Advice Needed! Installing some used Fafco solar panels....

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leibin

leibin

0
LifeTime Supporter
May 18, 2010
53
Prescott Valley AZ
All,

I've been doing some research on what I will need to get my recently purchased 4x12 2" header Fafco solar panels installed. I purchased 8 of them. At least two have a hole or two. I am planning on building a raised platform to install the panels, as I have a dead space in the yard that is about 26'x14'. I plan on installing 6 of the panels.

Question 1: Can I plug these couple of damaged lines with some adhesive cement or something that will not burn/eat its way into the adjacent tubes?

The person that I bought them from was a photovoltaic installer, and removed these Fafco panels for the PV install. His installers cut the couplers that join the panels together. It looks like some kind of re-enforced rubber tubing. I do have one good coupler, and a couple of end plugs, which I will need.

Question 2: Anyone know of a suitable coupler replacement without purchasing the $15/ea couplers?

As far as the design goes, I know I will need a vacuum release at the lower/entry point into the panels for drainage, even though I don't plan on draining them, and we might see a couple of days a year where the temp drops below freezing (I could just set the pool to run from midnight to 9am or so in the winter. I'm located in the Phoenix area). Also, I see that I will need a valve where the piping goes out to the solar system (manual is fine with me), and I'm assuming a check valve on the return line from the solar back to the system, so that water doesn't go backwards. I plan on plumbing the system in just past the filter and prior to the chlorine generator.

What am I missing, and any advice here would be greatly appreciated!
 
Re: Advice Needed! Installing some used Fafco solar panels.

Update: I went ahead and purchased the Fafco couplers from Fafco - great customer support out of the FL office, btw. They were $5 each, needed 12. Also picked up two of the PVC-to-coupler adapters for $10 each. I should have all that I need for the panels now. Just built the ramp to hold the panels, pics attached!

Now, I'm trying to get the plumbing design down. I have been all over the web searching, as well as on this forum.

My setup now consists of Pentair 2hp pump going to the Pentair filter. Out from the lower end of the filter, turning, and then doubling back to the Compupool SWG. From there, it goes immediately into the main 'header' for all of the outputs.

I think that I need a check valve just after the filter output, so water can't come backwards through the filter and wash dirt into the pool. Then I'm guessing that I need to plumb from there to a 3 way valve. One output goes out to the solar, and the other one back to the SWG input. I also think that I need the output of the solar system to join there, as well - before the SWG. Another check valve where the solar output returns to the SWG.....and that's about what I've come up with. The run from the pump to the solar array is about 75' each direction, with about a 4' rise at the top of system.

Any input here would be greatly appreciated. I have limited room where the plumbing currently is. I have attached a drawing of what I'm thinking....Do I need isolation valves, ect? My though there is that the wife, or someone else my isolate the entire system, causing the filter assembly to explode from high pressure due to no-flow. Thanks in advance!
 

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Re: Advice Needed! Installing some used Fafco solar panels.

From your words about check valve placement, etc., it seems you have a good understanding. I have the isolation valves, but was told they are really only needed if there's a problem with the solar array and you want to open it up for leaks/repairs while the rest of the pool plumbing functions normally.
 
Re: Advice Needed! Installing some used Fafco solar panels.

Well, the system is now installed. Pics are attached of the plumbing near the pump, as I have a question. Before I started the project, I was seeing about 8-9psi at the cartridge filter. Now, even with the solar system isolated off, I am seeing about 16psi. The only difference is that now (with solar bypassed) I am going through a Jandy check valve, then through a Jandy 3-way valve, then through an extra 90 degree or two, and then into a tee which is connected to the CompuPool SWG. Should I have used a valve in place of the T?

With the solar completely on, I'm seeing about 28psi at the filter, which is quite high IMO. Is this expected? I'm running through about 150' of pipe, then through 5 Fafco 4x12's with a 4' rise. I guess that 12 psi over what I'm seeing with the solar bypassed (28psi solar on, 16psi solar bypassed) is ok, but how did I gain the 8psi on the system with solar bypassed? If that was not there, I'm guessing I would be seeing about 20psi in solar mode.

The filter assy says that max working psi is 50 - do I need to be worried?

Thanks!
 

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Re: Advice Needed! Installing some used Fafco solar panels.

With the solar completely off you shouldn't have seen much of a rise in pressure, maybe 1 psi. With the system set to 100% solar I would expect a large rise in pressure. You don't normally ever set it to 100% solar unless you have a lot of panels.

The diverter valve, T, and the check valve will increase flow resistance, but the change should have been very minor.

The plumbing area is crowded, so I am not 100% sure I followed everything in the photos correctly, but it looks like you did a reasonably good job at hooking everything up correctly.

There is no danger to the filter, it is fine at these pressures. The disadvantage is that your flow rate is much lower at these pressures.
 
