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Do-It-Yourself Solar Swimming Pool Heater

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Step 12: Install the glass and trim

Picture of Install the glass and trim
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).

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 if you get a chance how about digging this? Digg this
 
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mr fat10 months ago
Brilliant job! I am wondering if vertical heating pipes would work better cold water in at the bottom?
cm3stars4 years ago
Nice work! I was wondering if a modified version might have the water intake at the top of the panel, say upper left. And the outflow at the lower right. That way if you had (10) six foot pipes in your manifold the water would have a 60 foot run in the pipe instead of 10 pipes each only running six feet. I think your outflow temp would be substantially higher.
The object is to cool the collector, the longer the water is in the pipe the hotter the water AND the collector will be hotter, i.e., not cooled as well.

Like any heat exchanger the greater the temperature differential the greater the efficiency.
daveryder (author)  cm3stars4 years ago
I agree.
guynoble5 years ago
That looks like you did a really good job but a cheaper more effective option would probably be to place heat absorbers directly in the pool, such as a black thermal blanket floating on the pool surface. If you don't want to buy an expensive blanket, perhaps a couple of those large black plastic trays, intended for mixing concrete, floating on the surface. Cheap, easy to clean, stackable for storing and virtually indestructible. You could then use your solar panel for preheating water for the house instead. This way you'd be lowering your energy usage and making a difference to your fuel bills and the environment.
daveryder (author)  guynoble4 years ago
It works. You can't use pool water for your house. You worry about your bills, I'll worry about mine. All I wanted is for my family to enjoy more swimming time, and in that regard I succeeded.
leebarret4 years ago
Yeah I live in Houston Texas & I'm working on a pool cooler, since my 12,000 gallon gets too hot from july to sept! (like taking a bath) They sell pool covers for fairly cheap that will do the same thing in principle you are doing. They raise the water temp 5-10 degrees.
daveryder (author)  leebarret4 years ago
It's called a solar cover - I use that in addition to the heater - we swim one month sooner than most people around here, and one month later with the combination.

Plus, after a cold snap or rain, it heats up way faster. The whole point is getting more swimming time than you would get without the heater, and last year was a total success in that regard.

If you built one without the glass, and ran it only at night, it would work as a radiator and cool your pool down.
Utahtabby5 years ago
61 degrees still seems like FREEZING to be swimming in....In my opinion, ha! I need my pool temperature way hotter! also what is the point of using copper (other than it prevents algae) could you have used PVC or other metal, tin perhaps? I am clueless on this stuff so I am just asking, not criticizing.
daveryder (author)  Utahtabby4 years ago
Oh for sure, 61 degrees feels like ice! I like it 75+ for swimming, but it's all about getting it to heat up more quickly.
kaos2119765 years ago
This is a fantastic project. Thank you for sharing it. I have been planning something like this for my pool for some time now and this has given me a lot of good research. Mine will be 10' x 4' and be mounted on my garage roof. I will be forgoing the glass as I don't see the need in my application. I will also be using Aluminium sheeting instead of the costly copper. Copper would be better but it will be too expensive. Thanks again.
daveryder (author)  kaos2119764 years ago
I thought about putting mine on the roof, but didn't know if the pump had the pressure to raise it that high without putting a big strain on it. Plus, I didn't want to mess up my shingles with a mounting system. Plus I hate heights.
guynoble5 years ago
Your pool will adopt the mean ambient temperature. If you want to raise the temperature you must put in more heat than it is losing to the surroundings. Perhaps you should therefore think about insulating the pool sides before you expend too much effort on heating methods. Its not a difficult calculation for any first year engineering student.
daveryder (author)  guynoble4 years ago
Maybe, but the whole point is getting more swimming time, and last year proved to be a big success - see my comment above reply to leebarret.
TheCowStir5 years ago
Copper/metal is a better conductor of heat. So there will be more transfer of sun heat through the black copper pipe than there would be through pvc pipe. Plastic is more of an insulator.
Copper is the best, most cost effective, metal used to conduct heat into water. As a frame of reference, Copper rates 380.0 in conductivity whereas Aluminium is 180.0 (not bad for a common alloy) and PVC is only 0.12-0.16 (Polyvinyl). Painting the copper flat/matte black allows for more absorption as the shiny copper surface does not reflect the light energy away but rather draws it in.