Study On Effect Of Window-wall Ratio And Daylighting To Energy Consumption Of Office Building In Tianjin

Worldwide attention was attracted to the energy consumption and environmental problems, so international architecture and lighting take making use of daylighting and building energy saving as emphasis. The window design of a building is always given to in architecture design and the window area has an influence on the daylighting effect and building energy consumption. Big window area is required to get good natural lighting, on the other hand, big window area will increase the solar heat gain, then the cooling energy will be increased. There are many research on building energy consumption in China, however, there are little study on the combination side window and skylights daylighting with building energy conservation, in order to reduce the total energy consumption under the situation of ensuring the intensity of illumination. What's more, the influent of inside and outside shade to the indoor daylighting can't be calculated in the past research, because of the limitation of the software.In this paper, the zero-carbon exhibition center building in Tianjin eco-city was taken as a model to discuss the lighting energy consumption,heating and cooling energy consumption by chancing the design of its window design, such as window to wall ratio, internal and external shading and lighting saving measures of the side windows and skylight window. And finally the relationship between these factors would be got. It is necessary to verify the boundary condition settings of the software Energy Plus before the simulation is conducted. A sunny little room with a southern window was taken as the simulation model to compare the values from the test and simulation.The following conclusions can be reached through simulation analysis: (1) under the condition of the high performance of thermal insulation property and more sunny windows of the office building, solar radiation heat gain from the window is greater than the heat lost through windows, so the heating energy consumption will reduce with the window wall ratio increasing. (2)No matter there is internal or external window shade, with the window to wall ratio of the side window increasing, the total energy saving is not obvious. But the energy savings of external shading is more than internal shading, so external shading should be used in summer. However in the winter internal shading measures should be adopted because external shading will cause more heating energy consumption. (3)On the condition of lighting saving controls, with the side window to wall ratio increasing, the energy conservation ratio of lighting increased, this conclusions indicating that significant effects can be reached by taking energy-saving measures with lighting, especially in case of non shading measures. (4) The use of the skylight to the effect of cooling energy consumption should be greater than the effect of heating energy consumption, so it can't achieve the goal of reducing energy consumption lighting.