Solar Panels (Roof Mount)

[jmcst25]

I just ordered 6 solar panels (4x12) to mount permenately on the roof. The instructions look straight forward - but I was looking for any advise or 'gotchas' I should be looking for related to solar panels.

IG 18x36 Pennsylvania; 2nd floor roof is south facing - and I order the automation control - 1 HP pump cartridge filter. Have not opened pool yet -- but water is clear and chemical reading are within range. Hope to open this weekend and install panels next weekend.

Any advise of solar roof panel appreciated -- (any on installation, operation, etc ..... (please).....

Thanks again -- great forum.

[tphaggerty]

Go to powermat.com. They have lots of diagrams and advice. There are quite a few sites that have similar diagrams as well. The Heliocol website has the installation manual for their brand of panels which outlines this stuff pretty well too.

Installation tips: make sure that you angle your panels across the roof with the return coming from the TOP and the input at the opposite BOTTOM. This will allow the panels to fully fill without any air pockets and to drain completely. For a 2nd floor rooftop system like yours (and mine) you don't want all that water sitting on the roof all the time. You many need to move the vacuum breaker around some in order to prevent constant bubbling, we originally started with ours opposite the input, then moved it up, then finally installed it about 2/3 of the way up the return pipe next to the house. Depending on the valve type you are using, you may have to drill a hole in the valve ball in order to allow the input side of the system to drain back when the valve is opened. Our system called for a 1/4 inch hole.

Usage tips: Our controller just works the bypass valve, so if our filter is not running, the solar isn't either. Our system faces east (unfortunately we had no choice) so we set the filter timer EARLY (7am) and off by about 5pm when the sun is off the panels. On a bright day, the system will turn on 10 minutes after the sun hits the panels. We picked up 4 degrees yesterday (from 72 to 76) on a 20x40 inground with 8 4x14 panels, so you should do well with your south facing panels! The system will bubble a LOT each times it turns on, but all of the air should be cleared within about 3 or 4 minutes, if not you need to make sure all of your fittings are tight (first), then perhaps try moving the vacuum breaker.

Rooftop systems are (should be) OPEN, not closed loop like most onground systems. When operating, they are filled with water and do not need much pump. When first starting, your pump needs to be able to raise the water to rooftop. When off, the system should drain back, allowing air to enter the panels and all of the piping above pool level - this removes all stress from the panels.

Good Luck! (I wanted to install my system, but my better half did not want me playing around on a roof 30ft in the air).

[jmcst25]

Thanks. I'll check out those website. I purchased a Hi Deluxe from Solartrope (Harting Industry) - but I think the concepts should be the same.

I'm not sure I follow on the vacuum breaker - once I get the panels, hopefully I'll get the big picture and understand.

My better half had the same opinion about the 30 foot roof, so I found a general contractor who will go up and tack them down. Although - I have to do all of the layout / design work - and provide the guidance on what to do. So I appreciate the feedback.

Any other comments appreciated.

Thanks again!

[Poconos]

I looked at the website for the panels you mentioned and it wasn't clear what type of panels the Hi-Deluxe were. From the other listings on the page it looks like mat panels. Whatever...I can't give any specific advice but I'd be concerned about a general contractor to 'tack them down'. Unless properly installed and tied down you run the risk of roof leaks and wind damage. These things can make great wings. I'm just making the point that it isn't as simple as putting a panel on a roof. Just my quarters worth....inflation.
Al

[tphaggerty]

I agree with Poconos. Our panels are cross strapped with tie downs between every panel and locked down to the roof at the input/return headers. All of the piping is also strapped to the roof. The contractor used LOTS of silicon on every screw and all of the screws are stainless (I checked myself).

As for the vacuum breaker, you need that to allow air to reenter the system when you shut it off. A roof mount system "drains back" into the pool, without a vacuum breaker, the water in the system stays there. With a vacuum breaker the weight of the water column in your pipes will pull the breaker open, allowing air to enter the system which will allow the water to drain off of the roof back to pool level. (In reality, if your pump is running and your solar valve is OFF, the water level in the solar system will be higher than pool level because of pump level pressure going back the return line, but this is still going to allow the water to drain off of the roof).

As I said, go to powermat.com and check out the diagrams. The first page has a great animation that shows how a correctly constructed system fills up when starting, how it runs, and then how it drains back when turned off (which shows how the vacuum breaker works). There are also other animations/pictures that show how incorrectly setup systems will not work properly.

I wouldn't even think of starting to put up the system until you really understand how they should work and you have all of the proper pieces.

[jmcst25]

Thanks - I realize I was over simplifying the 'Tack them down'. I obtained quotes from several contractors - and those items you mentioned were the primary selection criteria for choosing the contractor. I choose the contractor who had the best ability to handle those types of things. (Hopefully I picked the right one - but I did ask alot of questions).

The Hi-Deluxe is a rubber mat system - and it comes with all the straps etc. We will be using galvanized anchors and all of the pipes will be anchored as well.

The term 'vacumm breaker' temporarily through me -- The HiDeluxe calls it a 3-way valve to perform that function - (http://www.solartrope.com/new/hidel.htm # 3) -- I understand it now that I reread your comment - thanks.

