Solar Southwest Florida

Fafco Solar Video on Pentair Variable Speed Pump

Fafco Solar just released a short promotional video on the Pentair Variable Speed pool pump.

The variable speed pump is a perfect match for solar pool heating systems, especially when an automatic controller is used. Without a controller the pump can be scheduled to run at optimum solar circulation speed when solar energy is most likely to be available. Adding a controller adds the capability of changing the pump speed based on the availability and demand for solar heating.

With or without solar energy, the variable speed pump will pay for itself with energy savings. You can cut pumping costs up to 90% with this great technology while getting a far quieter and longer lasting pool pump.

Solar pool heaters work better with variable speed pumps because the optimum flow rate can be achieved to maximize solar performance. A single speed pump is typically fine to use with solar pool heating, but if you want maximum pool heating, a variable speed pump can both save you a tremendous amount of money and provide the proper flow rate.

Typical efficiency vs. flow curve for solar pool heating panels (FAFCO Sunsaver shown).

Most solar pool heating panel manufacturers recommend a flow rate of 4 gallons per minute per panel. If you have seven panels, you need a flow rate of 28 gallons per minute. Anything less and the efficiency drops off quite rapidly. Anything more and you are wasting money on  your pumping costs, pumping water at a rate higher than required for solar pool heating to be efficient.

When we have a solar pool heater installed, we insist that every job gets a flow meter installed (at least temporarily).  The pump can be programmed to operate at the proper speed when solar pool heating is likely to be required. With an automatic controller, the pump can be set to go to optimum speed whenever solar pool heating is required, but reduce the speed when heating is not active.

There are lots of other variable speed pump resources on my Solar Southwest Florida blog. I have also assembled some Pentair variable speed pump marketing videos below. Enjoy!

As inefficient electric pool heat pumps and gas pool heaters are, they have their place in heating Southwest Florida pools. It’s no problem to have both solar pool heat and a heat pump or auxiliary gas heater. In fact, the whole system can be automated with fairly simple controls and automatic valves.

A system of valves and actuators control solar pool heat and a heat pump for a pool/spa combination.

Many thousands of heat pumps are installed in Florida, the result of aggressive advertising campaigns and irresponsible claims by manufacturers about how efficient heat pumps are. The fact of the matter is that heat pumps cost an arm-and-a-leg to operate. Heat pumps are important when the desired temperature is critical to attain and maintain at all times. For example, hotels, condos, and individuals with medical hydrotherapy needs often require a constant and elevated pool temperature. In these cases, the holy grail is a solar pool heater in conjunction with a heat pump.

Because gas prices are relatively high in Florida, the only reasonable application for a gas heater is in situations where raising the pool temperature quickly is required or where swimming is anticipated during cold ambient temperatures. Long-term constant heating with gas heaters is outrageously expensive.

If you choose to have a heat pump or gas heater, or you already have one installed, integrating solar pool heat is easy. An automatic controller can set the solar pool heater as the primary heat source and revert to auxiliary heating. In most cases, a solar pool heater is installed, and the auxiliary heater is only operated on-demand by the homeowner manually switching on the heater. This can be as easy as pushing a button on a controller or even using a remote control to switch on the auxiliary heater.

SunTouch Controller

The AquaLink RS, Aqua Logic, and other high-end pool controllers are very capable at controlling multiple heat sources. If you already have a pool automation system, it is likely that solar pool heat and a heat pump can already be controlled from it. If not, I have been recommending the affordable Pentair SunTouch with the optional Quicktouch II Remote. Once programmed, operating the pool equipment is as simple as pressing buttons on a remote. It can work with any combination of heat sources and can even control your spa and a variable speed pump. In some cases, pool lighting and landscape lighting control can also be integrated.

Fafco Solar installed a solar pool heat system this week at a home that already had a heat pump. Adding a SunTouch controller allowed the homeowner to optimize the operation of their solar pool heater, while providing the option of supplemental heat at the press of a button if desired. This time of year, solar pool heating alone typically gets a covered pool to around 85 degrees. The grandkids were coming in town this week, and he wanted the pool to be 88 degrees. The controller allows the pool to be heated by solar if possible, then switches on the heat pump to get the last couple of degrees needed at a reasonable operating cost.

