Note: The information contained in this periodical weblog may be outdated. This was my personal weblog published before January 1, 2015. Since then I have been the co-owner and Principal Solar Designer at Florida Solar Design Group.


  1. There are more variables to compare when it comes to solar panels besides BTU ratings. FAFCO strap system requires adjustments every 1 to 2 years. It also requires more holes in the roof (more potential to roof leak problems). Piping requires hoses with metal clamps. On the other side, HELIOCOL panels eliminate all these maintenance issues. Panels require less than half the number of roof penetrations. Since the panels are not 100% in contact with the surface of the roof, it keeps and maintains the roof cleaner and drier. And when it comes to hurricanes, I rather prefer to have less wind resistance than helping the roof to come out by a big giant sail. It is the truth that FAFCO is superior than HELIOCOL in BTU ratings, but if they both get the job done then I want to keep my roof healthier.

    1. Charlie,

      Thank you for your comments. Your assertions are just perpetuating additional myths about FAFCO solar panels. These arguments are related specifically to the FAFCO Revolution and Sunsaver panels, which are ‘flat panel’ or ‘full body’ panels. The arguments are completely irrelevant against the Sunsaver ST panel, which is similarly a ‘separated tube’ design. The wind load characteristics of a Sunsaver ST panel are exactly the same as a Heliocol panel.

      Regarding the Revolution and Sunsaver panels, these solar collector systems are engineered to use top straps to keep solar panels in place in the event of uplift caused by wind. This is not exclusive to FAFCO panels – other flat panel manufacturers have the same requirements. In Southwest Florida, we have required design wind speeds in various jurisdictions extending up to 150 mph, and all contracts representing ALL brands must adhere to the same requirement. This engineering is required for building code and permitting. The roof attachments are engineered such that the minimum pull out strength of the attachments exceed the wind load requirement (plus a safety factor).

      To say that the panels act as a “giant sail” is a common talking point by the competition, but it is completely ridiculous. The roof is going to come off the building before the panels come off the roof. Otherwise, the panels may be destroyed by windborne debris, which applies to all panel types. And, yes, they are covered by your homeowners insurance.

      Again, this is a non-argument against the Sunsaver ST panel, so if you are still unconvinced, you have an option for a FAFCO separated tube collector that still beats the Heliocol in terms of performance.

      Tighten straps every few years? All I have to say is “what are you talking about?” We run a service department like all solar contractors, and I can’t remember hearing this request in my tenure more than a few times. This is a request likely resulting from not tightening the straps enough from the start, which is sometimes difficult to do, and it’s a simple fix normally done free of charge when under warranty.

      Don’t get me started about the ridiculous arguments against the FAFCO Dacron straps, another myth propagated by the competition. They use unforgiving coated stainless steel straps. Coatings don’t last, and steel does not do well against plastics. It’s a silly argument.

      I can’t wait to get in the office this week. I will post some pictures of roofs after FAFCO panels are removed. The roofs are CLEANER and in BETTER repair than the surrounding roof. Solar panels tend to protect the roof below, not damage them. In fact, separated tube designs tend to trap leaves and debris and cause more staining than flat panel collectors. Even then, the ‘damage’ is cosmetic.

      I do agree with one issue you presented. The FAFCO flat panels (Revolution and Sunsaver) do require straps that increase the roof penetrations. However, whether your system requires 15 or 50 penetrations, proper workmanship results in absolutely no problems. This is a non-issue. The fact is, all solar contractors penetrate your roof (except on some metal roofs), and the number of penetrations does not increase the risk.

      We’ve had hurricanes through Southwest Florida recently (Charley, Wilma, et al) and I speak from experience. The wind load comparison by FAFCO’s detractors is complete bunk.

      Once again, I appreciate your comments, but they sound like the same old sales junk that frustrates me every day. I’m not sure if you work for the competition, or have fallen victim to their propaganda, but I respectfully disagree with you. Thousands of local residents who enjoy better performance would also agree.

  2. Here is a picture showing how FAFCO solar panels keep roofs clean – not the opposite. We removed these panels recently, and the tiles where the panels were located are clearly cleaner than the surrounding tiles.

    Anyone who tells you that FAFCO panels cause dirty, wet, or rotten roofs under the panels is just plain wrong. The only thing dirty is the dirty sales tactic.

    Fafco Solar Panels Keep Roofs Clean, not dirty as some would suggest.

    Here’s another on a Barrel Tile Roof after removal:

    Clean Roof!

    And here’s one on a shingle roof. The shingles have the original color where the solar panels were located.

    Clean Roof!

  3. Just curious since I am thinking of having a system put in…I’m wondering if the Sunsaver is superior Heliocol, why did Fafco mimic Heliocol’s individual tube design with the ST series?

    Also, has Fafco or Heliocol ever had a major recall on their panels. seems like Fafco had some issues awhile back if I remember correctly. I looked up the SRCC OG100 ratings on both Heliocol HC and Fafco Sunsaver and against your claims the HC has a higher btu rating than both the Sunsaver and ST, only the Revolution matches but does not exceed the HC.

    Either way, in my area in Oregon my only options are the Sunsaver and HC. What do you think?

    1. Lou,

      I’m not sure where you are getting your data, but all of the FAFCO panels (Sunsaver, Sunsaver ST, and Revolution) all outperform the Heliocol HC panels. Look at the OG-100 rating sheets:

      FAFCO Sunsaver:
      Heliocol HC-40:

      The FAFCO Panel has identical Warm Climate (Category A) BTU thermal performance ratings as the Heliocol. You will also notice a few peculiarities about the SRCC OG-100 ratings, which are done with tests conducted to either ASHRAE or ISO standards. The FAFCO panel’s test flow rate is half that of the Heliocol panel at 0.595 gpm/ft^2. That flow rate is also 40% lower than the manufacturer’s recommended flow rate. Of course the rating will be lower because the panel’s efficiency at half the required flow rate is far lower!

      Where the FAFCO panel really blows away the competition is in cooler climate (Category B). See for yourself how much higher the ratings are in Category B.

      FSEC’s test procedures are done with a single standardized methodology and the flow rate is at the manufacturer’s recommendation of 4 gpm for a 40 sq ft panel (0.10 gpm/ft^2). Again, FAFCO’s Sunsaver BTU ratings blow away the Heliocol HC ratings.

