Hi, in my solar system the water comes out from a tank and enters the solar collector at 20 C but it exits colder! (during day hours it heats up but it always remains colder than the inlet temperature of the collector)
i can't understand why at the beginning the water that exits the collector is at 0 C (and then slightly superior: 3-4 C)
During day hours it rises till 17 C, but it remains always less than the 20 C of the inlet water to the collector!