Swimming Pool Blog
Swimming Pool Blog
Solar Pool Heating Systems
Solar Pool heating can easily add months to your swimming season. Solar heating works by collecting free energy from the sun and transferring it to your pool, solar pool heaters allow you to open your pool earlier, and keep your pool open long after your neighbors have closed theirs up for the season.
With a Solar Pool Heating System, you’ll get the satisfaction of knowing that you’re heating your pool with the most cost-effective, cleanest, most environmentally friendly source of energy there is…the sun!
Installing a Solar Pool heating System Will significantly reduce swimming pool heating costs. They’re cost competitive with both gas and heat pump pool heaters, and they have very low annual operating costs. Actually, solar pool heating is the most cost-effective use of solar energy in many climates.
Most Solar Pool Heating Systems require the following:
Solar Collector - the device through which pool water is circulated to be heated by the sun.
Filter – removes debris before water is pumped through the collector.
Pump – circulates water through the filter and collector and backs to the pool.
A Flow Control Valve – Automatic or manual device that diverts pool water through the solar collector. Pool water is pumped through the filter and then through the solar collector(s), where it is heated before it is returned to the pool. In hot climates, the collector(s) can also be used to cool the pool during peak summer months by circulating the water through the collector(s) at night.
Some systems include sensors and an automatic or manual valve to divert water through the collector(s) when the collector temperature is sufficiently greater than the pool temperature. When the collector temperature is similar to the pool temperature, filtered water simply bypasses the collector(s) and is returned to the pool.
Solar pool collectors are made out of different materials. The type you’ll need depends on your climate and how you intend to use the collector. If you’ll only be using your pool when temperatures are above freezing, then you’ll probably only need an unglazed collector system. Unglazed collectors don’t include a glass covering (glazing). They are generally made of heavy-duty rubber or plastic treated with an ultraviolet (UV) light inhibitor to extend the life of the panels. Because of their inexpensive parts and simple design, unglazed collectors are usually less expensive than glazed collectors. These unglazed systems can even work for indoor pools in cold climates if the system is designed to drain back to the pool when not in use. Even if you have to shut the system down during cold weather, unglazed collectors may be more cost effective than installing a more expensive glazed collector system.
Glazed collector systems are generally made of copper tubing on an aluminum plate with an iron-tempered glass covering, which increases their cost. In colder weather, glazed collector systems—with heat exchangers and transfer fluids—capture solar heat more efficiently than unglazed systems. Thus, they can be used year-round in many climates. Glazed collectors also can be used to heat domestic hot water year-round.
Both glazed and unglazed collector systems should include freeze protection if they’ll be used in colder conditions.
EVALUATING YOUR SITE’S SOLAR RESOURCE
Before installing a Solar Pool Heating System, you first need to consider your site’s solar resource. The efficiency and design of a solar pool heater depends on how much of the sun’s energy reaches your building site.
Solar pool heating systems use both direct and diffuse solar radiation. Therefore, even if you don’t live in a climate that’s warm and sunny most of the time – like the southwestern United States- your site still might have an adequate solar resource. Basically, if your building site has un-shaded areas and generally faces south, it’s a good candidate for a solar pool heating system. Your local solar system supplier or installer can perform a solar site analysis.
Solar system contractors use worksheets and computer programs to help determine system requirements and collector sizing.
Basically, the surface area of your solar collector should equal 50%–100% of the surface area of your pool. In cooler and cloudier areas, you may need to increase the ratio between the collector area and the pool surface area. Adding collector square footage also lengthens the swimming season.
For example in northern California, most people use outdoor pools 6–8 months per year, so they typically size their systems at 60%–70% of the pool’s surface area.
In any climate, you can usually decrease the required collector area by using a pool cover.
You’ll also want a properly sized pool pump for a solar system. If you’re replacing a conventional pool heating system with a solar system, you may need a pump larger than your current one or a separate, smaller pump to move the pool’s water to and through the collectors. Collectors can be mounted on roofs or anywhere near the swimming pool that provides the proper exposure, orientation, and tilt toward the sun. Both the orientation and tilt of the collector will affect your solar pool heating system’s performance. Your contractor should consider them while evaluating your site’s solar resource and sizing your system.
Solar pool heater collectors should be oriented geographically to maximize the amount of daily and seasonal solar energy that they receive. In general, the optimum orientation for a solar collector in the northern hemisphere is true south. However, recent studies have shown that, depending on your location and collector tilt, your collector can face up to 45º east or west of true south without significantly decreasing its performance. You’ll also want to consider factors such as roof orientation (if you plan to mount the collector on your roof), local landscape features that shade the collector daily or seasonally, and local weather conditions (foggy mornings or cloudy afternoons), as these factors may affect your collector’s optimal orientation.
You can usually mount collectors flat on your roof, which might not be at the optimum angle but more aesthetically pleasing. You will, however, want to take roof angle into account when sizing your system.
INSTALLATION AND MAINTENANCE
The proper installation of a solar pool heating system depends on many factors. These factors include solar resource, climate, local building code requirements, and safety issues. Therefore, it’s best to have a qualified solar thermal systems contractor install your system.
A solar pool heater is clean, easy, cost effective, and gives your family and friends more swimming fun every year.