      As the temperature decreases and the temperature differential increases (Ti-Ta), The FAFCO panels really start to shine and perform well above the competition’s panels.

      The Sunsaver ST separated tube panel was designed to compete on an apples-to-apples basis with the Heliocol HC product, and has similar thermal performance characteristics. There are some markets and some applications where this panel is a better choice, and it is often a lower cost option. However, there is no comparing a full body panel’s performance with a separated tube model. The full body panel will always win the performance race. You do get what you pay for!

  4. Lou, to answer your questions specifically, I am not familiar with the solar market in Oregon and I suggest you seek reputable dealers in your area. I don’t want to create the impression that your market is the same as the Florida market in which I have experience. There may be other factors in play of which I am not aware.

    That being said, my numbers are accurate. I’m just repeating what the independent testing agencies say about the panels.

  5. jason, i’ve found your comments to be very informative. i’m in southern california and when i talked the dealer who uses fafco, it appears he uses the sunsaver ST almost exclusively. Your information is based on your experience, which is obviously with full body panels.

    Is there then a significant difference between the separate tube designs between fafco, heliocol and even sunstar?

    thanks for the info!

    1. Tom,

      The most important factor that differentiates FAFCO from Heliocol in terms of the separated tube panels is the header and plumbing size. Even the Sunsaver ST model from FAFCO uses 2″ headers. Heliocol uses a 1.5″ header and most Heliocol dealers use 1.5″ plumbing, fittings, and valves throughout. My article details the disadvantage of this plumbing size. All new residential pools are built with at least 2″ pipe as far as I know. Why would you want to introduce smaller plumbing into an existing circulation system?

      Another nice feature of the FAFCO panels is that they are made right here in the USA (Chico, CA). Heliocol’s panels are made in Israel by Magen Eco Energy, a separate, but related company.

      Below are a few talking points from FAFCO:

        Patented Flow Metering System – Provides better heating performance.
        Patented “Sure Seal” Coupling System
        Crafted At Our State-Of-The-Art Manufacturing Facility
        Made Of Durable, Lightweight, Ultraviolet-Resistant Polyolefin Material – With blended proprietary additives.
        Manufactured In USA – Under exacting, quality control standards.
  6. I have an old FAFCO system. I believe the header is 2.00 OD, 1.68 (1-11/16″)ID. Will a replacement FAFCO Rev, SS, ST work or do I need to get an off brand to mate up properly?

    1. Bill,

      It sounds like you might have a FAFCO Sungrabber panel which is an economy panel made for above ground pool primarily. They have 1-1/2″ nominal headers and are not compatible with a Sunsaver, Sunsaver ST, or Revolution panel. Are you panels 2′ wide by chance?

      I’ll send you an email and hopefully we can identify your panels and help you out!


  7. Jason,
    I’m in New York and one of the dealer suggested using FAFCO SunGrabber(1-1/2) for my IG pool. Is this the right thing to do?


    1. Typically the Sungrabber is indicated for above ground pools. You should look at the Sunsaver ST, Sunsaver, or Revolution panels for your in-ground pool. Local conditions may provide some reasoning for the Sungrabber, but I doubt it. I would question whether this is the right choice. The dealer may not offer alternatives, so that could be the reason… I’m located in Florida, so my experience is limited to warmer climates. I suggest you contact Fafco, Inc. in California for an answer from the manufacturer…

  8. Hi Jason

    I have found your information to be very helpful.

    I just purchased a home in Castro Valley, CA. This is on the east side of the San Francisco Bay. I currently have old, leaking Fafco solar collectors on the north side of the roof. One out of five has been disconnected due to leaks. I have corrected the the short circuited plumbing arreangement and installed a VS pump for efficiency. An added benefit of the VS pump is the leaks are not as drastic due to decreased pressure. I will be replacing the entire solar system next spring on the south and also possibly west side of the roof. My pool is 550 sq. ft. and I am looking to maximize my season as long as possible.

    I have questions related to the configuration, price, flow and required surface area of the system. In order to take advantage of the shape of my roof area, I think I will have to use 8, 10 and 12 foot panels. Can you give me a ballpark price on just the panels and which one is best to use so I can start planning a budget for this project? It seems as though the larger panels should be more economical with respect to output versus price. Fafco recommends 4 gals/min as an optimum flow rate. Am I correct in assuming that with each panel I add I should increase the flow accordingly? If I use the south side of the roof only, I can fit six 8′, five 10′ and one 12′ panel for a total of 440 sq. ft. If I use the west side as well I can add three 12′ panels. Its seems to me this would be necessary to maximize my season. wWhat are your thoughts on my reasoning and the Sunsaver versus Revolution panels for this application?



    1. Matt,

      You will want to contact your local dealer, Diablo Solar ( I work for a dealer in Southwest Florida, and our pricing will be different. We deal with high wind codes and a different environment. We are only a dealer for FAFCO, Inc.’s products.

      Incidentally, FAFCO is in your back yard, manufacturing panels in Chico, CA.

      Generally speaking you are correct. More panels equals more heating performance. I can’t speak for other dealers, but it is more economical to install larger (longer) panels in our market.

      Regarding flow rates, you multiply the number of panels by 4 to get the required GPM. You can go a bit lower. The performance curve does not drop off precipitously until you get to around 2 GPM per panel. With a Variable Speed pump we typically install a flow meter and dial in a speed that achieves 4 GPM/panel and eliminates bubbles in the pool and fully engages the vacuum relief valve, then add about 200 RPM to account for the filter getting dirty and reducing flow.

      Lower pressures with a VS pump may extend the life of your panels. Great move installing the energy efficient pump!

      As for the upgrade to Revolution panels, the BTU ratings are published, but the performance increase will vary based on the ambient/operating temperature. You will have to make a judgment call based on price and warranty. The Revolution warranty is an industry leading 15 years!

      Again, your local dealer can advise you best. Your current panels should have a 12 or 15 year warranty. That’s a long time without worries about leaks! If you are in the warranty period, give your local dealer a call for service.

