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Thread: Planning solar install

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    Planning solar install

    As i mentioned in another thread, I am planning my solar install right now.

    The roof I have to build on is about 12'x12', so I was going to go with 4 of the 10' panels. I figure thats the equivalent sq footage of two 2x20 panels. My pool is only an 18' round with about 8000 gallons in it.

    In looking around, it looks like the 10' panels are intended to be mounted vertically, which doesnt seem logical to me.

    Take a look at this installation guide I got off one of the websites:



    Wouldnt the panel to far right get a ton of flow, and the panel to the far left get almost none? I assume the bottom left corner would also be the lowest point in the system, with the upper right corner being the highest.

    Thoughts?
    18' Round ABG (8000 gallon)
    Hayward X-Stream Cartridge Filter
    1.5hp Hayward PowerFlo Matrix Pump
    80 sq. ft. solar panels
    Goldline automated solar controller

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    Mod Squad JohnT's Avatar
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    Re: Planning solar install

    I don't like that install because you can't make it both self-draining for water and self-purging for air. IMO, you are better off having the outlet on the upper left and tilting the panels so the lower right is the low point.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

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    Re: Planning solar install

    Ah, now that makes sense!

    I think I am going to go with the vertical install they recommend then, and do what you suggested. That makes perfect sense to me from a "how the water will flow" perspective.


    I think I've got it all planned out now, on to the ordering!
    18' Round ABG (8000 gallon)
    Hayward X-Stream Cartridge Filter
    1.5hp Hayward PowerFlo Matrix Pump
    80 sq. ft. solar panels
    Goldline automated solar controller

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    JasonLion's Avatar
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    Re: Planning solar install

    What JohnT said. You want to "twist"/tilt the entire array so that the vacuum relief valve is at the highest point. Then you want to run the return pipe from there (near the vacuum relief) back to the pool. The way the have it now the first panel will get too much flow and the last panel will get to little. By moving the return pipe you make all the paths the water can take be the same length and balance out the flow.

    Having the individual panels run up and down the roof is the best setup. The water rises as it warms up through the panel, so natural convection aids the water flow (just slightly).
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

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    Re: Planning solar install

    Yes, they are both correct. You want the return line to the pool on the OPPOSITE side as the inlet from the filter. If not, the panel to the right will get most of the flow, making the additional panels worthless. I am new to pool ownership, but I have invested far too many hours researching these. In the end, I'm not putting up 2 or 3 grand after what I've spend to fix the pool I have. I'm attempting to build my own (similar to Gull Industries coil design) with PE tubing. My best friend is a Mechanical Engineer so we have calculated the flow rate to equal that of my 1.5" PVC lines, and have already plumbed in the diverter valves. Once the coils are finished, I will lug them up to the roof and PVC them all together. I will try to set up a website with pictures and instructions so others can follow my design. I have only spent $350 with all the parts from LOWES. It is guaranteed to produce heat, but as much as the one you're installing.....Well, we'll see.
    20k inground vinyl oval, Hayward super pump 1.5 HP, Pacvac 36 DE filter, Hayward inline chlorinator, Brand new liner 2009. 1st pool ever owned.

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    Re: Planning solar install

    Which direction does your roof face? And where are you located? Have you done any calculation on how much that will save you on conventional heating?
    Concrete (gunite) inground pool and spa (80,000 litres/21,000 gallons)
    Hayward H350 natural gas heater (electronic)
    Goldline Aquarite chlorine generator
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    Re: Planning solar install

    My roof faces due south to a slight southeast. The roof is in full sun from dawn to dusk. I have done calculations to make sure I don't constrict water flow, and the valves can divert full flow to the roof, or partial if I need too. I don't know how much actual heat it will produce, but any is free compared to conventional heating. So being "realistic" I could probably get better results from a manufactured design, but I'm not putting that kind of money out right now. I have put out $350 so far, but a lot of that is the check valves and the ball valves. It is a simple coil design using 100' of PE tubing. I am using 3/4 inch tubing, as I have calculated that I can divert 100% of the flow through it to equal the pressure of my 1.5" return lines to the pool if I make at least 4 coils. I am using 2" PVC as the headers to reduce back pressure on the pump. Each coil is about 4 feet in diameter, with electrical conduit bolted together to keep the coil tight (conduit made into in "x" and bolted on the four ends and center with 2.5" carriage bolt.) Each coil will be connected to the header with a pvc tee and a reducer with a 3/4 inch threaded end for the pe connector to screw into it. I'm starting with 4 coils. After this, if I need to add coils, each one will only require the tubing ($21 for 100' unless I reduce to 1/2" which is only $12), 2 PVC tees per coil, 2 reducers, and 2 pex threaded connectors (about $8). So after I get the initial four, if I need more heat, I can built additional collectors for $20 to $30 each. The only reason I used 3/4 instead of 1/2 inch is because I would need to build at least 9 to equal the same flow for 1.5". 1.5" is probably better suited, but I don't have time to build to many of these until July. I will definitely post updates to let you know how well they work, but you can do a google search to find others who have built similar designs. One in particular http://www.thecasualtraveler.com/solar.htm is a good system with a few design flaws (from an engineering pov) the collectors are connected in series 5 at a time. The will not provide enough flow to divert all the water if desired, and will put too much pressure on the pump. He has enough coils if they were all connected in parallel (even if 2 were connected at a time in series).

