... harmony with the building perfectly 4) Intelligent control and automatic operation 5) Anti-freeze: no water inside the tubes when ... /19mm,optionalHeat exchanger materialCopper, stainless steel, optionalFree components:Electric heater, Magnesium rod, T/P valve, Pressure reducing valve Water Tank Performance ... : RS15/6 14. Range of environment temperature: -10-50C 300liters Heat Pipe Solar Water Heater