  9. Thanks for the referral to the FSEC website with their very useful data. Why don’t they have high temp data? Our roof panels in HI can get up to 212F on some days.
    Also, what data do you have on drops in btu/ft2 under windy conditions? My solar contractor feels that the Fafco will loose less heat on windy days than the Heliocoil models.
    Also, how do the warranties compare?

    1. Panels are rated at low, intermediate, and high temperature. Pool heating panels typically operate at the low temperature rating. That’s because you have relatively cool pool water running through the panels. The temperature of the roof is not the issue. If you run hot water through the panels, they become essentially ineffective (can’t heat any more) so there is no useful data at the high temperature range. Focus on what’s important – the low temperature rating – after all, you are trying to heat water that is at too low of a temperature!

      I don’t have any solid information on wind’s effect on BTU output, but anecdotal evidence and common sense tells you that a solid body panel will perform better at heating water in windy conditions. FAFCO actually has a separated tube panel, but it performs more like the competition’s split tube panel – more evidence that split tube designs are simply not as effective. Your solar contractor is definitely right.

      Warranties are basically the same unless you go with the Fafco Revolution panels, which carry an industry leading 15 year warranty. Heliocol dealers love to make a big deal about the fact that FAFCO does not cover parts other than the panels. What they don’t tell you is that those parts do not generally fail. FAFCO does not manufacture some of the parts like the hose couplers and stainless steel hose clamps (which you might hear a Heliocol dealer call a “radiator hose and metal clamp.”) Both companies cover the main potential failure points well. In practice there is little discernible difference.

      Hope that helps!

  10. Hi, Fafco Solar panels are either good or better. The only criticism I have of Fafco is the subheader. It can clog with DE. This is a fact. You can not deny it. I’ve cut open headers and found tubes clogged solid.
    I’ve been doing pool solar since 1976.
    Yee haaa. Well. Oh, my aching back!!

    Much aloha,

    1. No denial here. DE can clog any panel, but the subheader may be more susceptible. We advise switching to a cartridge filter. There’s no good argument against a quality cartridge filter in Southwest Florida. DE is a pain and messy.

      I’ve never seen a tube clogged solid, but sometimes there is a lot of buildup at the opposite end of the lower header from where the feed plumbing comes in.

  11. I still find systems installed by my competitors that can’t drain out. This is great for me but bad for the industry. I get to fix the problem (freeze repair and in worst case, panel replacement and redisgn panel lay out, and make the money. Some systems don’t ever get fixed and get trashed.

    1. System draining is critical to avoid freeze damage, even here in Southwest Florida. Sometimes it’s impractical to install a system to drain (due to plumbing distance, gable roofs, etc.) In those cases we typically install a manual drain valve and/or use automation products’ freeze protection capabilities to circulate water during freeze conditions. Unfortunately, manual drains get forgotten and automation doesn’t always work perfectly (power outages are common during freeze conditions around here). Technically, manufacturer’s operating instructions require that the homeowner winterize panels to prevent against freeze. Buyers say they will follow the winterizing process to reduce the cost of drain lines or automation. Ideally the end cap on the feed line is removed any time freeze conditions are likely and the panels are verified to be drained fully. This is rarely done in practice. Freeze damage is a frustrating thing for dealers and owners alike, but easy to avoid with good design and conscientious owners.

  12. Im in central florida and cant decide between aquatherm’s solar industries or fafco. They seem to be about the same when compared on the srcc in cool climate which is when im most interested in heating the pool as i wont need heating in the summer. Any advise?

    1. You are correct. FAFCO panels have a slight advantage per the SRCC ratings. If you look at the FSEC certification ratings, you’ll see a slightly larger advantage. You will want to consider more information. What’s critical is how the SYSTEM works. Because of the patented subheader, you should expect more even flow rates with the FAFCO system. The collector ratings only show the single collector performance under test conditions. There are several other factors, but it’s best that you contact your local dealer and have them out to look at your particular application.

      I can probably help you find your dealer, or you can use FAFCO’s dealer locator at:

  13. Jason —
    I’ve been scouring the web for reliable information about solar pool heaters and it is tough to come by. I really appreciate your taking the time to answer everyone’s questions. Your answers are very helpful.

    I live in the Miami area and am thinking about installing a solar pool heater, but I have a few concerns. The first is my roof. You responded in one of your previous answers: “all solar contractors penetrate your roof (except on some metal roofs)” — I have a metal roof. If I were to buy a Fafco system, would it be necessary to penetrate my roof? If so, won’t that impact my roof warranty? I built the house about four years ago and I’m not sure I’m willing to trade my roof warranty for a warm pool.

    Thanks in advance.

    1. @Ray,

      Excellent question. There are many types of metal roof, and many ways that attachments may be made. Your local solar expert should be able to advise you based on local requirements. If you have a standing seam metal roof, one solution may be an “S-5! Clamp.” These clamp on the to seam of the roof with no penetration of the metal. These may or may not meet the local building code in your area.

      S-5! Clamp

      On the other hand, if you have a 5V metal roof, also common in Florida, the only choice is to penetrate the roof to attach a solar pool heater. The good news is that this is one of the easiest roofs to penetrate and maintain waterproof integrity. A watertight seal between the flat surface of the roof and the anchor hardware is very reliable. A variety of attachment methods are available, and your solar installer should be able to work with the roofing manufacturer to ensure the warranty will be maintained.

      One solar hardware manufacturer that claims their product does not void most metal roof warranties is EcoFasten Solar. They make a product called Simple Seal that uses an EPDM gasket to maintain a waterproof seal. ( When using this product, the solar pool heating system must be installed on an aluminum rack, which does increase cost, but may provide the peace of mind you seek.