Every day our solar advisors are in homes comparing FAFCO solar pool heating panels to Heliocol. Both brands have been around a very long time (FAFCO invented the polymer solar pool heating collector). Let me make this simple – FAFCO is the quality, value, and performance leader. Heliocol is sometimes the low cost leader. That about sums it up.

But you probably expect a bit more information, so I’ll break down the numbers.

In SW Florida, the most popular Heliocol panel is the 4′x10′ HC-38 solar collector. All manufacturers list a nominal size for their panels, and the closest FAFCO panel is also a 4′x10′ collector, however, FAFCO has three different brand options in this size: the Revolution, Sunsaver, and Sunsaver ST (split tube).

The Fafco Revolution is the top-of-the-line solar panel on the market, and beats all competitors when it comes to the most important metric, BTU output. The Revolution’s 1,064 BTU per square foot, as rated by the Florida Solar Energy Center (FSEC), leads the industry. That’s easy information to find on FSEC’s website. On a cost and performance basis, the closest FAFCO option to the HC-38 is the Sunsaver ST. FAFCO’s lowest performance option still wins the performance battle!

Fafco vs Heliocol Comparison (Click for larger Image)

There are little games played in the industry to try to make manufacturers’ panels sound better performing, or at least equal. Here are the facts:

• A FAFCO Sunsaver ST has a larger surface area than the Heliocol panel of the same nominal size (4′x10′).
• If you are comparing the same number of panels, regardless of type, a FAFCO system will have a higher BTU rating at the FSEC 95°F rating, which is the most appropriate rating based on typical operating temperatures of solar pool heating panels.
• Heliocol has a smaller header pipe (1-1/2″ inside pipe size). They list a 2″ manifold on their specification sheet, but this is the outside diameter, which is irrelevant to the performance.
• All FAFCO Revolution, Sunsaver, and Sunsaver ST panels have 2″ inside pipe diameters. Because the outside diameter is irrelevant, FAFCO does not list the size, but it measures 2-3/8″ if you are interested. Note that 2″ inside diameter means 78% more water volume!
• FAFCO panels employ a subheader that balances flow through the collector system, ensuring that the system fills up completely with water and the entire surface area is “wetted.” Heliocol collectors have tubes connected directly to the header, and no way to balance the flow through a collector system. As a result, some collectors may not fill completely with water, and may provide no heating capacity. This is especially true on larger or multi-bank systems.
• The FAFCO subheader does result in additional pressure loss and back pressure on the pump, but this is more than compensated by the 2″ plumbing throughout the collector loop. The Heliocol system uses 1-1/2″ PVC pipe throughout the system, including fittings, isolation valves, check valves, and diverters. A typical Heliocol system results in more back pressure on the pump than a FAFCO system, but they want you to think that the panels are all that counts.

I’ve heard just about every myth out there about FAFCO panels. If you hear something that doesn’t sound right, it probably isn’t. Let me know and I’ll give you the real scoop.

The bottom line is that FAFCO panels are the highest rated in the industry by independent and trusted authorities, the results are published and readily available, and even FAFCO’s lowest rated panel beats the competition.

The best way to control a solar pool heat system is with an automatic controller. If you do not have one, you are missing out on great convenience, and not maximizing your solar pool heating investment. Most people who do not have a controller just leave their solar pool heating system all the time. That means any time the pump is running, water is flowing through the solar panels.

Unfortunately, solar panels can also act like a radiator, giving pool heat back to the atmosphere. On very cloudy days or during rain, you may actually be cooling your pool if you solar pool heater is running. Usually this is not a huge problem, but it is definitely less than optimal.

One thing you can do is set your pump timer with ideal times to run the pump when you are most likely to get good performance from your solar panels. If your panels are mounted on the south roof, 10:00 am – 2:00 pm are the prime hours, and you pump should be run during this time. If your panels are mounted on the east roof, you will want to start you pump a bit earlier, and definitely don’t run it too late. The biggest mistake I see is when panels are mounted on a southwest or west roof, and the homeowner has the pump set to start at 8:00 am. On a cool morning with no sun hitting the panels, some cooling is highly likely. I recommend no earlier than 10:00 am for a pump start time, but the stop time depends on the time of year.

