Jump to content

Solar Collector Advice


Jabba

Recommended Posts

I have an in-ground swimming pool that currently has solar collectors on the roof of the house. There are 11 collectors that are approximately 4x5', and they are constructed of of individual 1/4" hoses (similar to drip irrigation hoses). The collectors are quite old and many of the hoses have sprung leaks. I've repaired lots of them with drip irrigation fittings, but I think the collectors have about had it and I feel like that kid that keeps poking his fingers in the dam to stop the leaks.

Photo of existing collectors:

20090104-IMG_6451.jpg

In the spring I'd like to demo the existing collectors and put up a new set, so I'd like to get some advice on which brand. The ones I have now seem quite cheap and prone to deterioration and breakage with all the individual tubes, and there's quite a lot of pvc/abs, collectors (11), brackets, etc. to make what seems like a somewhat complicated and visually unattractive system.

In their place I'd like to have something that looks a bit nicer, is more durable and just as (or more) powerful. I came across these Vortex 4x12' Collectors that look pretty slick. They're a polypropylene plastic extrusion so they appear virtually flat across the top of the collector, but have elliptical tubes on the inside. They also come in 4' wide collectors, while a lot of the others I've come across are 2' wide so you have to connect more together to make up the same sq ft. To me the Vortex seem more durable with this plastic extrusion, I think they'll look better with the flat surface, and I also think a lower number of 4' wide collectors across the roof will look better and offer a simpler install with lower number of failure points.

Sungrabber seems like a popular brand, but they have 2' collectors and the surface appears to be ribbed where the tubes are fused or molded together. Although I think I did read somewhere that the curvature of the tubes can collect more sun since part of the tube is always facing the sun as it arcs across the sky. Not sure if there's any truth to that.

So please give me some feedback, and anyone who has experience with these Vortext collectors please let me know. They seem to only be available from Solar Direct and are a couple hundred bucks more than the Sungrabber.

Link to comment
Share on other sites

You can check out solar thermal collector ratings for pools here where you can see that Fafco panels have a very high rating. Vortex isn't listed. By the way, you wouldn't use SunGrabber panels on your roof (those are usually near the ground for above-ground pools), but would either use SunSaver or Revolution, both of which have 4' widths and either 8', 10' or 12' height.

I've had Fafco panels on my roof for 7 years now with no problems. Some people like Helicol better so there's clearly personal preferences involved based on specific installation circumstances.

Link to comment
Share on other sites

In my area, Fafco panels are popular. You can get them in different sizes too. 4' X 8', 10', and if i'm not mistaken 12' as well.

DON'T fall off the roof next spring.

Well I'm in S. San Jose, so not far from you. Do you recommend a local retailer where I can purchase them?

Thanks.

Link to comment
Share on other sites

  • 4 months later...
You can check out solar thermal collector ratings for pools here where you can see that Fafco panels have a very high rating. Vortex isn't listed. By the way, you wouldn't use SunGrabber panels on your roof (those are usually near the ground for above-ground pools), but would either use SunSaver or Revolution, both of which have 4' widths and either 8', 10' or 12' height.

I've had Fafco panels on my roof for 7 years now with no problems. Some people like Helicol better so there's clearly personal preferences involved based on specific installation circumstances.

Reviving an old thread here. Getting close to purchasing solar collectors. Naturally I turned to the internet first. I've been leaning towards Fafco, and the Sungrabbers are sold in a few places online for a reasonable price, free shipping, no tax, etc.

You mentioned that Sungrabber are typically for above ground, however I see them advertised as both, and the online retailers seem to advertise them mostly as in ground application. Is there typically a difference in the construction, sizing (i.e. 2' vs 4' width) or otherwise for in/above-ground collectors?

Sungrabber seems to be made by fafco, but advertised and sold as its own brand, and is more readily available online. Can someone tell me exactly what the difference is between these and say the Fafco sunsaver collectors?

Finally, collector size and orientation. I see most installations as vertical 4' x 10/12' collectors. My roof is approximately 28' width by 18' height with a normal (not too steep) slope. A horizontal installation of 2' x 20' (sungrabber) seems to have a better cost/value. E.g. 8 - 2' x 20' collectors would yield 320 sq. ft. of surface area, which would require 13 - 2' x 12' collectors. It seems sunsavers come in a max 4' x 12' size, so I guess I'd have to go with a vertical installation with a higher cost. So, vertical vs. horizontal?

