Open loop system or closed solar pool water heaters

An open loop solar pool system heats the water directly from your pool being added to the current loop system. During normal pool operation the water will circulate through the solar collectors in the existing filter and heating loop. When energy is being demanded to heat the pool, the water will flow into the filter and existing heater, then top up what is needed to heat the water to your desired set temperature. In turn, if the solar is supplying the needed temperature the now secondary backup heater will not have to be used. When your pool is at the required temp the system simply bypasses the solar loop to prevent overheating.

A closed loop solar pool system is a pressurized system separate from the pool loop. Instead of using water, the fluid used in the collectors is an environmentally friendly antifreeze solution containing water, propylene, and glycol. This mixture circulates through the collectors then transfers the heat energy to the pool water via a stainless steel or titanium heat exchanger. The pool circuits meet up in parallel through the heat exchanger where solar energy is transferred to the pool water through the collector system. Any additional energy required is supplied by the existing heater before returning to the pool. To protect the system from overheating, the circulating pump is turned off putting the system into a “Stagnation” state. The fluid in the collectors turns to steam which is then absorbed by the added expansion tank in the loop. This system is more commonly used in colder climates, year-round pools as well as indoor solar pool heating setups.