solar panel install question

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pensfan76

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Jun 27, 2012
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Just ordered a solar panel. Its going to be on a garage roof about 30ft from the pump. What is the best pipe or hose to use. It will be mounted on a fence for most of the run. I'm trying to stay away from using too many 90° turns
 
You can paint the pipes if you like, although I doubt it would make much difference.

Better to use the 2" pipe where you can to lower the head loss and increase the flow rates.
 
It is generally a good idea to paint PVC pipes to help prevent UV degradation over time. If the PVC pipe is in the sunlight it will tend to collect heat even if unpainted. PVC pipe has an IR emissivity of .92 which means it is a fairly good radiator of heat, so in a perfect world if being routed through a shaded area, it would be best to reduce the emissivity of the PVC pipe so that it radiates less heat, the easiest method I can think of to achieve this would likely be the shiny silver foil duct sealing tape commonly used in HVAC applications (not the gray "duct" tape), this only addresses heat lost by radiation, not convection or conduction, which would require a true insulated wrap, these typically have an emissivity of below .30, some are MUCH lower.

Ike

p.s. if you do paint your pvc pipes with common spray paint you will slightly increase the emissivity (regardless of color of paint) as most spray paints have an emissivity over .96, some (even white ones) have an emissivity over .99
 
Very helpful info. Thank you. What about using 90° elbows? Use them or just use flexible pool hose when I come off the fence? The pipe will be at the top of the fence so I either 90 it down to the ground or let pool hose hang
 
Using 90s is fine.
You should have a check valve after the filter before the split to the solar and a check valve on the solar return pipe before it Tees back into the main plumbing. You should also have a vacuum release valve (VRV) in the system that will allow the panels to drain when the pump turns off.
 
90 degree elbows are a source of added head, however if you use 2 inch PVC it should not be enough to matter. (I don't have the numbers in front of me, but at typical panel flow levels the added head for 2 inch 90's is a fraction of the head with 1.5 inch). As to the other questions, a shut off valve is good to have, you also want to install a vacuum breaker valve so the panels will self drain when the pump is not running. Water left in non circulating panels is a prime cause of premature panel failure.
 
Interesting,
I will be running my solar to the roof of my patio along a fence as well, was going to start at the bottom of the fence near the pump location and angle the pipe to the top of the fence (about a 12' run of pipe on the fence), at the top of the fence I would run the pipe to the the roof. I was planning on using 2" PVC but wanted to 45 degree elbows where I could. I see in your Signature that you have a Hayward pump, which model is the pump. I need to ensure that I have enough power from the pump to effectively run the water to the solar panels?
 

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Are the check valves and vacuum release valves available at lowes? So just a valve to open the side to the heater and 1 to close it from going to the pool is all I need? Any advice how to secure it to the roof? I was going to lay thin pieces of wood across it every few ft and screw to the roof and clamp the ends down.
 
titleistseemore said:
Interesting,
I will be running my solar to the roof of my patio along a fence as well, was going to start at the bottom of the fence near the pump location and angle the pipe to the top of the fence (about a 12' run of pipe on the fence), at the top of the fence I would run the pipe to the the roof. I was planning on using 2" PVC but wanted to 45 degree elbows where I could. I see in your Signature that you have a Hayward pump, which model is the pump. I need to ensure that I have enough power from the pump to effectively run the water to the solar panels?
Click to expand...
Its a power flo lx model sp1510z1xbc
 
Lowes does sell a brass vacuum relief valve made by Watts that will work fine (model N36 or LFN36, mine is a 3/4 inch, but I think they make other sizes), and may sell PVC check valves, just watch out as they tend to be the spring type check valves, not the flap type. Spring valves are not neccessarilly bad, but do add backpressure, between 1/2 - 2 psi which can greatly limit flow.

There are lots of types of roofs, and types of solar panels, I would suggest looking at some installation manuals for major brands of panels like these, and others
http://www.elmdistribution.com/wp-content/uploads/2013/04/ELM-Manual.pdf
http://www.techno-solis.com/pdfs/TS-Pool Solar-Manual.pdf

Ike

p.s. For optimal performance you may want to get a solar controller like the GL-235 or pentair suntouch, and an automatic valve, this will only turn on the solar heater when it would add heat to the pool, and turn if off at times it would loose heat. Around here we get a lot of afternoon thunderstorms which could sap a lot of heat from the panels if they were on when cold rain was falling.
 
Thanks for the info on the Pump. I went to the Hayward site and found some Hayward filters that come that come with the pump matched. I selected a 1HP Power-Flo LX model with a cartridge filter C550. The 550 and the 400 filter both come with the same pump so I figured to go with the larger filter. The price is the same at Amazon. This should take my worries out of the way. I have been extremely concerned that I would not have a big enough pump to feed the solar panels on the roof effectively. I am going to order the pump this week, Isaac do you think the Hayward Pump would be able to handle that Height (10' up and about 30' horizontal run of Pipe upto 4 solar collectors)?
 
would the low speed of the pump be able to feed the solar panels effectively? (Height will be 10' up and about 30' horizontal run of Pipe upto 4 solar collectors that are 4'x12')
 
Maybe, I would not recommend it. The low speed would save you money on electricity when you do not need the solar.

Realize that the most effective solar heating is at higher flow rates. Although with only 4 panels, you only need about 20 GPM through the panels.
 
Probably a good idea then, I figured that the pump would be on 6 hours per day to operate the solar and then run a little in the morning with no solar... I will try to do the math on the cost of the pumps for my electric bill and see what the difference will be.
 
I suspect the 2 speed pump would work on low once you primed the panels with the pump on high, if you were to located the vacuum breaker valve carefully so that it allowed some siphon action, but still allowed the panels to drain with the pump off. Your flow on low would likley be below the optimal level for the panels. For most 4x12 panels optimal flow is going to be between 4.5 -5 gpm per panel, however performance does not seem to generally drop off too much until the flow drops below about 3 gpm per panel.
 

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