Analysis on the Effects of Thermal Properties of External Windows on Cooling Energy Consumption and Efficiency of Buildings

The building environment simulation software DeST-c was used to analyze the effects of thermal properties of external windows on the cooling energy consumption and efficiency on the base of an office building in Guangzhou.The results show that decreasing the shading coefficient of external windows can significantly reduce the cooling energy consumption.As the shading coefficient of external windows decreases from 0.9 to 0.2,the cooling need of the office building reduces by 26%.However,the heat transfer coefficient of external windows has little effect on the cooling energy consumption.Furthermore,the mechanism of the reduction of cooling energy consumption caused by the decrease of the shading coefficient was also studied through the hourly analysis on the cooling energy efficient rates all the year round.It can be found that the cause of the significant increase of annual cooling energy efficient rates is that as the shading coefficient decreases,the hourly cooling energy efficient rates increase significantly for the hours with higher cooling load.These results can provide references for the building energy efficiency in hot summer and warm winter zone.