SmartPool/Fafco Solar panel install.. build notes/questions on check sensor?

theskyisthelimit99

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Jun 28, 2016
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Pittsburgh, pa
Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

Unless you a diverter valve designed for the system to drain, it most likely is not. When the solar is bypassed, your check valves will (pretty much) stop the water that can move 'backwards'.
Yep, thats what i assumed.. so all is good.. i just had to get past the whole initially purging process.. now i'm anxious to see the "real" results in the coming days
 

jblizzle

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Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

A 2psi pressure rise with the solar on seems reasonable.

The panels should drain when the pump is turned off (the controller will likely turn the solar valve off to). If water is left in them with no flow and in the sun, they can get crazy hot and damage the plastic. I would worry more about those horizontal panels sagging too.

You could add a small crossover between the solar supply and return to let them drain and not have to go through the solar valve.

Every morning when my pump turns on and the solar turns on, I get all the churning and air blowing into the pool.
 

CJadamec

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Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

The solar diverter valves that drain back simply have a small, like 1/8" or smaller, hole drilled in the valve ball that allows water to got back thru it when the solar panels are shut off. When the pump is running the amount of water that goes thru that hole is insignificant but it allows the water to slowly drain out of the panels when the pump is off.
 

theskyisthelimit99

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Jun 28, 2016
386
Pittsburgh, pa
Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

A 2psi pressure rise with the solar on seems reasonable.

The panels should drain when the pump is turned off (the controller will likely turn the solar valve off to). If water is left in them with no flow and in the sun, they can get crazy hot and damage the plastic. I would worry more about those horizontal panels sagging too.

You could add a small crossover between the solar supply and return to let them drain and not have to go through the solar valve.

Every morning when my pump turns on and the solar turns on, I get all the churning and air blowing into the pool.
Where would this crossover be exactly.. i think Dom has one on his, not sure if its the same idea? Just after the check valve (closer to the panels side) across from input to output?) I guess visually not following how it would drain them, or is it meant to keep flow going and not drain them but not pull the warm hot water into the pool after a peak temp is hit? edit: i guess the crossover would allow water to drain from the input (to solar) side, over to the solar return side, then out into the pool so long as the valve was on solar off position.

- - - Updated - - -

The solar diverter valves that drain back simply have a small, like 1/8" or smaller, hole drilled in the valve ball that allows water to got back thru it when the solar panels are shut off. When the pump is running the amount of water that goes thru that hole is insignificant but it allows the water to slowly drain out of the panels when the pump is off.
I think i recall the hayward valve mentioning something about drilling a hole into the valve, but cant recall.. i'm trying to visualize this as well.. how this would allow for the panels to slowly drain.. ie: the closed valve when solar is off, is shutoff to the left.. does it just allow for water to come "backwards" from the solar outbound line on the left to trickle towards the return i take it?

Not sure this vs the crossover which would be simpler to implement now, after the fact.. i could take apart the valve and maybe drill from an angle into the closed part, a 1/8" hole couldnt I? I'd have to shut everything off etc first
 

jblizzle

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Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

Correct The Crossover with just go anywhere between the check valve and the solar panels. The advantage to this is if you have the solar valve off there it would be no water heading up toward the panels whereas you will get a little bit of flow that direction if you drill the hole in your diverter.

Drilling the hole is the easiest option because you would end up pulling the diverter out of the valve body and could just put a hole in it. I use the Pentair solar valve that includes a small check valve built into the diverter.
 

theskyisthelimit99

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Jun 28, 2016
386
Pittsburgh, pa
Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

Correct The Crossover with just go anywhere between the check valve and the solar panels. The advantage to this is if you have the solar valve off there it would be no water heading up toward the panels whereas you will get a little bit of flow that direction if you drill the hole in your diverter.

Drilling the hole is the easiest option because you would end up pulling the diverter out of the valve body and could just put a hole in it. I use the Pentair solar valve that includes a small check valve built into the diverter.
So on the crossover it would just go here as in yellow in the pic, straight pvc off angled tees on each side? (unsure, but maybe a union in the middle too) edit: i guess i could do this crossover with 90 degree tee's outside just below my drain valves on the garage wall too right?)

or


With the option of taking the diverter apart and drilling that 1/8" hole (in the middle of the closed valve portion i assume?).. so this would just allow a 1/8" flow of water back up into the panels then? Thats enough to keep them from melting/causing issues up on the roof?

