Solar Pool Heater




Introduction: Solar Pool Heater

We got a small above ground pool for the kid's and so naturally Dad decided to find a way to heat it. Solar was the first step and a wood burning heater, the second step. Following is how I built the Solar Pool Heater.

The Solar Heater works by letting the water in the black pipe heat in the sun for one hour and then pumping that water into the pool (I found this takes about ten minutes). I installed it on my garden shed roof that is East West facing with a very shallow peek so both sides get sun almost all day.

Some of the Parts I used.

1. 300 ft of black 1/2" drip irrigation pipe. (three one-hundred foot rolls)

2. 12 volt dc utility pump (the connections fit garden hose quick connectors).

3. 12 volt Battery to run the pump (i had an old gel battery for a power wheelchair).

4. 12 volt timer with 17 programmable times ( off for one hour and on for ten minutes ).

5. 12 volt battery charger ( The plan is to replace this with a solar charger ).

6. Some 1/2" copper pipe; garden quick connection fittings; 1/2" PVC pipe and fittings; pipe clamps; wire and a roll of masons line.

Step 1: Join the Pipes

I wanted a way to join the three lengths of pipe with a smooth low profile this is what I came up with.

1. I cut a 1" piece of copper pipe and pushed it into the one end of the pipe to be joined. ( I let the pipe lay in the sun to get hot so it was easier to work with).

2. I then heat up the other end of the pipe to be joined with a small hand torch and then stretched it. ( I used the 1/2" end cap on the Wire Clamp Tool, which i made in one of my other instructables).

3. I then pushed this end over other end with the copper pipe in it.

4. Now I used the Wire Clamp Tool to make a clamp Joint.

I joined all the pipe before I made the coil because I pressurized the pipe with water to be able to make a good coil and make it easier to bind with the masons line.

Step 2: Make the Coil.

1. Used a garden hose fittings and old valves I had and clamped them to the two open ends of the pipe with hose clamps.

2. Connected one valve to the water supple for the yard and ran the water till all the air was out of the pipe. Then closed the lose end and then the end connected to the water supply so I had a water filled pipe.

3. Made the coil on a hard flat surface starting in the middle with the smallest radius the pipe would make without kinking.

4. Bind the coil in eight sections with some masons line as in the photos. I tied this off, melted the ends and added a cable tie.

5. Tied both ends of the pipe to the outer edge of the coil in the same place for the connection to the pump and pool.

6. Removed the valves and used an air pump to push out all the water in the coil.

7. Put in ninety degree barbed fittings on the pipe ends so they would not kink over the edge of the shed roof.

8. Any holes I patched with some electrical rubber tape.

The empty coil was easy to lift on to the shed roof.

Step 3: Connecting Pump and Timer

1. Connected two pipes to the ninety degree barbed fittings. One to the outlet from the pump. The other to an inlet pipe I made for the pool from 1/2' PVC fittings.

2. Used plastic garden hose fitting on the pump and pool to prevent corrosion from the pool chemicals. They fit nicely into the black pipe.

3. Used an old bucket with drain hole in the bottom for the battery and timers also to keep all the cables tidy.

I ran an extension cord from a Ground-Fault Circuit Interrupters (GFCI) outlet, for safety. Also have the timer for the pool filter pump in the bucket.

The heater has been working all summer so far with out any problems and gets some heat into the pool. It's nice for day swimming but for night swimming it's still a bit cold so I added a Wood Burning Pool Heater into the system.

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    45 Discussions

    very nice !

    I used screw joints , very easy !

    screw joints.jpg

    For safety reasons, I use a 12 Volt pump, with voltaic Solar Panel.

    See and read

    Hello. Just out of curiosity I ask: Placing a plastic film black floating on the pool water would not bring a better result, avoiding losses, since the heat obtained would be immediately transferred to the water?

    3 replies

    absolutely, which is why they make black covers, but who wants to pull that on and off all the time, and pools look better when you can see the water. Pool covers essentially say: "neener neener, can't swim"

    very nice.