    The drawbacks are mostly aesthetics and time to build each one. If you can operate a cordless drill, get up on a roof, glue PVC together, and put teflon tape on a thread, you can build your own too. With the weight involved when full of water, the only roof mounts needed are those to secure the headers. A vacuum breaker at the header would help if flow was turned off the the collectors, but because of the coil design, you will probably get only half the water to drain. PE tubing expands and contracts quite a bit, so a complete drain would not be necessary. I am including a connection by filter to attach my air compressor to blow out the water at the end of the season, but it would be easy enough for me to just unthread the PE cnnections and store the collectors during the winter.
    20k inground vinyl oval, Hayward super pump 1.5 HP, Pacvac 36 DE filter, Hayward inline chlorinator, Brand new liner 2009. 1st pool ever owned.

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    Re: Planning solar install

    I also have plans that a friend made. He has actual calculations and real world tests. Unfortunately, he sells these plans and has them copywrite protected, so I cannot post them here without his permission. He does use 250' of 1/2" tubing, with a different system to hold down the coil, and his plans call for one collector per every 150 sq feet of surface area on your pool.

    I'm gonna see what 4 3/4" coils do for me, and add more if necessary. I figure $120 to double my collector size if need be.
    20k inground vinyl oval, Hayward super pump 1.5 HP, Pacvac 36 DE filter, Hayward inline chlorinator, Brand new liner 2009. 1st pool ever owned.

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    Re: Planning solar install

    What brand of panels are you looking at? My FAFCO panels are designed for the supply and return to be on the same side, up to 7 panels. They are the only ones, that I am aware of, with this feature.

    Also, you may need to lower the vacuum break if your pump can not push the water up the panels. Some above ground pumps can not lift the water as high as the inground pumps.
    Joe

    21k IG vinyl, 300 lb. sand filter, 1hp pump, Polaris 280 cleaner, 3/4hp booster pump, 240sq ft Fafco solar, Liquidator

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    Re: Planning solar install

    I got the graphic from aquasuperstore.

    I am planning on using the 2'x10' panels from Fafco.

    If you look at the graphic, the panels are vertical, so even though the graphic shows the input/output on the same side (incorrectly I might add), the panels actually dont have the disc in them.
    18' Round ABG (8000 gallon)
    Hayward X-Stream Cartridge Filter
    1.5hp Hayward PowerFlo Matrix Pump
    80 sq. ft. solar panels
    Goldline automated solar controller

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    JasonLion's Avatar
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    Re: Planning solar install

    Panels are sold both ways. For roof mounted panels it is much better to use panels with the input and output on opposite ends of the panel. For panels to be placed on the ground, it is usually better to use panels with the input and output on the same end of the panel.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  12. Back To Top    #12

    Re: Planning solar install

    That is absolutely true. You want roof panels to have input and output on opposite sides. You also want to use vertical flow panels. The horizonal ones are not rated as well. Fafco is a good company, but not all of their products are equal. The "sungrabber" brand is their bottom line brand. It is not rated by the Florida Solar Energy Center. Check out their ratings here

    http://www.fsec.ucf.edu/en/industry/tes ... /index.htm

    They do make other brands but they are more expensive. The sungrabber I have been told has "prorated" 10 year warranty. That means you lose a percentage every year they get older. I've been told that they tend to develop leaks after 5 years. The leaks are easy to fix, by cutting the little tube and putting a screw in it, but it wasn't worth it for me. I was going to buy 320 sq ft of them for $850 until I did all my research. When I asked for the sunsaver brand, I was quoted at $2500 to $3000. That's when I decided to build by own. I should get it done this weekend and will post an update. If I get them up this weekend, I can see how well they work as we are supposed to get lots of sun next week.

    Here is one of the troubling reviews I came across that made me change my mind.

    http://www.ecosystemssolar.com/sungrabber.htm
    20k inground vinyl oval, Hayward super pump 1.5 HP, Pacvac 36 DE filter, Hayward inline chlorinator, Brand new liner 2009. 1st pool ever owned.

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    JasonLion's Avatar
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    Re: Planning solar install

    I wouldn't put too much weight on that review. Half of what they are doing there is trying to justify why their systems cost so much. Several of their points are valid, but they are normally fairly minor issues in the scheme of things.

    If you have an application that calls for them, the SunSaver/Solar Bear panels are a little more difficult to find, but they aren't all that much more expensive than the SunGrabber panels.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

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