Solar Panel Features and Decisions

[ddegentesh]

We have an 18x36 Vinyl IG being built in the spring. Thanks to this forum I've gone from complete neophyte (I never even knew someone who had a pool) to being almost literate. You've all helped me make some more intelligent decisions regarding my pump, filter, and chlorination equipment. Because of this site I'm also completely intrigued by solar. I have a big west-facing roof, high on a hilltop with unimpeded access to direct sunlight. So I'm convinced that with enough panels we won't need supplemental heat here in the Pittsburgh area.

A few questions:

First: I read up on the UCF site and I'm aware of how they characterize panel performance -- that helps narrow my decisions. My questions now regard a few of the features of different types. It seems the panels are one of three types: a) rigid risers that are interconnected (Fafco Revolution, Aquatherm) b) rigid risers that are not interconnected (Fafco ST, Heliocol) and c) flexible risers (SunTrek, Hot Sun/Powerstrip). Which of these types:

1) are least likely to damage the roof -- I have perhaps unfounded concerns about the panels rubbing my asphalt shingles and causing damage?
2) are most likely to survive strong winds -- It seems that they all must, but does anyone have direct experience with either success or failure in strong winds?
3) are most likely to survive freeze-thaw cycles -- it's 27F and snowing outside my window as I type this.
4) are least likely to leak -- Is this really damning post (http://www.poolspaforum.com/forum/index ... opic=36970) typical? How often are you all up on your roofs plugging holes?

Next: how do you acquire these Dang things? Solar power isn't exactly huge in Pittsburgh, and the one solar dealer that called me back has installed exactly 1 of these systems. I'm not afraid of DIY, but it doesn't seem like the big brands that you all talk about -- Fafco and Heliocol -- have online dealers. I've checked ebay and I don't see anything for sale at the moment..I'd prefer new.

Lastly , if any of you in colder climates can share typical temps you've achieved throughout the season I'd appreciate it. More data points == more confidence. And in the odd chance there's a Pittsburgh area person on here with direct experience, I would gladly buy you a beer or three in exchange for a conversation about your experiences.

Thanks in advance.

 

[CB]

Both Amazon and Ebay sell Fafco panels and mounting kits as well as every online pool supplier.I have been looking into solar as well so I. can't offer you any actual experience.
Search for "solar panels pool"

 

[jblizzle]

Panels with tubes that are not connected allow the wind to pass through ... so likely better for higher winds. I think you can get by with fewer connections to the roof due to this. Although all panels have mounts that are designed to handle the wind load.

The connected tubes "might" heat slightly better due to the lack of air passing through.

I like the way the Heliocol panels attach to each other. They do not use hose and clamps that I have heard need replaced every so often. Problem is they do not sell to the public. I got mine off of craigslist and did the install myself ... a little hard to get parts.

If the setup is done correctly and you ensure the panels are drained in the winter, then freezing should not be a problem.

I only have experience with Heliocol. Installed by them on my first house and by me on my current house.

Posted from my Droid with Tapatalk ... sorry if my response is short

 

[Nova13]

In central Florida I see a ton of Fafco panels on roofs, I'm told they survived the storms here very well.

You can diy, lookup solar direct online for info & pricing, Ebay I would be worried about warranty.

Amazon gets 15% commission from the merchants selling products so you can usually find them for less (not just solar most things)

I'm installing my own it really is simple I think.

As far as abrasion on shingles get a roll of 12" aluminum flashing at like HD cut it where it may rub to fit, use small nails and silicone in place.

 

[4mom23girls]

Did you make your decision? We are at the same juncture of choosing panels. We would NOT be installing on our own and have quotes for a couple systems (Heliocol and Aquatherm). Of course, Heliocol rep claims his is the best and the Aquatherm dealer claims his is the best. So who do you trust? For me, there are concerns: drilling into our roof, which parts will break down over time, and of course, who delivers the best warm water to the pool. Our roof is a one-story, facing south and no concerns over freezing water (San Diego). Perhaps we need to get a quote from Fafco. Opinions.

 

[ddegentesh]

I'm leaning strongly toward Heliocol. Here's why:

* Heliocol panels are 'vented' meaning the tubes are separate, individual entities. That way, if wind blows across the panel, the pressure is equalized between the front and back surfaces and no lift can be gained. This means the panels are secured without straps, which greatly reduces the number of roof penetrations (I'm guessing 4 penetrations per panel a vented system, vs 10-12 penetrations with a non-vented system with straps).
* The individual tube system accommodates things like vent stacks and fan exhausts fairly easily by bending around them. In a non-vented system I'd have to either move the penetrations or space the panels apart farther, losing surface area for heat.
* Heliocol has a clip system for mounting that does not require mounting the panels where they are joined (usually 48" spacing). So mounting to my roof, which is partially framed with joists 16" OC and partially with trusses 24" OC, is easier. Also, the clips secure the panels by the manifolds, not by the joints, surely a stronger mounting point. And you could put clips every 24" if you wanted extra security.
* The clips also elevate the manifolds off the roof a bit, which assuaged my fear about shingle abrasion
* The panels are joined together without pipe clamps, which I like.