    2. @Ray,

      FYI, a 5V metal roof has exposed fasteners and looks like this:

      5V Metal Roof

      A standing seam roof, which may also be called a snap-lock panel, has no exposed fasteners and looks something like this:

      Standing Seam Roof

  14. Within a few days I will give the go ahead for either a Sunstar system Fafco system. The Sunstar rep told me that the Sunstar is the next generation after the hiliocol panel you have been describing. Can you give me your comparison between your Sunsaver ST and the Sunstar Panels? Also, rep is touting a 12 year parts AND labor warranty including damage from freezing. Thats pretty compelling! I can’t find a copy of your warranty anywhere online to read the ‘fine print’. Your prompt reply would be appreciated. I live in central florida…

    1. Yep. Sunsaver panels have a 12 year warranty. The manufacturer reimburses the local dealer for repairs or replacements to panels. The dealer may have nominal charges for trip or diagnostic fees. I’ll have to email you a warranty copy from the office tomorrow morning, but there aren’t any surprises. Freeze damage is covered as long as the system is installed properly – that is, to drain fully when the pump is off. Panels don’t freeze if they don’t have water in them. Pretty simple concept.

      You will find most manufacturers have similar warranties and some dealers will try to cast doubt about the competitors’ warranty coverage. It’s all nonsense. I can speak from experience that FAFCO has never rejected a legitimate warranty claim that we have submitted as a dealer.

      Just like your existing pool equipment, it’s possible but unlikely that something else could go wrong that is not a manufacturing defect, and not the fault of the installer. Any plumbing exposed to the elements that sees literally millions of gallons of water passing through in its lifetime may be subject to minor repairs. However, all manufacturers generally cover all major (expensive) components. Warranty should be the least of your concern from a competitive standpoint.

      Enjoy your new FAFCO Sunsaver system! You’ll be swimming well before and after your neighbors each season, and will enjoy your pool so much more!

  15. Thanks Jason – I appreciate your prompt reply about the warranty situation and look forward to getting a copy of it from you via email. However, I was also interested on the major pros and cons of the Sunsaver ST vs Sunstar panels with respect to performance and features. I’ve already met with the Sunsaver rep and I’m actually meeting with one of your Sunstar Reps later today, but would also appreciate your perspective..

    1. Ted,

      I just realized that I didn’t address you question directly, and I apologize for that. When looking at solar pool heating options, one of the most important factors to consider is total system performance. We focus a lot on the collector performance, and that is important, but it’s only part of the story. We FAFCO dealers love to talk performance, because we happen to have the best performing panels in the industry (FSEC and SRCC ratings). It’s also important to look at how the panels perform in conditions in which you will need solar pool heating most. Some manufacturer’s like to cherry pick specifications that favor their panels, which often tell you how a panel will perform in the dead of summer, when you don’t need heating performance.

      Anyway, the number one feature of the FAFCO brand is the patented subheader. Others will tell you that the subheader clogs up or creates “back pressure” on the pump and destroys it. It’s nonsense, plain and simple. FAFCO panels do have slightly higher resistance to flow, but at the flow rates typical in a solar pool heating system, it’s only a couple of PSI, which is inconsequential. The major benefit is that the flow among the tubes and the panels is balanced. You get more even flow throughout the system, improving heating performance greatly on a system level. Again, the panel performance is only a piece of the puzzle. You have to look at solar pool heating as a system.

      You will find other manufacturer’s touting the advantages of an “over-molded” header design and warning against welded header designs. The truth is that FAFCO has perfected the panel welding process, there are no significant panel weld issues to worry about, and the collectors are covered under warranty anyway. There are no advantages of an “over-molded” design, and they do not have the flow balancing features of the FAFCO patented subheader.

      The FAFCO SunSaver ST generally all of the same other features of competitors separated tube designs and similar panel heating performance. I can point to the flow/system advantages, but to step up to a different level of heating performance, you need to go to a full-body design like the FAFCO SunSaver or Revolution panel.

  16. Jason

    Thanks for your additional comments…

  17. Jason,

    You said there is no comparing a full body panel to a separated tube panel. How then does your Sunsaver ST panel match up against Solar Industries new Ultrasun panel which has two inch plumbing and is a full body panel?

  18. Maybe it’s more fair to compare it to your Sunsaver panel?

    1. Bob,

      The comparison to the ST panel is definitely not apples-to-apples. You are correct that a more fair comparison would be the Sunsaver. However, the most fair comparison would be FAFCO’s top rated product, the Revolution panel. The Revolution remains the highest rated panel on the market based on FSEC and SRCC testing. These are the only apples-to-apples comparisons that you can make, as they are the only two testing labs that have evaluated both brands. The Sunsaver and Revolution both beat Solar Industries’ top rated panel, although be a narrower margin than the comparison to any separated tube like FAFCO’s ST or the Heliocol panels.

      Regardless of any standardized ratings, virtually any full body panel will beat a separated tube panel hands-down under practical conditions.

  19. I have a slightly elevated Heliocol solar collector,, ground mounted. Yearly my pool man can not get all of the water out of the collectors and I have broken solar collector tubes as a result. The lowest level of the collector does appear to be either level with the pool water when drained for winterization or when the pool is filled definitely below the water level. Is this an installation error? My question is why can’t the pool man properly winterize the collectors to prevent the tubes from breaking. Is there a back flow to the tubes when he blows the water out of the lines? He says he can’t blow all of the water out of the solar collector lines. Should certain drain valves be installed to prevent this condition?

    1. Patricia,

      There is no reason that you shouldn’t be able to completely evacuate all water out of solar collectors for winterization. Solar contractors normally should install bypass and isolation valves so the system can be completely disconnected and drained. Manual drain valves can be installed at the lowest point where water can be trapped for ease of winterization and service.

      I can’t say that it was and “installation error,” but it sounds like it was installed in a manner that makes it hard to service. Some dealers will cut corners to save cost, installing a poor system of valves or eliminating them altogether.

      Note: in southern Florida, we often use pool automation products to handle freeze control duties because the winters are mild. This may not meet the requirements of all manufacturer’s freeze protection warranties, however.

  20. Jason,
    I just had 8 Fafco sun saver panels with a intelliFlo variable pump and a solar touch controller. They set the pump to run at 2800 RPM. I’m picking up around 2 degrees. The top of the outlet header is about 18 feet head. The pipping is all 2″ ID. Is there a rule of thumb RPM per panel. I’m thinking of playing with the speed a little at a time. The panels had to be on the East morning sun side of roof in Venice Fl.
    Thanks for all the info from your site, Howard

    1. Howard,

      Optimum flow rate for FAFCO’s SunSaver pool heating panels is approximately 4 gallons per minute per panel. Based on your email address, I could not find you in our database, so someone else probably installed it.

