Study of external shading on east-facing and west-facing windows in Nanjing

East-facing and west-facing windows in Nanjing were regarded as research objects,and annual availability heat-gain from the solar direct radiation have been selected for evaluating,horizontal shading and vertical shading have been studied.The results showed that,on the basis of different requirements for solar heat-gain in winter and in summer,horizontal shading was recommended for east-facing and west-facing windows in Nanjing.The device dimensions for east-facing windows:the width of shading device should be 0.7 m,the distance between shading device and upside of windows should be 0~0.2 m and extended length should be 0.1 m.Horizontal shading effects of west-facing are better than east-facing,the width of shading device can be increased as much as possible under the appropriate condition,H′=0~0.3 m,L′=0 m.Vertical shading was not recommended without enough obvious effects.