... .Domestic rooftop solar water heater 2.Easy to be installed 3.CE,ISO9001,ROHS,Solar Keymark,SRCC,approved 4.OEM is ... solar tubes; 2) Copper heat pipes for rapid heat transfer; 3) Easy plug-in installation; 4) Free maintenance; 5) Suitable for mains ... is absorbed by the solar tubes and converted into heat. 3) Solar heat transfer: heat pipes conduct the heat from within ...