Thanks for the info.

Link to comment
Share on other sites

I may be wrong about the SunGrabber. It looks like it's the Solar Bear for above-ground pools. So long as your SunGrabber installation includes a pressure relief valve and automatic draining, then you should be OK. The Revolution and SunSaver are rated here, but other Fafco models are not so check the specs as they may not be as efficient (you generally get what you pay for).

Link to comment
Share on other sites

Most panels can be mounted either horz. or vert. Plumbing is key. Take your panel and draw an imaginary diagonal line from a lower corner to the opposite upper corner. Thats how they need to be plumbed. If thats confusing, think of it this way, the water MUST cross the panel vertically, as well as horizontally.

Link to comment
Share on other sites

Thanks for the feedback. The SunGrabbers I'm looking at do include the relief valve and roof mounting hardware.

So there doesn't seem to be any advantage/disadvantage to mounting horizontal/vertical?

Regarding the plumbing, I think I understand the flow with the supply entering at the bottom corner, and the return leaving at the top opposite corner. WRT to drainage, my old system had the relief valve and all, but I think it was plumbed in a way that it never drained. The pool is in the back, the panels were on the front of the house. The supply and return pipes travel up the back wall of the house, then up the slope of the back part of the roof to the ridge, then back down the front where they connect into the collectors - supply on bottom left, return at the top right. It seems like the return pipe itself would rain, but I don't see how the collectors would drain as the water would have to run "up hill". Perhaps the water would siphon out the return pipe, with the VRV allowing air to enter the collectors. But I can't believe this would allow all the water to drain?

How does drainage work on a typical system? If my pipes travel over the ridge of the roof like this, will drainage work property for me?

Thanks.

Link to comment
Share on other sites

On those types of installs, you wouldn't (really)need to drain the panels till you close them for the winter at which time you would pop one of the plugs at the bottom and let them drain. If you want to get fancier, incorporate a hose bib into the plug, so all you have to do is open the bib.

Link to comment
Share on other sites

  • 2 weeks later...

On those types of installs, you wouldn't (really)need to drain the panels till you close them for the winter at which time you would pop one of the plugs at the bottom and let them drain. If you want to get fancier, incorporate a hose bib into the plug, so all you have to do is open the bib.

Just want to confirm the configuration of the plumbing up onto the roof. I was planning on just running new pipes based on the old configuration:

old-panels.png

Should I just plumb the new pipes the same way? Or should I run them along the W side of the house and then up the wall so they don't have to travel over the ridge?

And why is drainage not really a concern on this setup? Is it mostly a concern with freezing, which we don't get in SJ during swim season of course. What about the extra weight always sitting on the roof?

Thanks.

Link to comment
Share on other sites

If the current configuration has worked in the past, i would keep using it. Moving the plumbing like you suggest is a lot of work, and i don't know if you would get that much improvement from a re-plumb other than being able to drain out the panels each day when the pump shuts off, and maybe a little better flow.

Draining the water out of the panels is pretty much for winterizing. If you have two isolation valves for the solar, you would want to leave the hose bib (i talked about earlier) open through the winter to keep heat pressure from building on sunny winter days.

Link to comment
Share on other sites

  • 5 years later...

I think its very tough decision for an individual to choose perfect solar collectors for their swimming pool who don't have any knowledge about all these stuff, my personal advice for you is to consult any Solar services provider and ask them for help.Please don't take any decision without an expert advice.Buy solar thermal collectors after checking their ratings.Check out their advantages & Disadvantages before purchasing them.Any professional solar services provider can provide better advice regarding choosing panels.

Link to comment
Share on other sites

  • 4 years later...

I have had six Vortex 4x12 panels on my roof for 12 years.  They are starting to leak at the header joint. The leaking started at about the 10 year time, when the warrantee expires.  The leaks are very fine cracks in the header joint.  I have been able to patch with ABS cement. However the panels are very sturdy and have survived high winds very well.  I will probably buy another set if the repair problems become too great.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...