      I would really need more information, like the pump outlet and vacuum pressure, to determine your flow rate based on the pump’s performance curve. We like to install a flow meter (FlowVis) to “dial in” the optimum flow rate. This is the best way to balance pool heating performance and energy savings with a variable speed pump.

      To answer your question directly, there is no real rule of thumb. 2,800 RPM sounds a bit high, but it really depends on your plumbing. Some older pools and certain features create high back-pressure and require higher speeds to reach desired flow rates. Be careful to not exceed the capability of your pool’s existing plumbing in terms of water velocity. Your local dealer should be able to help you optimize performance.

  21. I am looking at 3 to 4 different installers and panel systems, Fafco, High Tech and Swim Master.
    Where can I go to get an unbiased comparison to these different panels? You are affiliated with Fafco so not sure how unbiased you can be.


    1. John,

      You will have to rely on reputation for a subjective comparison in general, and this applies to the dealer and the panels. If you are looking for objective comparisons, the de facto standard for testing is the FSEC rating, and these can be found on FSEC’s website here:

      You may also wish to look at SRCC ratings, which provide three categories of thermal performance. These ratings are found here:

      The SRCC ratings are important because they show how collectors perform as conditions deteriorate (i.e. when you need solar pool heating the most). Some unscrupulous manufacturers and dealers will cherry pick SRCC ratings that appear to make their collectors higher rated. The important factor is how performance changes as you go from Category A to B, and even to C. As a convenience, I have included links to all four SRCC sheets for you. Also, below are images of the important SRCC section on each sheet. You will notice that the FAFCO panel does perform the best under Category B – pool heating cool climate – when it matters most – and under all irradiance levels. Of particular note is how poorly Heliocol’s panel performs in sub-optimal conditions. Their separated tube design is inherently less productive as the ambient temperature decreases relative to the pool temperature, and wind is especially problematic. In fairness, FAFCO does offer a separated tube option, but this is not the panel you are talking about. Solid body panels offer dramatically better heating performance. Tube-on-fin designs like the SwimMaster and Hi-Tec perform second best. Welded tube designs offer the most heating performance. It’s common sense, and the test results prove it.

      Note: SwimMaster and Hi-Tec have similar performance test results, and they are made by the same manufacturer. They are both tube-on-fin designs.

      FAFCO SunSaver
      FAFCO SunSaver SRCC

      Heliocol SRCC

      SwimMaster SRCC

      Hi-Tec SRCC

      SRCC Data Sheets:
      FAFCO SunSaver

  22. One more clarification to John: I am affiliated with Fafco Solar, an independent dealer of products manufactured by FAFCO, Inc. While that does no eliminate bias, I wanted to make it clear that I am not affiliated with FAFCO, per se.

    I think you’ll find my blog articles pretty fair. In fact, you may want to read my recent post comparing pool heating options in Southwest Florida – solar isn’t best for everyone, and I’ll tell you why!

  23. Jason,

    First thank you for all the great information. I have been reading this blog and the Q&A has really helped me to understand technology and the process.

    I live in Northern NJ about 20 miles NW from NYC. Unfortunately there aren’t any fafco dealers here in North Jersey the only one I see in my area is about 3. 5 hours away in Stone Harbor New Jersey which is basically at the very southern tip. What can I do? I don’t want to get just any person to try and install my system and find out they didn’t do things correctly. You can email me and maybe we can talk on the phone?

    Thank you.

    1. Unfortunately, Darren, you will have to call FAFCO, Inc. in Chico, CA to get some advice on how to proceed if you do not have a local dealer. There is a good installation manual, but you will probably need a contractor licensed in your state to do solar energy installations. In Florida, plumbers and pool builders are licensed to do this kind of work, but as you mentioned, you don’t just want anyone to do it. It is a multi-discipline specialized trade.

      I wish I could be more helpful.

  24. Jason quick question the dealer in my area likes the Sun saver as opposed to the revolution could you please enlighten me between the two and is it a big difference in price and quality.

  25. Darren,

    As of January 2014, the Revolution brand solar pool heating panel is no longer available from the manufacturer. The SunSaver is within a few percentage points in terms of performance. The price was more than a few percentage points greater, so as long as you have enough roof space, you won’t find yourself at a disadvantage. In other words, the SunSaver provides the best cost/performance value.

    From a construction standpoint, the Revolution was very similar to the SunSaver, except for specially developed dimples that cause turbulent flow within the tubes. Otherwise, they have the same physical dimensions and are interchangeable within a system.

  26. Jason,

    Excellent information. So does that make the Sunsaver the best panel that Favco produces? I’ve gone to their website but very little specific information on panels.

  27. Yes, the Fafco Sunsaver is the industry leader in terms of thermal performance.

  28. Jason, many thanks again for all the excellent info. Jason could you email me your contact number? Would really like to ask you a few more questions real time. Again many thanks!

  29. We are in Canada (Ottawa) looking at installing solar panels for our 20×40 concrete pool. We are trying to decide between FAFCO Panels (the one I was shown was a solid piece with no venting) and Aquatherm panels. I have two questions:
    1. Is there any concern about FAFCO panels not being vented and there being moisture build (after a rain) or “sweating” of the panels being harsh on the roof shingles? Without the venting how do the shingles properly dry out after a big rain?
    2. What is the advantage of a 2″ vs a 1.5″ header?


    1. You are probably looking at the EcoSun brand. The “vents” in an Aquatherm EcoSun panel have nothing to do with moisture release. They are there to reduce wind uplift, and don’t do a good job of that. Their own website calls them “patented ventilation slits [to] reduce wind-load on the system.”

      We hear this negative selling tactic from competitors all of the time, but usually compared to a split tube design… “FAFCO panels will rot your roof.” It simply is not true. Asphalt shingles are made from an asphaltic material on a fiberglass substrate. Both materials are impervious to water and permanent immersion does not affect them. In the presence of sunlight, shingles can develop algae if wet. Under panels there is no sunlight, so no algae (or “mold” as claimed by competitors). Anyway, shingles under all panel types dry quite readily.

      If you look at a roof where a FAFCO system has been removed (or other full-body collectors), the shingles look far better than the surrounding area due to the protection from the elements. You have nothing to fear.