Re: Advice Needed! Installing some used Fafco solar panels.

leibin , just to support, my original psi was 16, then I added a heat pump which added 4 -90 degree elbows and the psi went to 18. I added solar which is on a one story house, consists of about 200ft of 2inch pipe and a bunch of 90 degree elbows , 3 way valves, one way valve and the is about 24-26psi. I am however running 2 inch plumbing with a 1.5hp pump. Mas985 is a mater hydraulics person and can do all the calculations for you. Hope this helps. See my sig for solar and pool install.
 
Re: Advice Needed! Installing some used Fafco solar panels.

JasonLion - thanks for the feedback. The only thing I can see that is giving me such a rise in psi (with solar off) is the T where the filter output and solar output come together. I may try to replace the T with a 3-way valve to keep the flow from one output from fighting the other side of the T. Not sure... One other question, if I try to run the solar at less than 100%, I can see that the check valve coming from solar shows the flow rate decrease significantly, even if I just start to open the 3-way valve a little bit to allow flow from the filter. The flapper in the check valve closes down quite a bit.

Is it better to have low flow through solar join higher flow from the filter, or is it better to just try to get maximum flow from the solar system? I ended up installing 5 panels, so that's about 240sqft on the panels.
 
Re: Advice Needed! Installing some used Fafco solar panels.

Brentr - thanks for the feedback - that is pretty close to the numbers that I have on a 2hp pump. Interestingly, my pump is much quieter now with the higher psi - I can barely hear it running from the patio now! I am also 2" plumbing throughout (except the SWG, which ended up being 1.5". This caused my psi to rise from about 5psi to 9psi when I originally installed the unit. When I need to replace the SWG, I will be looking for the 2" model, as this is obviously a major bottleneck in the system now!). I checked out your sig - actually I read that link during my research! Can't see the pictures, but it sounds like you're getting great output.

My numbers from yesterday were:
7:00am - 70 degrees
4:00pm - 77 degrees.

I do have a solar cover, and this morning, I was at 74. System just turned on, hoping to see a little over 80 today. Should be able to jump in to an 88 degree pool this weekend!
 
Re: Advice Needed! Installing some used Fafco solar panels.

Can't complain about our solar. It was 94 degrees yesterday in the pool and we have been swimming at 88 degrees temp in the pool since the second week in Feburary. I have the gl-235 and I set the temperature similar to your thermostat in your home and it automatically turns on and off as needed.
 

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Re: Advice Needed! Installing some used Fafco solar panels.

Yeah, automation will need to be my next purchase ;) Looks like I can pick up that gl-235 on ebay for a couple hundred....right now, I'm in manual mode! I just set the valves, and then set the pump timer to run between about 9:30am and 4pm while my panels have direct sun. I will have to modify this schedule once the pool warms up. I'm looking forward to being able to cool the pool this summer, too. I'm guessing that once I'm trying to keep the pool steady, I will be ordering that controller!

Over 90 degrees in the water is too warm in AZ when the temps outside are 115! 86 degrees is best when it is that warm out, 88-89 when it's cooler ;). I usually have about a 3 week period where the water is too warm. Assuming the low temps at night drop below 90 during that time, I will try to cool this beast down!

More to come on automation!

Thanks Brentr
 
Re: Advice Needed! Installing some used Fafco solar panels.

Ideally you want about 6 GPM for every 40 sqft of panel, or about 36 GPM going to solar. A little more than that is alright, but much more than that will shorten the life of the panels. You have a 1.5 HP pump, which should be moving much more water than that. So my guess is that just that tiny bit open to the bypass is probably about the right setting.

Another way to do it is to measure the water temperature increase coming back from the panels. You want the lowest flow rate that gets you 2 degrees or less temperature increase (after they have been running for a while in full sun).

Neither of these is easy to do exactly as both flow rate and temperature before solar merges back with the bypass are tricky to measure. Still, that should give you an idea of the issues involved.
 
Re: Advice Needed! Installing some used Fafco solar panels.

I've got a 2hp single speed pump right now....just found an intelliflo vs3050 locally on craigslist for $150 - 4 years old. My whisperflo is older than that....would this be a good purchase to: 1) safe some dough on power, and 2) better control flow to solar, assuming I have too much flow going there now?
 
Re: Advice Needed! Installing some used Fafco solar panels.

Well, that deal was too good to be true...ended up being a used Whisperflo just like the one I have, that had a replacement motor on it which was packed in a box that said VS3050 :hammer: So....I guess I'll just visit picking up a new Intelliflo sometime down the road. My next step will have to be the Suntouch controller which will later control the Intelliflo.

Update on the temps:

Started Monday morning at 70 degrees. I forecast that I will be at 89-90 by the end of today, which is a four day run with about 7hrs of run time per day. I gain about 8 degrees per day, and then lose 2-3 degrees overnight, as our lows are in the 50's right now, highs in the mid 80's. Either way, We'll be in the pool tomorrow, if not this evening! :cheers:

I'll post some pics of the completed project once I get the PVC painted. Thanks to all for your input!
 
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