Solar Panel Questions

haz

0
LifeTime Supporter
Feb 27, 2010
86
South Florida
Pool Size
18300
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Jandy Truclear / Ei
Split by moderator - Please start your own topic and do not hijack. Thanks, jblizzle

It sounds like people on this site are very satisfied with both Heliocol and Aquatherm. I am looking to add solar heating to my pool. It has 450 ft2 surface area, and there is a screen enclosure with 80% sun blockage on one side and most of the top, so it will have less sun exposure than its South Florida southwest exposure would otherwise offer. The roof it would be on is slanted facing southeast without any pipe stacks or any other obstacle.

I spoke with installers of each product. The BTU/ft are similar - Aquatherm Ecosun is maybe 5% more efficient. The Aquatherm rep claimed (he installs Ecosun), as others here have mentioned is possible, that these official ratings are in a lab, and that in the real world, the added air space around the Heliocol tubes would create more convective heat loss. He also said the plastic connections w/ O-ring on Heliocol were more likely to have problems than the metal pipe clamps.

He refuted the claim that the more holes would cause more leaks as the holes seem to be more into the roof tiles and the drill bits they use aren't even long enough to penetrate the layer of the roof that would cause a leak. I asked if this would be more dangerous in a hurricane if it's just mounted to the tiles, not the roof, and he said they put a glue around the tile drilled into and the surrounding ones, and in a category 4+ hurricane, better to remove the panels anyway.

He showed me a segment of Heliocol, which has 1.5" piping vs. 2" for Aquatherm Ecosun, saying the higher flow would heat the pool better. It seemed to make sense logically, but I don't know what that means in practice. Any ideas? I think most of my pool ducts are 2".

The Heliocol installer recommended 450 ft2 of panels for my 450 ft2 surface area pool. The Aquatherm Ecosun rep suggested 432 ft2 for $600 more than 450 ft2 of Heliocol, and he mentioned possibly adding more panels (480 ft2 or 560 ft2) to extend the pool season and since I will have a screen (which the usual ones block ~15% of UV and heat) with 80% UV/heat blockage on the southeast side (pool faces southwest) and most of the top.

From my sense here, enough people seem to prefer the Heliocol even if the price were the same, and the possible/theoretical decreased heating in windy conditions and ~5% decreased BTU/ft2 (any any potential effects of having 1.5" piping vs. 2" on Ecosun). Please let me know if you think otherwise.

Also, I have Aqualink controller on my pool, which via iAqualink I can control remotely. Both installers said they COULD hook it up to the Aqualink controller but think having its own control would be better. At least one will drop the price if I don't use their controller. He sort of said that his reason for not hooking up to Aqualink was that an Aqualink rep had mentioned that although Aqualink has some option of "solar priority" to heat up pool and only use the gas heater secondarily, it didn't work that well in practice. I wouldn't want it turning on the gas heater automatically if the water temperature with the solar heater wasn't hot enough yet it wasn't a time period that I wanted to use the pool. However he also hinted that he just wasn't as familiar with Aqualink vs. his own controller. Any thoughts would be much appreciated!
 
2" headers are recommended for larger installs, like yours.

In general it is better to use your existing automation system if it supports solar, rather than having a separate controller. Running two separate controllers (solar and automation system) that don't know about each other can lead to some strange quirks (nothing too terrible but still).
 
Who was giving you the Heliocol info? Their headers are 2" ... and I personally like the way those panels are attached to each other, I can not see why the 0-ring (which is really more like a think band) would have a larger chance of failure. I never had a leak on my previous house and have not on this one yet either. I have read that the panels that use radiator hoses and hose clamps have to have the hose replaced and the clamps tightened every few years.

A lot of heat is lost due to evaporation from the surface, so while the enclosure may reduce the amount of heating from the sun, it should also greatly reduce the heat lost due to evaporation (less wind).

I also can not think why you could not use the current controller you have ... likely then it could control pump speed if needed for solar. If for some reason, it did not control the solar very well, you could always add a different controller later ... but again, not sure how it would not work, it is not that hard.
 
Thanks for the responses. jblizzle, sorry for hijacking - my forum etiquette is just developing.

The Aquatherm installer carried a sample of Heliocol to compare, and eyeballing it, it looked to be 1.5", and the Ecosun he showed was definitely bigger, looked 2". Maybe this was an old version - I'm sure he doesn't get sent Heliocol's latest stuff.

The Heliocol guy mentioned that about Aquatherm, etc. possibly needing tightening of clamps occas, and I read some mention of that here on troublefreepool.com.

