Solar Would you do it again/Is it all that they advertise?

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Just an FYI, the sun only puts out about 300 BTU/sq-ft/hr at normal incidence and at high noon. So even at 100% efficiency, it would be impossible to get 30,000 BTU/hr with only 42 sq-ft of capture area. I think your temperature differential measurements may be incorrect.
 
Regarding one year warranties, get it installed in say, June, so you have basically two summers for something to go wrong. I had mine removed and reinstalled when doing a roof. Year one June - March - OK. Turned it on to test it in April, it leaked. Got him out to fix it. Think strategically.
 
If you were referring to mine, I stand by my measurements, I get a 3 - 4 degree temp change from 10:30am - 4pm at 15 gallons per minute. You're sq ft looks too small. In any event I have 1000' of 1/2" tubing on 2 systems, and then another "experimental" one that consists of 300' of 1" PVC painted black. I have perfect south exposure. The roof temp during these times is around 140 degrees which Im sure adds to the water temp via transfer from the roof. Generally I'm getting a water temperature change in my 8000 gallon pool of 3 degrees a day when its sunny. Everything has been measured with digital cooper instruments which I have reading the pool water and solar output back into the pool. I see it in action every day, and the pool water temp speaks for itself. That being said......I lost nearly 9 degrees in 4 days with no sun and constant rain...tomorrow its clear again and I am positive that my pool will be back into the low 80s by the weekend. heating from sun exposure I am sure adds a bit, but not much because the pool has a lot of shade from palm trees. Air temps are still int he upper 70s, with nights in the 60s.

Take out the "infrasturcture" that you would have to pay for regardless what system you install, and the cost to do what I did was negligible. Might not be as good as some of the other pro systems out there, but its close enough, and frankly its not going to blow off like many of those strap down systems, especially in tropical climates like mine.
 
My solar panels typically add 6-9° degrees during the day and I lose 3-5° of that overnight with with no cover for a net 24 temp differential of 3-4° increase. My panels are in partial shade and my pool is in partial shade. I have an 8mil, clear solar cover sitting in a box waiting for me and a pair of scissors. I am waiting for the trees to stop assaulting my pool before I put the cover on.
 
rick999 said:
If you were referring to mine, I stand by my measurements, I get a 3 - 4 degree temp change from 10:30am - 4pm at 15 gallons per minute.
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If you are talking about the pool water temperature change, I get that without solar running at all so that isn't saying anything.

If you are talking about an input to output panel water temperature change, the fact is you cannot gain more heat than the sun puts out. That violates the laws of physics. If your temp measurements are correct, then perhaps your flow rate measurement is incorrect. If you bypass any part of your normal plumbing to measure the flow rate, then you are changing the pump head loss which artificially increases the flow rate so your measurement will not be correct.

Also because the angle of incidence of the sun hitting the panels changes with time of day, the BTU gain of the panels will also change as a function of time of day. So you will not see a constant heat gain delta (panel in to out) over the entire day.

So what you are describing is simply not possible.
 
As I said many times in the past, I sometimes under optimal conditions get a single degree in temp change on a sunny day in March. I am about 45 percent shaded, and I DO NOT use a pool cover at all....only during winter to keep leaves out.

I think I know how to measure water temperature. WHen I turn on the solar I turn off the skimmer and pull from the deep end drain. I measure the pool temp.....Ive never found it to be a different temp in any place, it is consistent all around. The water goes to the pump and I have a valve after the filter that sends it to the roof through the 2 coils and the 300' of pvc and it returns DIRECTLY from the roof and over the side of the pool (temporary setup). So it is quite easy to measure the temperature. I said that there is a temp difference of 3 - 4 degrees during the day....to answer your comment about not being constant....that is correct...I dont turn it on until 10:30 when the sun is already quite high in the sky......after the 135 degree water flushes out,.....it settles in around 3 degrees difference....it then builds as the sun gets higher to around 4 degrees, When it reaches that point I usually open the valve up full on the 1" PVC to increase the flow and it goes from 4 degrees to 3 degrees and that is when I am getting 15 gallons per minute. Ive times it several times filling a 5 gallon pail in 19 seconds. THat makes it 15 gallons per minute.

Uhhh...its not rocket science dude...and I have a science background...so all I can tell you is what I put up, and what I am getting. You say its impossible but Im here seeing it first hand . 3 or 4 degree temperature change mathematically equates nearly precisely to the rise in temp per day of the 8000 pool on a sunny day.

I did this because I built something like this when I was 13 years old for one of my science fairs. Its not complex and it works. No need to invest thousands of dollars and I'm not the first, you just need to google Solar Collector for Pools and you will come up with all kinds of great ideas that work.

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pabeader

YES......I was getting 1 degree under optimum conditions.....hot day...clear sky. Again...I am about 45 % shaded. This was EXACTLY why I built this, because I didnt want to wait another month to use the pool

Having said that, the pool temp increase due to the sun has nothing to do with the fact that I get a 4 degree temp change water in/water out.

When I get a chance I will video this and post it. I want you to see the crystal clear evidence....not for my sake but for others who might want to try it themselves. The results are undeniable and you can google this and see lots of other people who get similar results.

As an interesting note.....even on a lightly overcast day, I will see a 1 degree temp change just from the radiant energy on the roof. I've measured the roof temp and its around 98 degrees on overcast days, so its interesting to see how radiant energy gets absorbed. As I said in the past, I am sure that radiant energy is also playing a role in temperature output. On a clear day the roof is over a 140 degrees.
 

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Here are two photos I just took. one is the pool temp in the deep section where I draw from. When using the solar I close the skimmer and draw from the main drain. The second picture is the output as it enters the pool. For convenience sake I have the probe inserted through a hole that I drilled. This probe measures temperature off the tip. The probe is inserted to the mid point of the stream of water in the pipe. This is in a shaded area so no impact from the sun, and in case you're going to ask YES i also tested it by holding it in the direct stream and its the same temperate.

As for the pool temp itself, I tested the pool in different areas and it is uniform, no variation which is not a surprise because the current from my jets mixes the pool really well....big pump small pool.

Today I'm only getting 3 degrees. I am sure that is because it is a cold day, only 74 degrees. As I mentioned before, I am positive that some of the heat generation comes from radiant energy from the roof. Today the roof is nearly 20 degrees cooler than normal days when the air temp is higher and there is no wind....today we have a fairly brisk cool wind as we have a cold front passing through.

I've measured the flow several times, its always in the 15 GPM range, but I will do that again to show you when I have more time, but for now at least you see that I am getting 3 degrees.

More Stats: This morning at 10am I got 2 degrees, by 11am it was 3 degrees and its maintained that up until now. It should stay around that until 4 PM when it starts to drop fast as the sun goes lower

.input.JPGoutput.JPG
 
So your detailed post inspired me to go back and read through all of your posts and see if I missed anything and I might have. Originally, in your first couple of posts, I had read that you have 1000' of 1/2" tubing. But what I missed was later on you mentioned something about some PVC pipe. So my question is during these tests, specifically the last one, what was active and what was not active. That might account for the difference.

Also, you mentioned that the panels were 8' in diameter but that would make the total area to be much larger than the 1000' of 1/2" pipe. Even if you assume that the tube is actually 0.7" O.D. the area of 500' of tube would be 29 sq-ft but an 8' circle is 50 sq-ft so either there are significant gaps between the tubes or tubing is longer than what was posted. It also looks to be a little flattened in the photo.
 
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