Solar Pool Heater – DIY and Cheap

Spring is here and the weather is warming up but the pool is not.  It takes until about May in this part of NW FL for the pool to get warm enough for me.  But thats way too far away when its early April currently.  The Half Ass Craftsmen came up with a plan to build a solar pool heater to speed this heating process up.  Now this isn’t a new idea but we weren’t sure how well it really worked, from what we have seen of diy solar pool heater designs on YouTube it appears to but who really knows since you can’t feel through the screen.

I wanted to spend less that $100 bucks at Lowe’s on this but Lowe’s was out of stock of one of the pieces so I got it at Home Depot.  Here’s what we bought, 1x 500ft 1/2 inch black irrigation tube (Home Depot), 1x 4×8 sheet OSB plywood, 1x 500 pack 11 inch zip ties, 5x cans of the cheapest flat black spray paint, and 2x connectors for the irrigation hose.  We did not use the connectors but got them just incase we messed up and had to cut the hose and put it back together.  We did not because we do a damn good job.

So what we want to do here is take the plywood and paint it back with the spray paint so that it will absorb more of the sun’s energy and help transfer it to the hose.  Next we spent a few minutes trying to decide the best pattern to lay out the hose on the board.  We decided to circle the entire board as you can see in the photos.  We drilled holes on either side of the tubing and ran zip ties through the board to secure the tube to the board.  Careful not to let the drill to close to the tubing, a leak would not be fun to fix.  We got close and bumped it a few times but didn’t spring a leak.  Also take care not to turn too sharp or the hose will kink and don’t zip tie in the most curved part of the turn, it will kink it.  One more caution item is to do this in direct sunlight.  We started in the shade and were keeping the tubing very close to each other but when the heat expanded it and the water pressure pushed out we had two hoses on one side bust out as to make it not a perfect coil.  I was very upset but it will still work great.

 

We took a left over 4×4 I had and cut it in half at an angle and used the two pieces as a stand to the solar pool heater to the south for the spring time sun still being a lil on the southern side.  That part totally optional but it worked well for us.  Also make sure you use good zip ties, I had a bunch in the garage of these small colored ties and they started popping when the heat and water pressure expanded the tube a little so we re ran the heavy duty black 11 inchers from Lowe’s through the ones that popped.  We saw this problem happening early on from the heat expansion so it wasn’t too bad to fix.

When all was said and done we had a solar pool heater with a long intake hose come in through a hole we drilled in the center and then coil around to a long exit tube that drains back in the pool.  For the time being I am using the pool pump jet as the source for the water but I am not going to recommend you do that because it may be too much strain for the pump.  This is 500 ft of hose remember and it has to be pumped uphill and even though I think my pump can handle it I don’t want to be responsible for yours.  Another thing is we are controlling the speed of the water by slightly kinking the exit tube putting more back pressure on the pump.  Proceed at your own risk or get a small submersible pump, you have been warned.

I have not preformed temperature readings yet because after the weekend we built it, it has literally been cloudy and raining for a week and half and is at time of writing.  On day one the water coming out was significantly warmer than the pool.  Pool was in upper 60s, the water coming out had to be in the mid 90s but will update with more accurate numbers as soon as the sun comes out.

The plan is to help heat the pool faster and being in FL there is no need for this thing for many months mid-year so it will go in the shed and hopefully be able to extend the pool season a few weeks in Oct-Nov when the first cold snaps come and the pool water starts loosing its energy.  Enjoy!