I felt like these features address most of the issues I raised. I'm sure others have strong opinions in other directions, however.

I did decide that I need an installer, because my roof is 7/12 and it's a bit too steep for me to walk. I have not yet successfully found an installer in the Pittsburgh area however

 

[linen]

* Heliocol panels are 'vented' meaning the tubes are separate, individual entities. That way, if wind blows across the panel, the pressure is equalized between the front and back surfaces and no lift can be gained. This means the panels are secured without straps, which greatly reduces the number of roof penetrations (I'm guessing 4 penetrations per panel a vented system, vs 10-12 penetrations with a non-vented system with straps).

From what I have heard, heliocol panels are pretty well regarded. One thing to be aware of though (as I understand it), by having separate tubes the design allows more cooling of the panels due to the ability to have more convective heat transfer, possibly reducing the total output especially on windy days.

Edit: Oops, I just noticed jbliz already mentioned this potential drawback

 

[jblizzle]

I agree with all the pluses you mentioned, but will comment on this one:

* The clips also elevate the manifolds off the roof a bit, which assuaged my fear about shingle abrasion

The gator clips only elevate the header pipes by about 1/2" or so. There are also a bunch of clip bars across the small tubes to hold them and keep them in-line. These will actually rest on the roof surface and depending on how much the panels change size due to thermal changes, could still rub the roof.

Note that for each 4' panel, they recommend 2 upper gator clips and 1 lower gator clip (especially on steep roofs ... I did no use so many as my roof is fairly flat). The upper gator clips are fixed tight to the upper header. The lower gator clips are slotted to allow expansion and contraction over a few inches. The lower headers are elevated so they will not rub, but like I said the cross bars holding the tubes may move some.

I have not noticed movement yet, but it has been less than a year. I did find that I am getting dirt/leaves trapped above these cross pieces and was just today considering adding some vertical bars to elevate cross bars so that the rain and dirt did not get trapped. However, I think this would require 4-8 vertical bars per 4' panel (since I think the cross bars are only 1' wide and there are 4 in every row) and that seems like excessive work.

 

[ddegentesh]

The FSEC ratings for most panels are around 1000 BTU/ft^2 (960 for Heliocol, 1060 for Fafco Revolution -- keep in mind the center states that ratings within 25 BTU/ft^2 are effectively equivalent). Certainly not having the webbing decreases irradiated area.

It's hard to say how venting would affect convective heat transfer. Wind will certainly pass on both sides of a solid panel, so it seems like both solid and vented panels are well exposed to convective forces.

 

[4mom23girls]

So essentially you're saying the Fafco having the webbed tubes is more efficient. I'd be curious to know if you've heard of or had any problems with movement of the O ring on the Heliocol. The Aquatherma rep said every system will have movement and the O ring will eventually separate (vs. using the clamps, which penetrate through the roof). Gosh, I don't know what is worse.

 

[jblizzle]

Not sure what o ring you are taking about. There is a large rubber sleeve that is sealed in a groove. There are then clamps over the connections that prevent them from coming apart. I do not see how they could start leaking. I did use all new gaskets on my install, but the old ones still looked fine.

Posted from my Droid with Tapatalk ... sorry if my response is short

 

[chiefwej]

I have a Heliocol system with somewhere over 500 square ft of panels on my roof. It's been in place for about 7 years and I have had only one small leak from a failed O-ring. A phone call and they came out and fixed it. My neighbor has the same system and has had several service calls for the O-rings. The good news is that it has been all handled under warranty at no cost and no water damage to anything.

All in all, I've been happy with the system, except for the controller. That I replaced with a Pentair Solar Touch digital unit.

 

[linen]

The FSEC ratings for most panels are around 1000 BTU/ft^2 (960 for Heliocol, 1060 for Fafco Revolution -- keep in mind the center states that ratings within 25 BTU/ft^2 are effectively equivalent). Certainly not having the webbing decreases irradiated area.

It's hard to say how venting would affect convective heat transfer. Wind will certainly pass on both sides of a solid panel, so it seems like both solid and vented panels are well exposed to convective forces.

good points ddegentesh!

 

[4mom23girls]

This brings up another good point. The Aquatherm / Ecosun (or Fafco for that matter) panels would lay right over the attic vents. When we asked the Aquatherm rep about this, he said, "Oh, pretend I didn't see those." In other words, it wouldn't pass code. Not sure Heliocol would pass code either, but they wouldn't be blocking the vents.

 

[linen]

The Aquatherm / Ecosun (or Fafco for that matter) panels would lay right over the attic vents.

I would think a closed panel design would not be good over vents. I would think the vents would probably still vent fine, but I would be worried about wearing out the panels quickly...and wind could get under them easier.

If I were you, I would find another layout that avoids this, or maybe consider the individual tube panels such as the aforementioned heliocol.

 

[4mom23girls]

Thank you all for all your knowledge! We have made the decision to go with Heliocol. I think there a pros and cons to all 3 recommended systems. The key is we'll get the warm water that we need. Now if we could just get the rep down in price!