So it sounds if i have two choices.. pvc cuts, use crossover which will result in a drain of the panels... vs drill a small hole in the diverter which may allow enough flow to prevent an overheat (but would it cause enough "cool" water to come back down when you dont want it to, i guess not?)..

Sounds simpler to do the hole, but maybe more effective to do the crossover.

Leaning towards the hole, assuming its adequate, if i understand this correctly? EDIT: given how i may be able to do this right at the garage wall area, maybe the crossover isnt so bad and the better bet anyway, though each time it starts up, the whole air purge...
 

jblizzle

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Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

The hole in the diverter would just allow the solar panels to drain when the pump and solar valve were off. But, it could allow some water to head toward the solar panels (maybe not all the way up) when the solar valve was off.

I have a solar diverter and a cross over.

The way I did the cross over was on the vertical pipes. I put in Tees facing away from the water and offset about a foot or so. Build a U of pipe and 90s (hint, you can buy a reducer to put in the 2" Tee and only use a small 3/4" for the crossover) with a ball valve in the middle that would fit between the 2 Tees. A little tricky to make sure the U can then be "glued" into both the Tees at the same time. Then I just have the ball valve slightly cracked open so that the supply pipe can drain back through the return pipe. I put the Tee for the supply up higher than for the return so that when in solar mode, there was less likely hood of the water to make the 135 degree turn to skip the solar panels.
 

theskyisthelimit99

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Jun 28, 2016
386
Pittsburgh, pa
Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

The hole in the diverter would just allow the solar panels to drain when the pump and solar valve were off. But, it could allow some water to head toward the solar panels (maybe not all the way up) when the solar valve was off.

I have a solar diverter and a cross over.

The way I did the cross over was on the vertical pipes. I put in Tees facing away from the water and offset about a foot or so. Build a U of pipe and 90s (hint, you can buy a reducer to put in the 2" Tee and only use a small 3/4" for the crossover) with a ball valve in the middle that would fit between the 2 Tees. A little tricky to make sure the U can then be "glued" into both the Tees at the same time. Then I just have the ball valve slightly cracked open so that the supply pipe can drain back through the return pipe. I put the Tee for the supply up higher than for the return so that when in solar mode, there was less likely hood of the water to make the 135 degree turn to skip the solar panels.
So doing the cross over would be more effective and not have any "cold" water seeping back around the system when its off i take it? My idea of putting it on the garage vertical pipes below the drains would then work? Do you have a picture of what you describe or what you did.. Sounds like having them vertical is better than either A: dealing with under the deck or B: having them on the ground horizontal. I'm not picturing this U though.. are you saying a U because I would have very little room to work with between the pipes.. i forget off hand, maybe only 3".. So the a slanted diagonal of some kind? Then forgo the need to put the hole in the diverter. If i thought the diverter hole alone would be ok and not have Any negative impact then i'd just do that and be done i guess.

I think i read somewhere that if you have the vac breaker installed at the top, that the system should still drain via the siphon effect when off, or maybe that was only with the 1/8 hole in place? Maybe this is why the need to do the crossover then, so while the pump runs during the heat of the day, if the solar is off, it can still drain?

I guess either way (or only if using the hole method?) the panels wont drain unless the pump is off in addition to the hayward/actuator being in the off position? If the vac breaker + leaky hole does the job well enough Alone despite small seepage back into the system, how can i test this if i put the hole in, ie: how will i know for sure if its draining (any).. the sound of gurgling on startup like i had full blown before?
 

domct203

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Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

I have a bypass loop inside the solar loop, I use it to regulate flow/pressure as my panels do not drain (they are on a rack below water level). I set the bypass valve so there is only a 2.5-3psi increase with the solar running. This seems to keep the panels cool to the touch when running, and also returns water that is a couple of degrees warmer than the pool.

I don't worry about draining as my pool never reaches the set temperature on the controller. So if it's sunny, my system is always running. By 5:00-5:30pm the panels (& most of the pool) are in the shade.

bypass loop.jpg
 

jblizzle

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Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

Yep that's basically what mine looks like too. I just used a smaller pipe and smaller ball valve
 

theskyisthelimit99

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Jun 28, 2016
386
Pittsburgh, pa
Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

I have a bypass loop inside the solar loop, I use it to regulate flow/pressure as my panels do not drain (they are on a rack below water level). I set the bypass valve so there is only a 2.5-3psi increase with the solar running. This seems to keep the panels cool to the touch when running, and also returns water that is a couple of degrees warmer than the pool.

