Study on SHGC Calculation and Measurement of Window Installed with Shading Device

Abstract

The Solar Heat Gain Coefficient (SHGC) is one of the energy loss factors in buildings, which affects a cooling load significantly. A variety of shading devices and high-performance windows have already been developed and applied to a large number of buildings to reduce a cooling load. However, performance evaluation on these shading devices and high-performance windows has depended on calculation via mathematical models and simulations. These evaluation methods have limits when reflecting heat characteristics of the ever-increasing complexity and development of window systems accurately in a realistic way. Thus, it is critically necessary to verify performance evaluation results through actual measure. The purpose of this paper is to measure the SHGC of various types of windows and shading devices and to analyze the difference between the calculated value and the measured value. The experimental result is as follows. SHGC of venetian blind is lower than SHGC of roll screen and Triple shade. The higher the glass SHGC was, the higher the SHGC reduction rate was under the same condition. The larger the slot angle was, the greater the SHGC performance improved. The analysis result on measured and calculated values showed that a mean different ratio was 4.86 %, which was matched within 5 % of the deviation rate. However, the different ratio tended to increase as the complexity of structures and types of windows increased.