The radiation mainly happens on the glass surface, and the transmission on the window frames and glass.The air leakage is mostly owing to the improper window structure or bad sealing.

• 其中，辐射及对流传递主要集中在玻璃上，传导传递主要在窗框及玻璃,而空气渗漏则大部分是由门窗结构不合理或密封材料品质不佳造成的。