    I have the same pool, it has a cover that looks like bubble wrap that is meant to heat the water. it works well, but there's no regulation. if you leave it too long its unbearably hot (and of course you can't use the pool while covered *rolling eyes*). i think i might try this with a thermistor and a controller to switch the pump on and off and keep a regulated temperature (maybe a check valve too, if the pump allows water to move through it when off). kind of like a sous vide cooker (which i made recently and got the idea from)

    for night or morning swimming maybe some kind of electric heating (can run on a separate short loop with a switching valve to prevent energy loss)

    only problem is i don't have a shed and my house is 3 stories high. might need a pretty strong pump..

    Thanks for the idea.

    5 replies

    Filter pumps need to run 24/7 or else your pool turns a nice shade of green:( However I suppose you could install a switch or solenoid that can redirect the flow of the water from the pump for a few minutes to empty and fill the hose.

    Time to go to pool school or maybe actually own a pool! Not even pools in Florida need to run their pump and filter 24/7. The three main things that matter for proper daily pool pump run time are (and one of them is out of your control which causes the run time to change), and that is the actual daily high temperature. 1) one must have properly balanced pool water with the proper level of ones sanitizer of choice, 2) have a properly sized filter and pump, 3) run your pump and filter as follows:

    4 Hours 70 to 75 Degrees

    6 Hours 75 to 80 Degrees

    8 Hours 80 to 85 Degrees

    10 hours 85 to 90 Degrees

    12 Hours 90 to 95 Degrees

    14 Hours 95 to 100 Degrees

    16 Hours 100+ Degrees

    If you need to run you pump more then this then, the temperature is higher then you think, or your water is not properly balanced and sanitized, or your pump and filter are not the correct size to properly completely turn your water over once every 18 hours (best setup is 2 to 3 times in 18 hours). The filters and pumps on most above ground pools are usually the minimum to get by which forces longer run times. I am currently running my pool pump 10 hours a day and my pool water is crystal clear!

    NOTE: For pools with algae problems, eliminate Phosphates! Add the proper amount of PhosFree to your pool, then start the weekly maintenance dose of Perfect Pool w/ PhosFree.

    Pool Robot.JPG

    a pool this size doesn't need 24/7 circulation and filtration.
    public swimming pools need massive filtration but the water is not still so circulation isn't that big of a deal, however, pumping all the water takes time, that's why the pump works all the time.
    large private pools need less filtration because they are less active, but this means the water is still most of the time, once again, getting through all the water takes time.
    pools of this size take about 4 hours to filter completely. to be on the safe side, and depending on how active the pool is and the type of use, 6 to 10 hours of daily filtration is more than enough, some filter for less with great results (myself included)

    The pumps with those little pools are pretty wimpy. They are made for volume, but not pressure.

    take some instructions from inplix to learn more about it


    2 years ago

    Mami para calentar el agua

    Awesome, i made one but I live in Arizona where it gets cool at night and there are occasional clouds or shade. I also am not home does anyone here have a good source for a dawn to dusk switch or a temperature activated switch? everything i can find is a hundred or more and sized for a much larger system.

    Also ... probably loosing a lot of heat due to convection. Make edging with 2X4's then throw 2 plexiglass sheets on top, then put pipe insulation (cheap) on the pipe going to the water. Those whose systems seem really inefficient are probably in cold, perhaps breezy areas.

    Just doing the math here ... you'll have a more efficient system if continuously pumping. Efficiency goes up with a higher delta in the heating element (tube). For example ... with a heating element running at 210F getting water from 200F to 210F will take a lot longer than from 100F to 110F.

    What am I misunderstanding? How do you use drip irrigation without it leaking?

    I want to say thank you to you and other great insctructable who make me very happy. See my photo. Thank you so much, Elio from Italy


    So does this not work if the water runs continuously? Because I tried this with 160' of black garden hose running over my houses roof, but the water only came out 2 degrees warmer and after 8 hours had only gone up by 2 degrees total.