How does a solar pool heater work? First of all, a solar pool heater is not a solar powered, electric pool heater, essentially doing the work of a standard pool heater without the same impact on your electric or gas bill. However, solar pool heaters do use solar energy to warm your pool no matter which design you use.
One version of the solar pool heater design puts solar energy collectors on your roof that capture and retain the sun’s heat, using it to heat water. This warmed water is pumped into the pool. The main advantages of this design is that it requires almost no power compared to a conventional pool heater and doesn’t force you to install batteries and complex electrical systems in order to have an eco-friendly source of heat for the pool. You can combine a solar pool heater with a conventional pool heater to keep the water warm while minimizing the impact on your utility bills. If you live in a hot climate, the solar pool heater system can also be used to cool water in the pool by circulating the water through the collector at night. Depending on the design, you may not need an extra pump and can run it off the pool pump. This will raise the pool pump pressure when the solar pool heater is in use, though.
This type of solar pool heater can have glazed or unglazed panels. If the pool will only be used when temperatures are higher than the freezing point of water, you can use an unglazed solar collector system. Unglazed systems don’t have a glass covering. They use either rubber or UV treated plastic. The advantage of this system is its lower cost over a glazed system, and you can make it maintain a pool’s warmer temperatures even better by combining it with a pool blanket. Unglazed systems may work for indoor pools if the system is designed to drain warm water into the pool if the system is not in use so that you don’t have water in the collectors that could freeze, expand and damage it.
The main disadvantage of these systems is that they have to be shut down in cold weather in most installations, so it simply extends the swimming season instead of letting you use the pool year round. Glazed systems put a layer of glass above the solar collector tubes which are themselves made from copper tubing on top of an aluminum plate. These systems can often be used even in freezing climates and year-round, with the added benefit of being even more efficient at harvesting solar heat. Their biggest disadvantage is their price. If the glazed system needs to be half the size of your pool to help raise its temperature 10 degrees to 15 degrees, the unglazed system will need a surface area about as large as the swimming pool itself.
Another design of solar pool heater is built into the pool cover. Called solar pool covers, they insulate the pool to prevent the loss of heat overnight and trap sunlight during the day to help warm the pool. The advantages of solar pool covers include being able to use it even if you don’t have the good southern exposure necessary for the first type of solar pool heaters, not worrying about voiding your roof’s warranty by putting hardware on the roof and don’t require complicated piping or motors to work.