Logically it makes no sense for them to want to install their own panels. Both installers "recommended" their own panels. I got the idea from one that e.g. if you call them and say the system isn't working, it's easier for them to troubleshoot their own controller than to deal with the Aqualink, which seemed a bit intimidating to them. I will take youre advice - I'm going to tell them to use the Aqualink.

Good point, there should be less evaporation with a screen. But we also have a 15' waterfall in the front - kind of a front-facing vanishing edge, which increases evaporation and heat loss, but that can be turned off.

What do you guys think about the amount of ft2 I need of panels (450 ft2 of pool surface area - a little more with the spa and collecting area for the fountain), given that I'll have more UV and heat blockage with 80% blocking screen above most of and one the SE side of the pool?
 
The more panels the more heat. They are likely better at estimating the required sqft as they have eyes on as far as exposure in your application. The fact that they came up with the same initial amount is likely in the right ballpark.

I am sure either setup could have additional panels added if desired in the future.

BTW, Please add your pool details and location as described HERE so we can better offer advice in the future.
 
The Heliocol guy first suggested 400 ft2 of panel. From what I just read of the plans, my pool's 490 ft2. When I mentioned the screen and asked about extra square footage, he mentioned we could add another panel to 450 ft2.

The Aquatherm guy first suggested 432 ft2. He said we could go up to 480 ft2 or 560 ft2.
 
Just my thoughts on the matter, I just went through the selection process myself and ended up getting 11 4x12 TechnoSolis panels (going up next week with luck as a semi-DIY panel replacement project) for 528 sq ft.

1, Panel connection systems all seem to work reasonably well and seem to come in two general types, the radiator style hose and the proprietary fitting method, I live in an isolated market area, so opted the radiator hose method, as it is likely easier to get replacement parts (hose, hose clamps, etc.) in the future if brand X installer goes out of business, ect.

2, From the research I have done it seems there is some advantage to using 2 inch headers instead of 1.5 inch when installing over about 400-450 sq ft of panels. I opted for 2 inch as the cost increase was minimal.

3, Each company will talk up their selling points

4, My final two panels under consideration were the TechnoSolis and the Aquatherm Ecosun panels, in the end it was close to a coin toss, part of my decision was based on having a SW facing roof and I thought the flat TechoSolis panels might perform better than the rippled Aquatherm which might self shade during part of the day. Also I liked the fastener system for the straps better that is included in the TechnoSolis kit, but I am using the optional upgrade Aquatherm header clamps for the install also.

5, How many panels you need depends on multiple factors including how warm you want your water, simply put a person that wants their pool bath water warm will need more panels than someone that wants it crisp cool. I suspect in your location with full pool % coverage you will seldom if ever need the gas heat, remember no one ever got fired for selling the customer too many solar panels.

6, One potential selling point on the Aquatherm panel is they may perform better (expand / contract) when partly shaded which may put strain on a flat panel like the TechnoSolis, this is not a concern for me as my roof gets even illumination except then the sun is relatively low in the sky, I am not sure about the Heliocol.

7, From my past experience it is important to have a controller that senses panel and pool water temperature and turns the panel flow on when their is available heat / sun, I previously had a solar heater that was operated only by a timer, and ended up no only loosing chances to get heat, but would often loose heat to the cold rain from afternoon thermal thunderstorms.

8, Good luck with whatever you decide, I eventually let money be a big deciding factor once I had narrowed down my selection to a few quality brands. I could have paid 50% more for a panel that might have a slightly longer service life and slightly better performance, but once I stood back and gave things a fresh look it seemed such efforts to buy the best product regardless of the cost was foolish.

Ike
 
I just verified - the Heliocol is 2" also. Either the Aquatherm is bigger, like 2.5", or the Aquatherm guy had an old or different model sample of Heliocol.

Hadn't looked into TechnoSolis, but the 2 installers people recommended to me use Aquatherm and Heliocol.

The gas heater is for the spa. Don't plan to use that for the pool.
 
If it is 2 vs 2.5 inch then I would tend to say it does not matter as the flow restriction difference will be trivial. Remember optimal flow for most panels is going to be around 5 GPM per panel for most 4x? panels. I am not sure exactly where the flow resistance starts to go up for 2 inch pipe, but considering it is around 40-45 GPM for 1.5 inch, I suspect it is a non issue, bigger may be better to a certain point, but there are points of diminishing returns.