The best thing to do is observe your panels and make sure you pump is running when the sun is hitting them. Shading and time of day are important to evaluate.

Again, an automatic controller is your best option for controlling your solar pool heat, but if you aren’t willing to make that investment, take some simple steps to maximize your system’s performance!

FAFCO Collector Layout Strategies

It has long been the basis of solar pool heat design to have an opposite end feed and return. In fact, it’s published in several books and manuals about solar pool heating. This is not the case with FAFCO solar pool heating panels, which can be installed with same side feed and return!

Opposite end feed and return simply means that the plumbing that brings up to the solar panels and connects to the lower header is connected at the opposite end of the bank of solar panels from where the plumbing connects to the return line to the pool. Conceptually, this is done to ensure that all solar panels get filled with water and the flow rate is even throughout the bank of panels.

The FAFCO system is a bit different, mainly because FAFCO’s panels have a 2 inch header, 78% more volume than the competition’s 1-1/2″ header, and a subheader that helps to balance the flow among all panels in a solar array/bank. This ensures that all panels have the same flow rate.

It is important to note that you cannot exceed 12 panels in a row with same side feed and return (see Figure 4). Also, split feed and multi-bank systems with varying heights must use opposite end feed and return lines (see Figure 5). The FAFCO manual is very clear about the layouts that are permitted.

Same Side Feed Return Example for Solar Pool Heat Plumbing

SunTouch Controller Installation

I finally got around to installing my Pentair SunTouch Solar Controller at my Fort Myers home. I don’t have solar pool heat (yet), so I have been procrastinating. Why install a SunTouch without a solar pool heating system? Because it does so much more than just control a solar valve!

The SunTouch is made to work with an actuator to automatically turn solar pool heating on and off based on the desired temperature and the available heat on the roof.

Here are several great reasons to install a SunTouch Controller:

• It’s a great compliment to my Pentair Variable Speed Pump (VS-3050). The SunTouch takes over the control of the pump functions and speeds, allowing you to program various speeds for things like water features, automatic cleaners, solar, and auxiliary heaters.
• It will control a heat pump or gas heater with or without solar pool heat. I happen to have a heat pump (I know, not good, but it came with the house).
• I can control my landscape lighting (LED, of course) with one of the auxiliary relays and put the transformer on a timer.
• I can control the pool lights and program run times.
• With the QuickTouch remote, I can activate features from the handy remote control. While I have the landscape lighting and pool lights on programmed schedules, I can manually turn them on from the remote. I can also manually force the pump on at various speeds.

QuickTouch Remote and Receiver

Because my pool and landscape lighting were on the same circuit, and because I still have old energy-hog incandescent pool lights (2 x 300W), I am excited to be able to run the landscape lighting independently now. For added security, and because they use virtually no energy, I set my landscape lights to run all night – something I wasn’t able to afford with the pool lights. One day I’ll spring for the LED pool light upgrade.

I set out to do this project yesterday and it took a little longer than expected with all of the auxiliary features I wanted to control. I also had to rewire the lighting transformers because the pool and landscape lighting were on the same circuit. I went ahead and installed the water and solar sensors so I’ll be ready to go when I add solar pool heat this spring. Finally, I took the opportunity to wire a GFCI outlet next to the SunTouch for extra convenience when running my electric trimmer.

The initial programming of the SunTouch is a bit complex, but fortunately my experience at Fafco Solar had me prepared for this challenge. The menu operation is not very intuitive, but once you understand it the button functions, it all makes sense. The SunTouch documentation on the variable speed pump programming is a bit confusing, but once you read the pump manual itself, it all comes together. I was able to easily configure my remote control to control my pump and lights. The QuickTouch remote connection is also

I didn’t connect the heat pump relay, partly because I ran out of time, but after thinking about it I would rather not have it on a controller. I want to feel the pain every time I manually turn it on, and remember how much that thing costs to run! I can see the benefit of connecting it for people who have pool/spa combinations to fully automate spa heating.

Overall, I am very impressed with the system, and I look forward to installing my solar pool heating system soon!

