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Solar Pool Heating – How it Works

It Makes Your Cold Pool Warm!

SolarCraft’s solar pool heating systems work seamlessly with your pool equipment and are fully automated. You set the desired water temperature on the solar control, and when solar energy is available at the solar collectors, an automatic motorized valve diverts the water through the solar collectors and carries the suns heat back to the pool. This process is continued until either the pool’s filter pump shuts off for the day or the desired pool temperature has been reached.

solar pool heating how it works illustrationIn most cases the existing filter pump can easily provide adequate flow to the solar panels. The only requirement is that the filter pump needs to be operated during the day, (10:00 AM to 5:00 PM). This is the time most pool professionals would recommend your filter be operated regardless of whether you have solar or not. It is also the time the pool is most likely to be used, and the time when good circulation for distribution of sanitizing chemicals is required.

How Pool Water Gets Heated From the Sun

  1. Set your desired water temperature and a sensor determines when the system turns on and starts heating water
  2. Your pool pump sends cold water from the pool through a series of channels in the solar collectors
  3. FAFCO’s polymer solar collectors use the sun’s energy to heat to your cool pool water as it moves through the panels, returning the water to the pool with a significant temperature gain
  4. Luxuriously warm, solar heated water flows back into your pool until it’s heated to the desired temperature

Our Solar Panels

solar pool heating panel

FAFCO Revolution
Pool Heating Solar Panel

The quality of SolarCraft systems starts with a FAFCO solar panel with unmatched ability to transfer about 85% – 90% of the sun’s energy into the pool. The FAFCO Revolution solar panel was tested by FSEC to put out 1063 BTUs per sq ft, per day (the industry’s highest).

Types of Systems

Solar pool heating systems come in many sizes and styles. Over the years all manner of different configurations and materials have been tried in transferring the sun’s energy into a swimming pool. In the early to mid 70′s copper collectors were used. They proved to not only be costly but, because of the nature of a swimming pool’s chemistry they corroded quickly and the copper oxide deposits then stained the pool.

FAFCO logoIn 1969 FAFCO introduced the modern polymer solar collector. This technology was a quantum leap in terms of heat production, durability, weight, and esthetic appeal. The patented material used in FAFCO panels is not affected by exposure to pool chemicals. FAFCO Panels have 240 very small tubes side by side, with no space between. Every square inch of the solar panel has water running through it for greatly increased efficiency.

Systems have also been developed using EPDM rubber, but due to oxidation from the ultraviolet wavelength of the sun’s energy and effects internally from chlorine and freezing, they are not as common as the plastic family of pool panels in widespread use today.

Panel Orientation

The number one rule is to not design or install a solar pool heating system that faces in any portion of the 180 degree arc of the compass that faces north. When you need it the most it won’t work. Installing solar panels in the shade of a tree or building will also not be functional.

For pool heating panels any mounting area within a 45° arc from due south is acceptable. After that additional panels should be used to increase the collector area as performance decreases due to the orientation away from south.

Control Systems

Manual Systems

A solar pool heating system can be operated by simply using a 3-way valve. The system is either on or off. Although this simple method is bullet proof, in other words…no service, it has severe drawbacks, the first problem is performance. If there is flow through the panels in cold, rainy or otherwise inclement weather not only is the system not producing any heat, it can actually cool the pool. The net result may be a pool that is actually colder than the one next door due excessive heat loss.

The next dilemma is heat control. During many months the system produces more daily heat input to the pool than is actually needed and this may result in a pool that is too warm. Although this may seem to a cold pool owner as a not so terrible problem, diving into a 95° pool may not be desirable either.

Automatic Systems Offered by SolarCraft

The use of an automatic control system fully automates the solar heating system by using a microprocessor based differential control, sensors on the roof and in the pool water, and a motorized valve to direct the flow of the water.

When the control detects via a sensor on the roof that the panels are 5-10° warmer than the pool, then the control activates the motorized valve, turning to the “Solar On” position.

Once the desired temperature is reached or the panel temperature falls below the pool temperature then the solar system is turned off, rotating the valve to the “Solar Off” position. All of the solar pool heating systems that SolarCraft installs include an automatic control system.