      Your second question… 2″ headers have 89% more cross-sectional area, resulting in nearly half of the restriction. This results in higher flow rates, which equals better performance. I’m In Florida. They don’t build pools anymore with anything less than 2″ plumbing now due to energy efficiency standards. Larger pipe, less horsepower required for circulation. Bigger is better, and that also includes the feed and return plumbing for your system. FAFCO only manufactures 2″ headers for its commercial grade pool heating panels.

  30. Great info, Jason. Thanks for all your hard work.

    I don’t want to install solar panels on the roof of my new central Florida home as I am told it will void the builder’s warranty. I have a 3/4 acre lot with plenty of unshaded space, so ground-mounting would work well for me. A local solar panel dealer told me that if I were to add 25% more panels than normally required, I could lay the panels flat on the ground (with slight tilt for draining), so as to avoid any conflict with the HOA. Will this really work? Can’t find any documentation on the web that would support this claim. What say you?

    Also, FSEC and SRCC has performance data and Fafco has sales info but where can I find detailed Fafco product descriptions? Fafco doesn’t publish them on their website.

    1. You will lose a substantial amount of heat to the ground, particularly when the ground is cold (i.e. when you need pool heating the most). I do not advise that you put panels on the ground, but presumably more panels will offset the losses – to what extent – that is too complicated to calculate because the effect will vary substantially throughout the year. Solar Pool Heaters have been installed on roofs for 40 years in Florida, and the fear-mongering about roof warranties is unjustified. There are so few problems, and those rare situations are typically handled via insurance claims.

      I’m not sure what detailed product information you need. FAFCO does have specification sheets. I could email one directly to you if you let me know what specific panel you are looking at.

  31. Thanks Jason for the quick response. Justified or not, the builder gets to decide what constitutes a warranty violation. I’ve read about ground-mounting in a number of places, so I’m surprised to learn that you don’t recommend it. I had planned to place the panels on a gravel bed preferably with dark stones. Is there some other material that would be better suited? A solar panel dealer is proposing this type of installation, claiming that I didn’t need to go through the expense of mounting the panels in racks.

    I’ve learned more about Fafco products in this blog than is available on the Fafco website. With Revelation no longer available, it would appear that Sunsaver is the only full-body Fafco product, so I would appreciate that spec sheet. I still don’t understand why Fafco doesn’t educate the buying public on their product offerings.

    Thanks for your help.

  32. Regardless of the type of ground cover, I would advise some kind of substrate like fiberglass sheets. There is no approved ground mount method in the manufacturer’s installation manual other than an aluminum ground rack, but if the dealer has experience doing it that way with success, then I’m not prepared to say it won’t work.

    The Sunsaver is FAFCO’s full body panel at this time. I will send you a spec sheet by email. They are not widely distributed because they are rather technical for the average person, and there are few valid comparisons that can be made versus panels from other manufacturers other than physical dimensions.

  33. I live in Palm Desert, Ca. I’m having someone come out this week from both Heliocol and FAFCO. If Sunsaver is FAFCO’s best, what can I compare it to with Heliocol? Also, I have a South facing home. Desert, South facing, am I in a good position for spending less than others?

    1. The quick and easy answer is that there is no comparison. FAFCO’s SunSaver a full body (welded tube) panel. Heliocol only makes a separated tube panel. Separated tubes are inherently less efficient when the ambient temperature is cooler or if there is wind. That applies to all separated tube panels, including FAFCO’s. Don’t be fooled by a low, low price for a separated tube design. Performance vs. cost (value) is the key to the decision. Heliocol may tout some great rating figure, but if you look closely, it will be a rating based on beautiful hot weather (exactly when pool heating is less needed).

      As for how much you spend, generally you pay for what you get. Buy quality and performance. You will be happier with fewer well-performing panels than a roof full of panels that have sub-par performance.

  34. Jason – I have Fafco panels but I like Heliocols mounting clamps. Do you know if their Gator clamps fit the Fafco headers?

    1. Bob,

      The Heliocol headers are only 1-1/2″ and all FAFCO headers are 2″. Unfortunately, that will not work. That is the advantage of the FAFCO header – it’s the same size as modern pool plumbing generally, and provides better flow rates.

  35. I mostly see information for Fafco Solar Bear heating system when I do a search for Fafco Sunsaver panels and very little on the latter. On a few sites it states that the system is for above ground or in ground pools but most of the time it is only mentioned for above ground pools. Could you share your opinion and thoughts on the use of this system for in ground pools.

    Also, is 4’x12′ the largest size Fafco Sunsaver panel available? If so, what can I expect the approximate cost to be per panel? Thanks.

    1. @ Robert:

      You’re probably finding 2’x20′ panels online. These are not the same as the type of panels sold by authorized dealers. The Sunsaver panel cannot be purchased online. It is sold as part of a complete installed system, so there is no per-panel price possible. There are too many factors involved to simplify it that way. Every system needs to be properly sized, designed, and installed based on the existing equipment at your site. The largest size is 4’x12′, and they are coupled together into a system that meets your heating needs.

      You will have to contact a dealer if you want more information on the Sunsaver panel. If that’s us in Southwest Florida, our direct sales line is (239) 217-4940 and the main office is (239) 574-1500.

  36. as

    As to the myth that Heliocol solar panels have the least amount of holes per panel drilled into roof is not true. Each panel has 4 mounts each with 2holes that = 8 total per panel ! Fafco panels require 5 to 6 holes per panel thats 25% less then heliocol I have been installing, & servicing solar pool systems since 1982. hands down the Fafco ST is the most durable panel I have ever worked with, or serviced. As far as performance it heats as well or BETTER then any panel out there ! AS far as warranty and support from the manufacturer they are the best I have ever had the pleasure of dealing with ! Feel free to contact me if you have any questions.

    1. Good point, Mike. That assumes the dealer actually puts two lags in the clamp. We have seen many with just one. The problem with that is it can twist on the roof and the single lag screw tends to pull out. We’ve been making this argument for years – Heliocol panels do not require fewer roof penetrations!

      In some higher wind zones, we do put extra straps on the FAFCO panels, which causes the number of penetrations to be similar.

