Study on influencing factors of diffuse solar radiation on vertical surface

Solar radiation on the building facade is one of the main meteorological factors that affects the building energy consumption. Analyses the main factors which affects the diffuse solar radiation on vertical surface using the real data observed at the radiation station. Finds out the correlation among diffuse solar radiation on vertical surface, clearness index Kt, direct radiation transmittance Kn and angle between the direct normal solar radiation and the normal direction of the vertical surface φ. The results show that with the increases of Kt, Kn and φ, diffuse solar radiation on the vertical surface increases firstly and then decreases. But the ratio of vertical diffuse radiation to horizon diffuse radiation K is proportional to Kt and Kn and inversely proportional to φ.