Exploring The Relation Between Daylight And Lighting For Large Depth Offices In Beijing

China is one of the fastest growing countries in energy demand in the world,and the second-biggest energy consumer behind the United States. So energy conservation is of great significance. Natural light has been an important aspect for building sustainable development. Offices have been the major components of public buildings in our country. As land is a scarce resource, and large-depth offices are popular, daylight for large-depth locations need to be valued, Here are five aspects about this subject:Firstly, sidelight elements and technical means of energy-saving lighting is interpreted. The classification of office buildings is explored; the style of offices is described; analyzing day lighting performance under different window styles;Secondly, the software description is done. After the comparison of different softwares, Daysim and Diva for Rhino are the calculation tools.Thirdly, daylight energy-savings methods of offices are described. Many effects have relationships with DA450, such as surface reflectance, glass transmittance, orientation, shape of the window, window sill height, depth and so on.Fourth, based on the method of’Standard for daylight design of buildings’, daylight energy-savings potential k for231rooms are calculated, which is an indicator used to interpret daylight energy-savings potential all year. Finally, the area which daylight is used partly is analysed. Daylight is performed based on yearly daylight. It has a connection with energy-savings. Due to four descriptions, the conclusions of this article include:Firstly, Large-depth office daylight and daylight energy-savings issues should be taken seriously. Also, the awareness should be the first place. The new introduction of daylight technology is one of the trends of future development. Secondly, the comparison of calculated results show that windows shape and position, the floor height and orientation have a huge impact on the daylight level throughout the year.Thirdly, window to floor, total transimittance of window is similarly proportional to DA450. k will enchance with the increasment of the window width and height ratio, and decrease with the increasment of the depth of offices. As office depth is going to be large, the decreasment ratio of k will lower gradually.