  37. Jason,
    Want to thank you again for all the great info and for steering me in the correct direction! I went ahead and got the Fafco system and couldn’t be more happy!

    I ordered 10 4×10 panels for my 900 sq ft pool from my local dealer. I am running a complete Pentair system using an Easytouch 8 to take care of the Solar settings. I am using a Pentair Intelliflo 3HP pump to do the duties. My concern is my flow rate and maximizing time the water is in the panels for proper heating. In other words is there a way or how do you go about dialing in the ideal RPM for FLOW RATE to maximize heat output?

    1. Absolutely. You can get a standard flow meter, or my preference is a Flow-Vis check valve and flow meter combination. For a 10 panel system, ideal flow is 40 gallons per minute or whatever is required to close the vacuum release valve, whichever is greater. Any higher flow rate and you’re just spending money unnecessarily.

      Glad you like it! Can I ask what dealer you used or city you’re in?

  38. Just to make sure I would put the Flow-Vis inline closest to the pump output? I have a check valve there now and I can just replace that with this device.

    I’m in Northern NJ and there is only 1 dealer in my area, approx 3 hours away, All Quality Solar Systems
    PO Box 31 Stone Harbor, NJ 08247.

    Thanks again!

    PS: Feel free to contact me via email

  39. Yes, we like to put it where the check valve goes, typically right after the filter. In fact, the Flow-Vis retrofit kit is compatible with existing check valves from Jandy and Praher, and even fit into 2-way valve bodies from those manufacturers. The full Flow-Vis kit comes with the valve body (from Praher) and the Flow-Vis check valve cover.

    Flow-Vis Valve in Solar Pool Heating System

  40. Awesome, I ordered the pre-assembled kit since the check valve I have installed does not have a valve body… Some cutting and gluing but I’ll get it done and report back if necessary. Again thanks for the great information!

  41. You mention above “You’re probably finding 2’x20′ panels online. These are not the same as the type of panels sold by authorized dealers. The Sunsaver panel cannot be purchased online.” But I see many online links to a 4′ x 20′ “Solar Bear” panel. Is this the same design as the Sunsaver you are touting here? Example here (but only states 10 yr warranty): I am about to buy Fafco panels, but online info is very confusing.

    1. The Solar Bear kit is not the same as the Sunsaver offered by dealers (contractors). That is for above ground pools. You will not get the same performance.

  42. Do you know if there’s a design difference between Solar Bear and Sunsaver? According to Fafco web site the Solar Bear outputs 1,014 BTU/sq.ft., the same as the Sunsaver. Pictures look the same other than the center baffle on the Solar Bear (which I assume can be bypassed). Looks like it’s just a 20′ version of the 8, 10, 12′ Sunsavers. All have 2″ headers.

  43. @Tcat:

    I am not certain, and I’m not sure what you mean by center baffle. It was my understanding that the Solar Bear systems had 1.5″ headers, but I could be wrong. That’s probably fine for most above-ground pools.

    I would call the manufacturer to get details before going that route. I can tell you unequivocally that what you get online is apples and oranges to what a dealer will do for an in-ground pool.

  44. We are looking at putting either FAFCO or Helicol solar pool panels on our roof in Northern Calif. It is very frustrating that both companies say they are the “best in the industry”. Come on, both can’t be “the best”.
    My concern is that FAFCO doesn’t warranty the parts “metal clamps and ‘radiator hoses'”. In addition, I’ve read that the clamps need to be tightened annually and that the hoses need to be replaced and can change the color of the pool, and they can stain the roof vs. Helicol parts are covered by warranty and don’t have the maintenance issues. How much maintenance do the FAFCO parts require? Do they stain the roof? Do the hoses need to be replaced? Do the clamps and wind straps need maintenance?

    1. Because of the words you are using, I know for a fact you have been speaking to the Heliocol rep or reading their propaganda online. The “metal clamps and ‘radiator hoses’” is a tired old phrase they have used for years to scare people away from FAFCO. Look closely at the words… They say “metal” instead of Stainless Steel. When is the last time your car’s “radiator” hoses needed service? The FAFCO supplied hoses (actually called couplers) are fabric reinforced and Solar Pool Heaters work at very low pressures and temperatures relative to the capabilities of the hoses. Your pool pump is only capable of delivering about 35 pounds of pressure, and that is at ground level with no other restrictions, and most pools operate at far, far lower pressures than that (look at your filter pressure gauge). Change the color of the pool – this one always makes me laugh out loud… what a joke. There was one manufacture of rubber panels that is long gone, and their panels would deteriorate and cause discoloration or particles in the pool. That has nothing to do with FAFCO, and never did.

      Let me be clear – I am not aware of my service department EVER replacing a hose clamp that was found to have a manufacturing defect that would be a candidate for warranty replacement if covered. It does not happen. Our competitors, who service our systems occasionally, never purchase couplers from us. It is a non-issue.

      It’s true that Heliocol covers parts – the parts that they manufacture. That doesn’t mean the valves, plumbing, and other components are covered. They are not, and no manufacturer in their right mind would cover parts over which they have no control. The truth of the matter is that parts generally don’t fail. There isn’t much to go wrong with a clamp, hose, bracket, screw, and similar components. The majority of covered warranty issues for all manufacturers are related to the panels themselves, and parts are a non-issue (with the exception of Heliocol’s o-rings between panels, which we routinely service). Furthermore, parts are super cheap. Buying a system because one manufacturer covers “parts” is not a good decision (in my humble opinion).

      I can point to hundreds of customers who have heard the same mumbo jumbo for a long time, nationwide. Find a dealer with integrity and go with them.

  45. Thank you for your inpiut.
    I have another question. Helicol says their panels are more efficient per the web site and at this site: I see on that site that under catagory A: Warm climate that Heliocol has a higher BTU sq. ft./day than Fafco. However for category B: Cool Climate the Fafco SunSaver Panel is ranked higher by 0.3 units. Is that a large amount? Is the San Francisco Peninsula considered a “cool climate”?

    I talked to someone who has FAFCO panels for 23 years and they love them. My consern is they said they have replaced the panels twice in 23 years; due to freezing (it doesn’t freeze that much here). 3 sets of panels in 23 years is about 7 year life expectancy. That seems awfully short.
    Is that what I can expect?