I've read the HiDeluxe install manual and reviewed that website -- they are pretty consistent in the concepts.

Any additional feedback experience appreciated.

[tphaggerty]

No, the vacuum breaker valve is referred to as the "vacuum relief valve #13" in your diagram. The 3 way valve is what diverts the normal pump flow to and from the panels. The vacuum breaker/relief valve really isn't a valve, it is more like a one way shut shut off.

When the system is running, the breaker is shut, no air in or out. When the system is off, the water wieght causes the breaker to open inward and admit air (it works because the vacuum pressure caused by the weight of the water in the pipes and panels trying to go home to your pool pulls it open).

But the diagram you are working from looks really good! Just remember, make sure that the system is higher at #13, my installer used a 1 foot drop over the 24 linear feet or so of our panel run.

[jmcst25]

Thanks for the clarification.

Did you say you ended up moving yours from the # 13 location to somewhere near # 3 (in this image)?

Also -- I am going to have to install on 2 different roof sections (main roof and over addition). The one roof is 1 foot higher than the other but same slope / direction. So I am going to install 3 panels on the one roof and then the 3 panels on the other roof. They are side to side.

I'm planning on feeding the 3 panels on lower section roof section then have that feed the 3 panels on the upper roof - then return to pool.

Any thoughts on this?

[tphaggerty]

We wound up with the vacuum breaker at about where the head of the big red downward pointing arrow is. But, I would start with it where they show on the diagram, it is probably threaded there. We had to cut in a threaded "T" to make ours work. We had to move it because it was continually sucking air when the system was running, but we have a 130' run from the pump to the roof (and then back), plus the piping actually dips down (to follow the yard contour) then back up, so I think we are a special case.

As far as the split, as long as the returns ALL go through the highest point, you should be OK. Actually (I hate to harp, but it is really a good site for this stuff), the www.powermat.com site has a picture of this as well. I would just run it as a single system, with your input on the lowest roof, and the return coming off the higher roof.

[jmcst25]

Thanks - I missed the link on my first pass on that site to where they show the 2 sets on Panels - http://www.powermat.com/PG5ht.html - that explains a lot -- thanks. The installation should go alot smoother - ( I tool the before pictures.)

Also -- I opened the pool today -- crystal clear and all the numbers are in check! - but only 54 degrees. This forum closing instructions made it work without any problems.

Now hopefully soon I'll have the solar panels to raise the temp.

[jmcst25]

You many need to move the vacuum breaker around some in order to prevent constant bubbling, we originally started with ours opposite the input, then moved it up, then finally installed it about 2/3 of the way up the return pipe next to the house.


Thanks again for the Info -- we finished the installation Saturday.

I am having problem with air in the system. We have the panels on two different roofs - with about 150 of piping. We installed the vacuum relief as indicated -- but when we send all of the water through the panels -- we get air -- however, when I send some water to the roof and some through the bypass -- no air. I'm guessing their is too much pressuring going down with full water ( causing a syphon effect ) pulling the vacuum and letting air in - but with partial water pressure it balances out and no air. Now, if this were the case, wouldn't the vacuum be stronger 2/3 way up on the return pipe and let air in? I was thinking it needed to be lower on the supply so more water pressure kept it closed? (This vacuum relief really confuses me).

Any suggestions appreciated (please).

Any suggestion appreciated - I

[tphaggerty]

We had problems with air getting in the system as well. We LOWERED our vacuum breaker and that worked (it is now on the return pipe about 3 feet below the panels which are on the 2nd story roof). We first had it opposite the input, then opposite the top return, neither worked. The installation manual for the Aquatherm panels we have then suggested the location we have now and it works great.

We cut a T into the return line about 16 feet up and attached the breaker there.

[jmcst25]

Thanks --

Question -- I believe that the water is going down the return to fast which is causing the vacuum. Wouldn't the vacuum be greater on the return line? I was thinking I needed to move it down on the supply line where their would be more pressure to keep it closed.

I was also considering putting a ball valve on the return line and restricting return flow to minimize vacuum -- will this work -- or is that a bad idea.

I'm just trying to figure this stuff out. (especially - since I'm paying someone to get up on the roof - I want to get it done as short as possible).

BTW -- tphaggerty -- thanks for all your experiences and recommendations.

[pilot]

I am thinking about getting a system, what kind of increase are you seeing, I have a 18 x 36 in ground.


Thanks

[jmcst25]

It went from 55 to 76 in 2 days - with air temp > 80 in Western PA. I just installed Saturday. My pool is about the same size as yours.

The install was trickier than I originally thought -- (meaning planning the layout and getting all the right parts).

tphaggerty recommended a site call www.powermat.com to gain an understanding of what is involved -- it is really worth the time to read up on them. I bought from solartrope - before gettting information on that site. Powermat does a much better job explaining things. Next time around -- I'd consider paying a little more for a dealer to install -- but there are no dealers in my area that install solar.

I still have to go up and replace some parts that I did not originally order -- ( I did a make shift fix to split the panels to get them working.) I spoke with the dealer today -- he told me the same fix as tphaggerty did to lower the vacuum on the return line. He said the too much air is a common thing.

Best of luck.