Lessons in Solar Pool Heating
Your Solar Pool Heating Choices
Boxed and glazed
Hot Sun unglazed collectors
Hot Sun technology is the most efficient solar collector
In the solar energy world solar swimming pool heating is most commonly done with what is called an unglazed collector. This refers to the fact that there is no glazing (glass) over the absorber surface. Its because at swimming pool temperatures this type of collector is the most efficient meaning it collects and delivers to the pool the highest percentage of the sun’s energy. Glazing and insulation only helps when the water is hot compared to the air. If the pool is the same temperature as the air for example, the glazing will actually reflect some of the energy away. The solar collector’s efficiency is dependent upon the air vs pool temperature as well as strangely, the actual intensity of the sun. These are the efficiency curves for the various types of solar collectors. Note that unglazed like our Hot Sun technology is actually more efficient close to the y axis where we most often heat pools.
Evacuated tube and boxed and glazed collector types operate more efficiently at higher water temperatures like we see in the application where we are preheating domestic hot water. Learn more about solar hot water heating. If the load is high enough we can preheat hot water with unglazed collectors more effectively because hot water is already hot. We have to heat water from cold to hot and when cold, unglazed collectors are more efficient and far less expensive.
Why not heat the pool with a heat pump powered by excess electricity from your photovoltaic solar system? Let's study this question.