Fundamental Study on the Optimal Design of a Folding Shading Device: Solar Radiation Model & Potential Cooling Load Saving

Abstract

This study was performed to evaluate the thermal performance of a Folding Shading Device (FSD), focusing on analyzing the effects of cooling load reduction through computer simulation for the system when it is installed on the south facing wall of a building. The results demonstrate that the use of the FSD allows simultaneous consideration of the altitude and azimuth of the sun, while the projected length of the shade can also be adjusted. A mathematical model for the calculation of the shaded area provided by the FSD by considering the size of the fittings was therefore suggested. In addition, the performance evaluation revealed that the installation of existing types of horizontal, vertical, and lattice shading devices installed for the cooling period in a building would lead to the reduction ratios of solar radiation of 17.45-46.98%, 4.70-14.77%, and 26.17-75.17%, respectively. However, the FSD showed the greatest reduction ratio of 22.15-61.74%. In addition, the reduction ratios of cooling loads for the existing horizontal, vertical, and grating shading devices were 6.72-17.23%, 1.68-5.46%, and 10.08-26.89%, respectively, while the FSD achieved the greatest reduction ratio of 8.40-21.85%. Therefore, if the FSD suggested in this study is applied to a building, it can be expected to achieve reductions of the cooling load, thus contributing to the reduction of greenhouse gas emissions.