Experimental comparisons on optical and thermal performance between aerogel glazed skylight and double glazed skylight under real climate condition

Abstract

Skylights are increasingly used in modern buildings, whereas few studies focus on the performance of aerogel glazed skylight (AGS) under real climate conditions. In this study, a comparative experiment between AGS and double glazed skylight (DGS) was carried out under real climate conditions in Changsha, China. Outdoor and indoor solar irradiance and illuminance at the AGS and DGS sides were measured to show the optical performance. The results showed that the solar radiation reduction rates of AGS compared to DGS in summer and winter are about 48% and 64%, respectively. The illuminance reduction rates of AGS compared to DGS in summer and winter are about 35% and 64%, respectively. The temperature of each layer of AGS and DGS was also measured. Through analyzing the temperature distribution, it is found that the temperature distribution in AGS is significantly influenced by the absorption of aerogel to solar radiation, especially in summer sunny days. The maximum temperature differences between the aerogel layer of AGS and the air layer of DGS is 6.64 °C in summer. By comparing the total heat gain/loss through AGS and DGS, it is found that the energy-saving ratio of AGS compared to DGS is 37% in summer, and AGS is suitable to be used in the overcast-dominated climate zone in winter. Therefore, AGS installed horizontally on the roof is energy efficient in the hot summer and cold winter zone in China.