My Pool Equipment with SunTouch Solar Controller Installed

When you’ve got it all, things can get pretty complicated. Solar pool heat plumbing with a heat pump and a spa can result in a spaghetti factory of plumbing at your pool equipment. Pictured below is an Estero, FL system containing:

• Solar Pool Heat
• Auxiliary Electric Heat Pump
• Pool and Spa with Blower Combination
• Cartridge Filter
• Pool Drain Valve
• Aqualink automatic controller
• Landscape lighting

Complex Solar Pool Heat Plumbing

The good news is that the automatic controller does just about everything you can expect to control the pool and spa heating automatically. The only user intervention required is to set desired temperatures and priorities for heating sources. The owner may also want to manually adjust the spill-over waterfall from the spa to the pool.

Note: Fafco Solar added the solar pool heat to the existing system installed by others and connected the solar pool heat to the Aqualink controller.

What does the Acronym SPH stand for?

SPH = Solar Pool Heat

a.k.a Solar Pool Heat

SPH is an acronym for Solar Pool Heat or Solar Pool Heating systems. SPH systems use polymer solar panels to heat pool water. SPH systems use solar thermal technology and do not produce electricity. Solar Pool Heating systems circulate pool water through the solar panels to transfer solar radiation to the pool, increasing water temperatures.

SPH Panels - Solar Pool Heating System

If you have a solar pool heating system, your dealer may mention the manifold. This is just a set of valves that control the flow of water in your solar pool heating system. The function of the solar pool heat manifold is to turn you solar on or off by bypassing the solar panels when necessary. Your manifold may or may not include isolation valves to isolate the solar panels in the event that the system must be serviced.

Let’s take a look at an example manifold. The one pictured below includes two high quality Jandy brand isolation valves, a Jandy brand bypass valve, and a motorized actuator that is controlled by a pool automation system, in this case, an Aqualink system. Note that the bypass valve is also known as a diverter valve, a 3-way valve, or generically as a Jandy valve, which can be confusing.

Solar Pool Heat Manifold (Click for Larger Image)

Your solar pool heat manifold may look significantly different from this, but the concept is the same. We need to be able to control whether the water from the pool pump goes up to the solar panels, or bypasses the solar panels and returns directly to the pool. In the current configuration, the solar pool heating system is on, and water is able to flow through the panels on the roof. The red “X” is the bypass plumbing. When the bypass valve is in the other position, the solar panels are bypassed, and the water flows directly back to the pool.

The isolation valves should NEVER be closed when the bypass valve is in the solar-on position. This “dead-heads” the pump, meaning that the pump is running, but there is nowhere for the water to go.

It should be noted that the bypass valve is typically a “non-positive” valve. That means that it does not actually stop all of the water from going one way or the other. This is important so the water in the panels can drain back into the pool when the solar pool heating system is off. Draining water from the panels helps prevent freeze damage to the panels. This can be accomplished several ways, which are beyond the scope of this article, but note that it may not be readily apparent how your valve is made to be non-positive. Some systems, due to plumbing configurations, are manually draining. They must be drained manually or using a drain valve if installed.

Some common parts of the pool heating system plumbing are not shown here, like check valves that only allow water to flow in one direction. I’ll get to that concept in another article!

There are several ways to make a solar pool heat manifold, and some features may not be present in yours. If you have a question about your manifold, take a picture and email it to me at jason (at) facosolar.com and I can help you make sense of it!

It was in the 60′s last night, and my pool has already started to lose degrees. Cool nights wreak havoc on uncovered pool temperatures. Pulling your cover out of storage will help, of course.

Most people wait until too late in the season to make the decision to buy a solar pool heater. This time of year the phone starts ringing off the hook, and inevitably we get a bit backed up. It’s just part of the business. People lose out on some of the best swimming weather – in the early fall when outside daytime temperatures are delightful, but pools are cool!

If you want a solar pool heater, NOW is the time to act to take advantage of what I call the best time of the year in Southwest Florida.

For those of you that already have solar pool heating, NOW it also the time to give it a test to make sure it is working properly and to remember how to work your controls (manual or automated). If you need service, get on the schedule before the snowbirds come back! If you need some tips, let me know, or call your dealer.