SOLAR HEATING YOUR SWIMMING POOL OR SPA

A solar pool heating system consists of a solar pool collector, automatic control, diverter valve, and associated piping. These components typically work with the pool's existing pump, filter, and heater.

Typically, we use an open loop, drainback design. Pool water is circulated directly through the collectors when the pool's standard circulation pump is activated. When the pump turns off, the water in the collectors drains back into the pool.

To automate the process, a differential controller compares the water temperatures measured at the solar collector and the pool. If the collector temperature is at least 4°F higher than the pool water and the pool is below the desired set point temperature, the control opens the diverter valve.

This allows circulation of pool water to the collector and back if the pump is on. A diverter valve in the system either sends the water through the solar collector or straight back to the pool from the pump.

Not only does this design employ all existing equipment, it enables the direct transfer of collected heat to your pool. And when your existing heater is needed, the preheated incoming water boosts the heater's efficiency (wastes less fuel).

Because equipment costs are low and efficiency gains are high, these systems can pay for themselves very quickly, often five years or less.

Collectors for pool heating are much simpler than those used for solar domestic hot water. Most solar pool collectors use an unglazed, plastic, flat plate collector, with no insulated box. The absorber plate is the black surface of the collector, which, like any dark surface in the sun, converts solar radiant energy into heat. The liquid to be heated passes through the risers, which are parallel tubes integrated into the absorber plate. The risers are connected at each end by manifolds, which serve as the collector's inlet and outlet pipes.