1000W per m2 so should be able to achieve this with different materials and a couple of acrylic sun tracking side mirrors ;-)

[@spocksvulcanbrain]

@@TheSolarPoweredEngineer Cool. I'd be interested to know how hot the water comes out on different days based on cloud cover. Also if you're recirculating it or just heating up from original source. Keep the project ideas coming.

[@TheSolarPoweredEngineer]

@@spocksvulcanbrain Thank you, I will be doing a video on cloudy days too, especially after the mirrors are attached. I'll try