DIY Solar Pool Heater with Full Automation Control - Complete Build 

Excellent build!

Some fairly simple pressure drop calculations at various flow rates would minimize all the rework that you’re doing mostly by guessing. You will find larger tubing makes very big difference in reducing pressure drop. Also, once you know the pressure drop across your heater you will know how big the difference is between the “normal “ flow path and through the heater. I think a booster pump for the heater loop would give you more control over heater flow rate.

Great video thanks a lot

What’s the highest temperature you have been able to reach with this new solar system? Thanks

😂😂❤❤ difficult job looks easy bro .i wants to do your project.

just FYI, not all PEX is UV rated. I would hope Vevor knew what you were using it for and gave you some UV rated PEX. Even then, I would not like to have any PEX exposed to the sun all the time. Not sure what paint you used, but latex paint gives a UV barrier that protects the PEX, not sure if regular spray paint does or not. Maybe use a layer of black polyethylene between the PEEX and the polycarbonate cover you put on top? To make it even worse, PEX when exposed to UV and chlorinated water can cause it to deteriorate even faster.

29:27 no tee for temperature control, using the waterfall for cooling. Excellent plumbing.

If you can report the flow rate and temperature rise of the water going through the heater, that would be a great comparison for other heating methods, and it would make it possible to see the real impact of this and similar systems on a pool

We want to see how you connected the tubing to your pump and back to the pool do a video on that

Seat of the pants engineering at it's best.

Nice build! Looking forward to seeing how it performs with the polycarbonate. I need to add a water temp sensor to my pool setup. How do you keep the hole sealed?

Hi Chris, do you think the black pe tube or the red pex tube is better for the system? Thank you.

Have you checked you get reliable and even flow through all 4 panels given that you allow air in for it to drain down when turned off? I've got 5 panels very similar to yours, 1.7m x 1m each, around 75m of black irrigation per panel and glass covered on my garage roof, mine are connected together using irrigation hose fittings and although I have no visible leaks I must have a small one somewhere as I get air in the system overnight when it's turned off which can then lead to a panel getting an air lock and not flowing anything when it powers back up needing to force water through it individually to clear it. I'm only running it with a relatively small pond pump rather than via the main pool pump though, so a big pump with more flow and pressure might clear the air better. Regarding automation, other than setting a target pool temperature to decide when the valve opens do you control when the panels are active or bypassed, for example if you're running the filter after the sun has gone down or when there's bad weather? Being in the UK we get far more unpredictable summer weather than you do so I probably need to pay closer attention to automating that side of the control because I've found if I run the panels when it's really overcast or raining or at night they will actually have a cooling effect on the water returning it a couple of degrees below what came out of the pool. The way I've done my automation is with a temperature sensor in the pool, one in the solar panel water return and also one measuring the air temp inside a panel. I control it all using Home Assistant triggering the pump to start whenever the panel air temperature is 5c above pool water temp which seems to be about right to get an overall gain, it then monitors the return flow temperature and shuts off when that temperature is equal or lower than the pool temp. That all works really well to run it whenever there's heat to be gained and prevent any running when it would be actually cooling the pool. Finally do you know what the flow rate is through the system? If you know that and you know the temperature delta between pool and the returning water then you can work out the kW output of the panels and compare them against conventional pool heaters. My pump gives me ~600L/hr flow through the panels and I get around 6-7c uplift in returning water temperature on a warm UK day (23-25c and sunny), which equates to around 4kW of energy which I don't think is too bad at all effectively for free.

1/2" pex tubing is the same ID as 3/8 copper pipe. 3/4" pex is closer to 1/2" copper pipe. 3/4" pex should be 5/8" ID. So definitely very restricting. Thanks for the video!

Do you think it will work to heat up a large pool durning winter? I mean to get it up to let’s say 85 degrees? I live in Florida so winter will be about 65-70 degrees weather

Helo, you dont have flow problems using 4x 1/2 pex? I calculate that I should use 4x 3/4 pex (or 9x 1/2 pex tube) to have the same water flow of 1x 1 1/2 tube.

