... The perfect solar collector for domestic solar water heater system11.Ideal for commercial solar water heating applications.Heat pipe solar collector work ... Alloy,Thickness,1.8mm,Insulating layer,compressed rock woolHeat Pipe pure red copper TU1+water,transfer power>=150W,Working ... boron and silicon content 3.3,Structure,Gradual change SS-AL-Nx/Cu selective absorption coating,Vacuum Degree,P<=5* ...