We all know how hot the water in the garden hose gets when left out in the sun, especially on a black driveway. Imagine fanning the entire flow of your pool pump out over your sun baked driveway, watching it run down, collecting it again at the other end and sending it back to the pool! What effect do you think this will have on the pool temperature after time? Solar pool heating succeeds in harnessing that power in a controlled fashion by diverting your cool pool water through a series of channels in the collector plates and returning the water to the pool with a significant temperature gain. The amount of that gain will vary due to a multitude of factors, which should be taken into consideration when designing a solar collector system. I have seen as much as a 20-degree instantaneous rise and as little as a 3-4 degree rise with sun on the collectors.
As the water is heated on an hourly and daily basis, the temperature of the pool begins to rise and you will achieve a daily average temperature increase of 10-15 degrees F. with a properly sized solar collector array.
Solar heating for pools remains relatively inexpensive compared to other means of pool heating because three of the main components of the system are already in place.
The heat storage tank is your pool, the mechanical movement of the water through the collectors is achieved with your existing filter pump, and the collector array mounting rack or surface is typically an existing roof. This means that the minimum installed components need only be a proper sized solar collector array, piping, and valving to make it work. We will always recommend an electronic controller with sensors to assure you are achieving peak efficiency from your installed system, but the solar collector will work surprisingly well without one.
Sizing of the solar collector system:
Size DOES matter. Collector size and flow rate are the 2 most important considerations when designing a collector system for pools. Because almost all heat is lost through the top surface of the pool we use the physical dimensions of the pool surface area as a benchmark for size. Did you know that heating a pool is like trying to heat a house with no roof on it and that it takes more than 3 times the amount of heat to warm a pool as it does to warm your house!
In our area of the country, the Mid-Atlantic region, we can only expect about 5 months of use out of our pool unless enclosed indoors. A factor of .67% of the pool surface area is a good place to start for sizing. We have done systems with as little as .50% and as much as 100% of the pool surface area, but for general estimates plan on 55-75% of the pool surface. See our estimating page for info.
Example: 16x32 in ground pool 16 x 32 = 512 sq feet
Factor of .67
512 x .67 = 343 sq feet
This pool would need in the neighborhood of 343 sq feet of collector to be
Considered truly heated. (10 to 15 degree rise resulting in 80-90 degree water over 5 months of use)
There are many other factors to consider when determining size such as degree of orientation of the collector surface relative to true south, roof pitch, shading on the pool and use of a heat retention blanket when the nights will be below 60 degrees. There is no substitute for actual field experience when it comes to determining size, and although homeowners can get a pretty good idea of the size they may need, a certified solar contractor will be able to determine exactly what is needed. We pride ourselves in sizing and installing solar pool heaters that work! With such an investment there should be no question as to whether or not it will provide an adequate source of heat to the pool. Our customer’s satisfaction is our best measure of proper sizing, and we have not installed a system that failed to provide 100% satisfaction.
Remember, with the proper flow of water flowing through the proper sized collector system during the proper hours of the day, your pool will be heated!
Beware of unscrupulous store salesmen or solar contractors who tell you that you can heat a 20 x 40 in ground pool with 4 solar panels. It simply will not work. And yet, we have witnessed this type of sale to a customer simply to make a sale and with no regard for the performance, average temperature increase, or customer satisfaction. We have even seen contractors install miniscule systems on the north face of a house roof with the assuring comment that it “should work in June or July”. The fact is that June and July are the periods when you should not need to rely on your solar heater so much as you will in May, August and September. We take pride in our services, our products and our expertise in proper design of a solar pool heating system. We design a system to give either a 10 or 15 degree average temperature rise, that will give you 80 and above from mid May until the first week in October, and that will function flawlessly from day one. We will transform your cold unused pool into a warm, well used centerpiece of your home and family life, an oasis that will offer you pride of ownership rather than resentment of your chilly, unusable pool. We design for average temperature ranges between 82-88 degrees in your pool. Our solar pool heating systems work. We guarantee it.
The absolute best place for locating your solar collector is on a south-facing roof.
We prefer a roof because it is up and out of the way, most houses have at least one roof surface facing south. Using an existing roof reduces installation time and cost because the roof is one of the largest unused expanses of real estate on a residential lot. Of course we have used barns, garages, and lean-to’s as well as pergolas, hillsides, cabanas, sheds and virtually any area of sunny open yard. These are all areas of consideration for the collector-mounting surface. We look first for the largest expanse of roof with a south, southwest, southeast, west, or east exposure in exactly that order. Get out your compass and remember that true south is actually 12 degrees west of magnetic south in most of New Jersey. If there is no feasible roof available, then we can consider constructing a wooden mounting rack, but this will add somewhat to the initial expense. We have also pioneered a system of excavating and shaping of the earth and attachment of the solar collectors directly to the ground. This works very well in areas where there are large building lots. When done this way, the panels can be insulated on the underside to prevent the heat from conducting into the earth. We have had excellent success with this type of installation and our flair for placement and design is without equal. The only constant that remains throughout all locations is our ability to place the collectors in a full sun area for optimum performance.
A word about Controls:
All that is needed for controlling the flow of water to the solar collector is a good quality, non-positive 3-way valve. We use Hayward and Floverter valves as they have set the industry standard for quality and durability. All of the solar systems we install employ an automatic control. We offer the 10 year Heliomatic HM-4000 combo as our bulletproof standard control as well as the state of the art Aqua Solar from Goldline Controls. This fully automatic digital solar control panel will allow you to set and maintain a desired temperature. Using a combination of sensors, the unit will determine if there is a presence of sun or heat at the collectors, what the water temperature of the pool is, and if there is a demand for heat and a presence of sun or heat, the automatic actuator will open the solar control valve and allow the water to flow through the collector until the desired temperature is achieved. All this so that you can basically set it and forget it! The Aqua Solar will help you to achieve maximum efficiency for your collector and in many cases it will increase performance 10-15%. We find that the installation of the Aqua Solar exceeds the performance gain of installing an extra solar panel! All readouts are done on a digital LCD inside the control box. The default temperature reading is pool temperature, eliminating the need for an underwater thermometer. You have the option of cycling through temperature at the solar collectors (on the roof, often 135 degrees!) the temperature of the pool water, the temperature of the water returning from the solar collector (great for seeing your instantaneous gain) and the option of sensing ambient or outside air temperature. There are other controllers on the market, but the Aqua Solar is the most advanced, user friendly and user programmable controller available. An automatic control will take the mystery out of operating your solar heating system and will contribute to the overall efficiency, quality, and enjoy ability of your professional solar pool heating system installation.
For those of you employing some sort of automation for your pool, such as the Jandy Aqua Link, the Goldline PS series as well as Compool, will be pleased to know that virtually all of these controls have built in solar control capability. We can simply tie into your existing automation and give you seamless capability to monitor, adjust and control your solar heating system with all the convenience that your existing system allows.
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