I don't worry about draining as my pool never reaches the set temperature on the controller. So if it's sunny, my system is always running. By 5:00-5:30pm the panels (& most of the pool) are in the shade.
Thats the thing, i dont have stats yet to know if ill hit the 82F setting on the control panel or if when i do, how hot they will get. On crossover.. i guess if i do an extreme angle or maybe make 2-3" come outward from the garage wall pipes, it will give me more room to cross over so to speak, if i later find this is needed. Its strange though, in glancing around on the net you dont see the crossover mentioned much at all, its usually the hole method only.

edit: coming to understand as well.. i think.. that since the pump will be on when solar is off.. technically with either method, the panels wont drain due to pressure being applied to the system, so its really not effective at least on the same day.. they wouldnt drain till the pump shuts off in my case at 7pm at night, by then cooled anyway. They should/could actually reach 140+ with or without water too, unsure how any of this helps with that.
 

theskyisthelimit99

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Jun 28, 2016
386
Pittsburgh, pa
Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

I spoke to the manufacturer of these panels today.. they stated that you dont need to worry about the drain feature when the solar is off.

I did notice, i had pulled the plug, while solar was still on.. turned it back on, it did the initial chug and purge thing it did before.. so it must have partially drained in the 5 mins it was off or got air into the system.

Either way, i still dont see how water sitting in the panels (stagnant) vs water moving around in them would make a difference (on vs off) on a hot day, where they will reach say 140F either way.
I guess i'm not going to worry for now. I could later just do the hole in the diverter option and skip the crossover.

I've been gaining about 2F on days where most of the day the solar was off.. i'm guessing maybe on 2-3 hours max if that (rain/clouds/mix/high 65-67 etc).. solar cover to go back on for a week starting tomorrow.. last day for testing this skim-it device for the skimmer today.
 

jblizzle

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Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

If there is water moving in the panel's they do not get hot when you touch them and they feel cool. If you let the water just sit in there it will get very very hot which is going to weaken in the plastic.

If they were on a flat roof I would have much less concern but since they're sloped and they will get hot and weaken the plastic that's when those horizontal solar panels start to sag.
 

theskyisthelimit99

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Jun 28, 2016
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Pittsburgh, pa
Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

Update on delta T readings...

today, near surface, pool temp was at 66F mid day.. output from solar was 74.. 8 degrees difference.. its been averaging 6-8F at least each day.. the other day about 7F difference, mostly cloud high 72.. today, intermittent sun and 79.

Not sure if 8F is considered heating "a lot of water a little at a time" or not.. i guess its a good thing.
 

theskyisthelimit99

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Jun 28, 2016
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Pittsburgh, pa
Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

Incredible day of heating here or at least the delta.. max temp was 81F air temp today.. lots of sunshine too

I didnt check the pool till around 1130am, by then the pool water temp was around 68.. i checked the output from solar it was reading 78.. by days end.. this at 5pm.. the water reached 72F and the output was at 82F.. a difference of 10 degrees there... so it averaged 9-10F delta T all day even in the very late day when the sun was lower.

I have the cover on now.. its still 72F.. will see what it is at 8am and then check at the days end though its supposed to be more cloudy and 75 with chance of rain.

I also tested the panels with solar on and pump running.. cool to the touch.. i didnt think it was hot enough to try a solar off/pump running test to see if they get super hot with standing water inside.
 

theskyisthelimit99

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Jun 28, 2016
386
Pittsburgh, pa
Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

Forgot to add from last night that the one thing i did notice though, was the solar was still ON at around 9pm, after it was getting pretty dark.. the outside temp was about 74-76 at that point.. maybe the roof temperature sensor just figured the outside temp still justified being turned on, unsure.. i guess the sensor really doesnt detect sun, more on the temperature

Pool was sitting at about 69.5 this morning.. lost about 2.5 degrees again despite cover.. i wonder if the fact i cant cover up a small area near the ladder ends up with this loss as a result. I lose 3-5 (5 being rare) without dealing with the cover
 

domct203

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Re: SmartPool/Fafco Solar panel install.. build notes/questions on lack of psi change

If the air temp is warmer than the pool the solar will run, trying to grab some of that heat from the air.
 
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