I made this solar-powered swimming pool heater out of common materials anyone could get, with ordinary tools most average homeowners have (or can borrow from friends). A friend of mine named Ace McGee (yes that’s his real name, well actually it’s Acil McGee IV) gave me a sliding glass door that was going to be thrown out from a job site he was working on (he’s a roofer, and the door had some minor cosmetic damages to the metal frame).
I decided to make it out of pressure treated 2x4s and 3/4″ plywood – the glass had leaned against my studio for over a year and you can see weeds and the weather had them filthy (wow I need to pressure wash my siding):
So the size of the collector box was dictated by the glass size (76″ x 46″). Here’s my little helper buddy Muggy (my 6 year old son) helping me lay out the copper fittings – he was a big help throughout the entire project . Also you can see part of my German Shepherd Hoppy – she was NOT a big help:
I ordered a 10′ x 20″ roll of heavy copper flashing .0216 (standard heavy weight for larger craft work, roofing and range hoods etc.) from Storm Copper Components – they are great, lowest price I could find and when I unrolled it it was almost 6″ longer than 10′ :
I cut it in half and laid the two sheets under the copper manifold I made from 1/2″ copper tubing I got from Lowes (the total copper cost in this project was around $250.00):
Then I had a hard time soldering the tubing to the flashing, the heat tended to make the flashing buckle – I screwed the tubing down tight to the flashing with metal strapping, and just did as much as I could – skipping spots when the gap got over 1/8 of an inch or so. Still I made contact with around 70% of the tubing I think:
I used my deck for part of the support, and sunk 2 4×4 posts for the other side. There is solid bedrock about 8 inches down there, so I dug big holes, used a rock hammer-drill to drill holes into the limestone at angles and put 1/2″ rebar in the bottom, which I then filled with 4 – 80lb. bags of premix concrete (we get some serious thunderstorms with strong winds):
I mounted it at a 45° angle, which may seem strange (my latitude is 38.42444) but here’s my reasoning: According to this cool sun angle calculator, that is approximately the optimum angle for me during early April and late September between 10:00AM and 11:00AM, which is when I need the heating most – during the middle of summer the water sometimes gets too warm, so maybe I’ll be able to run the system at night and radiate some excess heat.
For the supply side, I tied into the pipe going from the filter to the jet, and used 3/4″ PVC which I buried in a shallow trench (There is a tee with a drain plug at the lowest point, for winterizing):
I thought I might need a valve between the jet and the output to the heater, but it wasn’t needed – there is a lot of pressure going to the solar heater:
I painted the interior flat black, and used weather stripping between the wood strips supporting the glass and the glass instead of silicone – it’s not airtight (there are several “weepholes” drilled in the bottom for condensation). This way if I ever need to I can unscrew the trim and remove the glass easily:
I can turn it on or off with a simple valve:
The outflow is copper tubing:
Here’s the finished heater with glass installed and trim (I’m going to treat the trim and support boards with the same color stain/water seal as the decking and the collector box when the weather forecast calls for a few days of sunny warm weather):
UPDATE: Here is a little data I’ve been able to collect:
It is flowing at 3 gallons per minute (180 gph), and at 10:30AM on a sunny day the pool temp is 58° (it was 54° this morning at 8:00AM). I filled a gallon jug with water from the outflow of the solar collector (20 seconds) and the temp was nearly 61° – so it looks like on a really hot sunny day I could hope for a 4° or 5° rise in outflow temp. I think the pool is around 10,000 gallons, but trying to figure the math of it makes my brain hurt (I’m a musician, not a mathematician dammit!) and I guess it really doesn’t matter – if it works and I get even a few more days of comfortable swimming per year, then I’ll chalk this up in the WIN column
BTW there are around 50 mp3s of Dave Ryder Band music on our downloads page – all free, no strings attached.