A couple of notes on the TechnoSolis panels, first they do not roll up for shipment like some of the panels on the market (see my message thread for a photo of the shipping crating solar-panel-replacement-update-t56572.html ) also when I unpacked them last weekend I was a bit disappointed on their build consistency, this is NOT a negative comment on overall quality as they certainly seem beefy enough, but there is just a bit more variation from panel to panel than I expected, in particular there is about a 1/4 - 1/2 inch variation in the placement of the end of the absorber panel in relation to the end of the header pipe (the stub on the header can vary in relative length), also the amount of extra plastic around the weld where header joins the absorber panel varies considerably (on some panels the radiator like hose fits almost flush, on others the excess fillet plastic pushes it back about 1/8-1/4 inch)

On a side note the Vortex panels that solardirect sells appears to be the 1.5 inch header version TechnoSolis panels mated with a cheaper installation mounting kit.
 
jblizzle said:
The more panels the more heat.

That's true only to an extent. Once the flow rate drops to a certain point, the thermal performance drops off significantly. If you have more panels than your pump can handle, you may see drastically diminishing returns from more panels. For most commercial grade panels, 2GPM is the "knee" on the curve where thermal performance starts to drop off quickly. Ideally you will need 4 GPM for typical 4x10 panels.

I agree wholeheartedly with the 2" vs 1-1/2" concept, especially for larger systems. You have to consider the system, not just the panel rating.

Jason Szumlanski
 

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In summary, it seems like a larger system should have 2" pipes. In this case both Aquatherm and Heliocol have 2" pipes (minimum). Most everyone is recommending to use my existing Aqualink panel, which also controls my gas pump (which I intend to use only for the spa) instead of the installer's separate controller. And I see nobody rushing to explain why they would pay more for Aquatherm Ecosun than Heliocol, so it seems that the Heliocol would be a better option for me.

Let me know if any of you have any additional thoughts. Also the amount of paneling I should get - if you have any suggestions, would be helpful. With 490 ft2 of surface area, the Heliocol guy first rec'd 400 ft2 of panel. I expressed concern, and he suggested another panel for 450 ft2, which he said he offered partly or largely because he thought it would make me more comfortable due to my questioning rather than to a benefit he saw. I get the feeling my installer(s) haven't installed systems with screen enclosures with extra heat blocking, so if any of you have any thoughts on if I should even ask for more than 450 ft2, please let me know. Thanks again to all.
 
haz said:
In summary, it seems like a larger system should have 2" pipes. In this case both Aquatherm and Heliocol have 2" pipes (minimum). Most everyone is recommending to use my existing Aqualink panel, which also controls my gas pump (which I intend to use only for the spa) instead of the installer's separate controller. And I see nobody rushing to explain why they would pay more for Aquatherm Ecosun than Heliocol, so it seems that the Heliocol would be a better option for me.

Be certain that the panels you are buying are, in fact, 2". The Heliocol dealer in my neck of the woods installs 1-1/2" header panels exclusively. As a solar pool heating professional, I'm not going to recommend a brand per forum rules, but common sense would indicate that a full-body panel would perform better than a separated tube panel. Wind = heat loss. I'll leave it at that.

Regarding the controller, the Aqualink is a very capable controller. All you need is a valve actuator and solar sensor along with a little programming. I can't think of any circumstance where I have recommended replacing a working Aqualink or using a separate solar controller. In fact, you will be able to heat your spa on a schedule or on demand with solar if desired and still use your gas heater on demand as well.

Jason Szumlanski
 
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Thanks. I didn't realize that one couldn't recommend a brand, even if your username is fafcosolar ;-) Fafco doesn't have installers in my area, BTW - interesting given that (according to a guy in Fafco corporate I once spoke to when trying to see why there wasn't an installer around here) South Florida is the first or 2nd biggest market for pools in the country.

I'll definitely have them hook it up to my Aqualink. Will save me $ with either installer too.

The dealer did email me saying 2" on his Heliocol panels. I realize that there is some extra heat loss and less efficiency per ft2 with the more open design of Heliocol. I realize there's diminished marginal returns on adding more panels, but I could get 500 ft2 of Heliocol for less than 432 ft2 of Aquatherm - my guess is that the heating difference would be at least eliminated. Also, I'm in a hurricane-prone area - maybe a plus for Heliocol, but probably it would be better to take any system down if a category 4 hurricane were on its way.

So, instead of saying that one panel is better than the other, I think there are enough people who've written here and on other threads saying that Heliocol panels do what they expect them to and are happy with them without significant complaints, so that's encouraging. I know people are happy with Aquatherm Ecosun too.
 
haz said:
So, instead of saying that one panel is better than the other, I think there are enough people who've written here and on other threads saying that Heliocol panels do what they expect them to and are happy with them without significant complaints, so that's encouraging. I know people are happy with Aquatherm Ecosun too.

