The energy-saving effect of aluminum alloy door and window frames is close to that of steel and plastic window frames, but because of the difference in material, steel and plastic windows are prone to deformation after a period of time, and their sealing performance is not as good as high performance alu aluminum door design.  

Because steel model window pledges material intensity and steel are low, although through processing lining steel is enhanced, but its fight wind pressure and watertight performance want to compare aluminium window low about 2 grades, be in performance respect so, the grade of aluminium door window wants higher than steel model window.