homemade solar pool heating panels?

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  #1  
Old 10-17-03, 10:09 AM
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homemade solar pool heating panels?

I have a few hundred feet of 1/2" black PVC tubing that's used for drip irrigation left over from my backyard landscaping project.

Just wondering if it's worth using as a cheap home-brew solar water heater by laying the tubing and mounting it as a flat coil and running some (not all) of my filter pump output through it.

If it works, the stuff is pretty cheap to do more since the local hardware store sells 200ft rolls for about $15. 500ft rolls were a few bux more.

It might look ugly, but if it works... what the hey..
 
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  #2  
Old 10-21-03, 03:27 PM
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pools

Have tried something like that dont work to good. You cant just run the water through one line .You have to say cut it in say 25'and have them all come out of the same manifold and go to the other manifold then to the pool. I have gone to the made solar panels Have 4 4'X12' here in FL right now pool runs about 86o. Have sister out in CA. They put up 150' 1 1/2" black pvc and it worked ok ED
 
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Old 10-26-03, 05:54 PM
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Hi Ed,
may I ask you what was your original setup?

Some quick calculations yield the following:

250ft of 1/2" tubing will fit in a circular coiled area of just under 4ft diameter with approximately 10 sqft of surface area.

My pool pump, filter, heater, etc pad sits on a 4'x8' space. Two of these could fit space above my pump equipment and provide shade for the stuff at the same time.

I don't have a mechanical/fluids/thermal background, but if I'm not mistaken,
we get about 250btu/sqft/hr in bright sunlight. A dual 4ft diameter panel system should yield about ~5000btu/hr
or raise approx ~650gallons 1 degree F which isn't much in a big inground pool.

Next problem is flow capacity--each 1/2" tube is good for not many gallons per minute, so these would have to be tied in parallel as you infer. However, as long as there's enough flow to net a small temperature raise between output and input, we've achieved optimum efficiency.

And of course, for a rectangular area, 2 circles are less efficient than store-bought rectangular panels, but at $30 for 500ft of tubing, it works out to be about 1/4-1/6 the price per sq ft of area

It almost sounds like it's worth a try???

btw, this would be used in conjunction with my existing solar panels. But this would empty into the pool on a different circuit, specifically though my 3/4" fill line which never gets used unless I'm toping off the pool
 
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Old 10-27-03, 12:40 PM
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pools

Ill stay with the panels. I have tried the pipe. The best outcome is use well pvc pipe and go up to 1" or 1 1/4" black Its heaver get more heat. Also with it being bigger the water will move slower and pick up more heat.Or box the pipe in and cover it with iron free glass you get a better slolar this way
OR if you had two AC units in the home you can put another heat recovery unit on one and let the pool water go through it for hot water.This way you get free hot water and kick up the SEER of the AC unit. ED
 
  #5  
Old 11-11-03, 11:37 PM
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I think I'm going to try this out sometime in the next month or so. I don't have much to lose. If it doesn't work out, I'll just reuse the tubing for some drip irrigation I'm going to need to put in before next summer regardless :-)

Regarding the tubing--it would seem to me that the thinner the pipe the better since plastic isn't a terribly good heat conductor. The thicker wall high-pressure-rated tubing would be less efficient for heat transfer. So I bought a 500ft roll of the thin 60psi-rated stuff. My pump doesn't run anywhere close to that anyways..

I'll post some empirically derived results whether it's success or not :-)

btw--did some reading about gas-fired power plants... they get about 40-50% energy efficiency from natural gas. The rest is dumped as heat. Amazing... Too bad there's no practical way of running their hot water heat around town and into people's pools in the middle of winter instead of dumping all that heat out their cooling stacks...
 
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Old 11-12-03, 06:06 AM
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Lightbulb pools & heat

They do a lot better than 40-50% efficiency there, more like 65-70%. Then they sell that steam that made the electric for heat in other buildings. our furnaces now go up to a AFUE of 92.5%
Dont know cost there of elec. over gas . But you could put a heatpump there for the pool.
I know with the panels I can feel the water change temp just when a cloud goes over.

have a good one ED
 
  #7  
Old 06-04-04, 01:28 PM
Midbugslife
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heating for pools

Hi people Kind'A new to this but here goes. I have a swimming pool and wanted some kind of heating system in it but did not have lots of to spend on it so I went out and got 4 aquarium ( fish tank ) heaters so the pool cleaner pump would pass thrugh a smaller container which held the 4 heaters ( there for pre heating the water )then back to the pool. heaters need to be on 24/7 though and the pump needs to be on also 24/7 and the heaters had a cut off when they reach there temp it would cut off when it drops would come on. have a go it does work and only cost about 50.00
 
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Old 06-04-04, 01:54 PM
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Wink

Dont forget You get 3 times more heat for a $$ with a heat pump as you do with just a heater element.

ED
 
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