Here's the "dirty little secret" in the industry. Virtually all panels perform great under ideal conditions, i.e. when the ambient temperature is relatively high and when the solar resource is great (clear skies). The key is how panels perform in sub-optimal conditions (cloudy, windy, cold ambient temperatures, etc.) Every manufacturer will cherry pick ratings that make their panels look better/best in marketing collateral. As I've said in other posts, it's not just the panel, it's the system that can make all the difference.

You are right - I'm sure that many people have Heliocol systems and are satisfied with the results. It all depends on how and when you use your pool and what are expectations are.

Regarding hurricanes, Miami-Dade County has some insane permitting requirements that definitely would seem to favor a separated tube panel, but that's not to say full-body panels can't meet FBC 2010 with ASCE 7-10 wind load calculations. In Southwest Florida we have design wind speeds of up to 172 mph. We don't even recommend separated tube panels except for certain roof types and when competitors have a potential customer convinced that full body panels are going to take their roof on a magic carpet ride (nonsense, by the way). Having lived through Hurricane Charley, Wilma, and others, I can speak from experience.

And BTW, my comments do not represent the opinions of any manufacturer, and I work for a dealer, not a manufacturer. I like to think that my advice is candid and fair. ;)
 
fafcosolar said:
jblizzle said:
The more panels the more heat.

That's true only to an extent. Once the flow rate drops to a certain point, the thermal performance drops off significantly. If you have more panels than your pump can handle, you may see drastically diminishing returns from more panels. For most commercial grade panels, 2GPM is the "knee" on the curve where thermal performance starts to drop off quickly. Ideally you will need 4 GPM for typical 4x10 panels.

I agree wholeheartedly with the 2" vs 1-1/2" concept, especially for larger systems. You have to consider the system, not just the panel rating.

Jason Szumlanski

I totally agree. My assumption was that you had the needed flow rate to support the panels, but did not make that clear.

Btw, thanks for your involvement in the forums. I think a lot of people can benefit from your knowledge.

Posted from my Droid with Tapatalk ... sorry if my response is short ;)
 
I am not sure about the Helicol attachment system, but if I were to even consider the idea of taking panels down if in the path of a hurricane I would take a strong look at Aquatherms optional header clamp http://www.sunsourceproducts.com/catalo ... &part=0218 which allows the headers / panels to be removed without effecting your roof penetrations.

I would also look at the speed clip style strap clamps like the ones techno solis uses (I think Fafco also has something similar, not sure who else) if the panels your considering use side straps http://shop.solardirect.com/product_inf ... cts_id=839

I suspect also that the radiator hose style connections would be quicker to remove with an impending storm, remember you will likely have very little warning, and very little help available when there is a storm on the way, so your ability to remove the panels within a couple of hours before the winds start picking up would be very important. Links were provided for illustration purposes only
 
For reference:

The Heliocol Gator Clamps that secure the headers are 2-pieces. The bottom is secured to the roof and the top half is secured to the bottom half. So they are removable without affecting the roof. These are the only clamps required as there are not straps that run across the panels.

Also the way the panels clamp together can be opened in seconds. They are a 2-piece clamp that wrap around the headers and locked together with a clip. Just pop the clip off with a pair of pliers and the clamp comes off and you are done. The "o-ring"/rubber band slips in grooves between the 2 panels. I have to think that is easier than using a screwdriver to loosen the hose clamp and then trying to pull the hose off (I have no idea how tight they are, but based on radiator hoses, it can be difficult).
 
Here is a picture of the Heliocol top header clamp on a shingle roof, and one of the unfortunate problems we see all too often. This is generally installation related, but there are some inherent problems with the design of the clamp. Conceptually, I love the idea. Not disturbing roof attachments during service is a definite advantage.
 

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I can certainly see that being a problem if only a single screw is used in each clamp and then only screwing it into the roof plywood (and not the rafters or a backing as the installation instructions state).

Additionally, those looks like the clamps to be used on the lower header. The upper header clamps do not have such a large gap as seen in the 2nd clamp.

If the install was done in the heat and the lower clamps were not installed with the recommend slack to account for contraction then I could see the panels contracting when getting cold and the tension pulling on the clamps.

In any case, I agree this looks like improper installation.

As a note, my roof is nearly flat, and I did not use any screws. I used roofing cement to anchor the lower half clamps. We have had a few good bursts of wind without any apparent problems. I suppose there is a chance that the panels and clamps could lift off and rip the roof coating off, but with the open design of the tubes, I am not too concerned yet.
 

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