  46. @ M Wood:

    To answer your first question, Category A is generally not the correct/useful category to consider. This category is akin to when the ambient temperature is very warm relative to the body of water. For example, when it is very hot outside and the pool is cool, this is how the panels will perform. That’s great, but that’s not when we typically need pool heating the most and when you need your panels to perform the best.

    Category B is more typical of pool heating season – the ambient temperature is lower than the pool temperature. For example, let’s say it’s 65 degrees outside and the pool is 74 degrees, and we still want to heat it up more. That is Category B.

    In other words, FAFCO panels perform best when you need it most.

    Just from a logical perspective, a separated tube panel will perform better when the ambient temperature is high because there is 360 degrees of surface area exposed to the warm air. However, as soon as the ambient temperature drops below the pool temperature, or as they become closer, the separated tube panel will actually work as a radiator and lose pool heat to the atmosphere. A full body panel does not have the same problem, or at least not to the same extent. Also, separated tube panels allow wind through, which cools the pool water, again acting like a radiator or sorts.

    Regarding your second question, a properly installed system will drain completely during freezing events, and will not be damaged. In fact, the warranty covers freeze damage when installed according to manufacturer’s instructions. Freeze damage only occurs if there is water in panels that are not properly installed, maintained, or operated.

  47. Hello,

    I am wanting to have a FAFCO solar panel system installed on my roof but the “local solar installer” can not tell me specifically what type of straps are used to hold the panels in place. I have a concrete tile roof. Home was built in 2006 in Dixon, CA.

    I need to know that the straps and how they are installed will ensure there is no chance of rain penetration. Are the roof penetrations sealed? If so with what? Does it need to be resealed every so often? Do you have to penetrate the roof or are you allowed to anchor to the roof tiles? Pictures would be great.

    I think the sales guy has not gone on enough installations to clearly walk me through how it is done. I have to be certain that I am not going to Swiss cheese my roof in order to have a bit warmer pool water.

    1. Unfortunately, things are very, very different in California. In Florida we have different building codes, and the wind load requirements are unique. Here is what I can tell you. FAFCO systems use Dacron straps with 1,600 pound tensile strength. They are attached to the roof (usually) using a proprietary cap and base system. On tile roofs, an aluminum rack and substrate system is most typically used, but again, that depends on your local requirements and roofing materials. How the attachments are done and sealed is also up to local codes and methods. As for sealant, all contractors have their preference. We use Geocell 2300, which we have found to be extremely reliable. Resealing is not anticipated – sealing penetrations (if required) is a permanent thing – at least permanent until it is time for a new roof.

      So in short, you will need to get straight answers from your dealer. If the salesperson does not know, ask to talk to a technician or the owner. One thing is for certain – a solar dealer does not stay in business by turning your roof into Swiss cheese. Ask how many installations they have done. The answer is probably well into the thousands. Roof leaks are extremely rare when installations are done right, and a company that has been doing it a long time is usually a safe bet.

  48. I am in the process of having a pool built. I’ve come across an issue with the pool builder threatening to void my pump warranty if I have a solar pool heater installed. This pool builder uses a 2-speed 2.5hp pump (Jandy). Their concern is the solar will burn up the pump when it goes to low speed. The salesman (who installs FAFCO solar panels) says that 1hp is more than enough to run the 6 panels I would need on the roof plus the operation of the pool. The pool company is also concerned with the gpm required to run the panels (6 panels, 4 are 10ft and 2 are 12 ft) while at the same time having enough pump power and gpm to run the waterfall feature and the Polaris. My pool is 16’8″ x 32′. Can you comment on how the solar will operate with a 2 speed pump and if it will work when the pump is on low speed (probably around .75hp). Where can I find specifications on what is needed to run the panels? Thanks for your help. If you need more information or have other questions, feel free to email me.

    1. Andy,

      First off – ditch the 2-speed pump and get yourself a variable speed pump. This will give you maximum flexibility with pump speeds for all of your features. Whether you use the two-speed pump recommended by your pool builder, or a variable speed pump as I am recommending, the pump would never run at low speed when the solar is on when a proper automation system. When the sensors call for solar heating, the pump should change speed, or in the case of a 2-speed pump, change to high speed. You should be looking for total flow of 24 gallons per minute for efficient solar operation, but anything above 18 would be fine. That’s a very low flow rate, and typically a 1 HP pump would be more than enough on a single story roof. However, pressure-side cleaning systems can add a lot of back-pressure, so you have to watch out for that. The best solution is to run the pressure-side cleaner only when solar is off.

      I find the claim by your pool builder a bit funny, because at low speed the pressure will be LOWER, not higher, and the likelihood of burning up your pump would DECREASE, not increase at a lower speed.

      As for threatening to void your pump warranty – balderdash. The pump manufacturer provides your warranty, not your pool builder. He may refuse to service it if something goes wrong, but he can’t void the manufacturer’s warranty, and you won’t either by installing solar panels.

      By the way, I’m glad you found me, but my new blog is at This site is no longer updated.

  49. Hi Jason,

    Quick question, I had a company come out to my house and quote me for the Fafco solar panels, and then my pool cleaning company said they would give me a quote as well, they quoted me Techno-Solis panels? Cost difference is fafco is only $500 more. Im in northern California if that makes any difference? But which one do you prefer, I cant find much online for the Techno-solis one?

    Thank you for your time!


    1. The Techno-solis is a way distant fourth place in Southwest Florida, the best market in the nation for solar pool heating. That should tell you something. $500 is nothing over the life of the system. We are often $1,000 over the third best panel in this market. You get what you pay for.

      That said, there is more to the system than just the panels. You need to be aware of valves, controls, and other components. The dealer themselves is a key consideration. Workmanship is important!

  50. Can you comment on color panels such as provided by Heliocol. I believe no other company is installing panels other than black. Thank you for any response.

    1. Sure – I have never seen a panel other than black installed in Southwest Florida, and for good reason. Black absorbs more heat. The colored panels look fancy, but perform very poorly relative to black panels. From what I can tell, it’s just a marketing ploy. Again, I have never seen them installed here. It just doesn’t make sense.

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