What iphone app is tracking temperature? Is it home assistant or something proprietary?

Are you relying on the polycarbonate to eliminate UV destruction of that pex, or does the paint provide that protection? Also wondering about chlorine’s effect on the pex. I have a salt system and if I implemented something like this I wonder if I’d need it to precede the cell.

Are the zip ties UV rated? I see so much UV damage on some but not all plastic parts. The Florida sun here is really tough on plastic parts.

I'm confused, you say this latest system is the best, but it's only pumping out 1 or 2 degrees above input whereas version one was steaming in your bucket! at over 110!

Would slowing the flow rate through your solar panels increase water temp?

Any reason why you wouldn't use an underfloor heating tray to secure the PEX piping in position? Cost & space maybe?

I wonder if the holes in your roof will leak?

Can i know why you didnt close the surface of your solar water heater with glass ? As far as i know moat company that make it cover its surface with glass

Pex or irrigation hose? I thought pex but the comments are making me second guess the SoCal UV rays.

Is that a crack in the top of that T at 41:42?

I 🤔 you are getting a bunch of heat loss by not having the panels covered ti keep airflow off the tubing. Can you cover and retest to show the difference for us?

Is that UV resistant PEX?

What pool controller is that?

I have been thinking about making a similar setup for a basic paddling pool heater and even made a basic spiral out of black garden hose. Works very well and was getting some good hot water. Expanding your idea though I would look at running a separate pump to the pipe on the roof to run the water slowly through the system. Perhaps even a small tank to keep the loop up top always full of water so you weren't putting the pumps under too much load. The other thought would be to stop flow over night so you weren't loosing heat in the loop too.

Instead of using square tube (which looks like a stolen stop sign stand). Why not use solar panel brackets to attach it to the roof?

How many gallons of water in your pool?

What was wrong with build 3?

Temperature difference is meaningless without knowing the flow rate. A candle flame will burn you but take a million years to heat a pool! Temperature is only one axis of energy content of a substance - need volume and specific heat capacity too! Based on insolation of 1kW per square meter and guess 80% heat collection efficiency, then with a 3.5 x 2 m roof, that should give a rough peak of 7kW x 80% = 5.6 kW. Assuming no shade, Integrating 8 x 3kW over a day could yield about 24 kWh. This is enough to raise temp of 16,000 US gallons by 0.6 °F, or 60 tonnes by 0.33 °C per day. Sounds comparable to your results.

Pex pipe is not solar ray safe.

Curious why not just paint a section of the pool floor black? That requires no piping or pumping, and is always available for heating the water?

You'd increase your heat gain exponentially by connecting all your coils in series so flow has to travel all 1000 ft

I appreciate you making the video, but I've got a question (this is for 3rd party viewers). Why did you use 1.5" downstream of the panels? If you're feeding the panels from 2", I would have thought you'd want 2" on the return. I know you recognized the (4) 1/2" pex panels were causing a restriction, so you put the bypass in, but you're bypassing back to the undersized 1.5" return, so while you may be mitigating one source of restriction, you're still choking your pump. By the way, PSI on your filter is bad. It is resistance to flow. Ideally you want as low a PSI as possible.

With 100 deg I think you don't need the solar heater at all

I have always been sceptical about these DIY solar pool heater projects and their effectiveness...so I built one. 300 feet of irrigation hose coiled in a rectangular loop in a black tray. Small fountain pump for the flow through of water. Panel aligned due north and permamently unshaded. RESULT AND CONCLUSSIONS A great way to cool down 300 feet of irrigation tube to match the temperature of the incoming water. A very inefficient way to warm up 40,000 litres of water to any degree over any amount of time. ie no gain. A huge waste of irrigation tube better used for...irrigation. My scepticism....Confirmed.