the u pipe series solar collector are always connected with existiong heating supply device,the selective coating on the inner cover of the evacuated tube converts solar energy into heat energy and transfers heat to metal u pipe by an aluminum fin. the liquid(usually a glycol-water antiffrddze mixture) in the u pipe heats up.and conducts the heat energy to the water inside the storage tank through plate exchanger or inernal spiral coils.
as the water temperature can be adjusted using an automatic controller,user can get hot water all day long.