Modeling and analyzing the optical and thermal performance of window with transparent insulation slats

Abstract

In order to achieve the sustainability of the built environment, extensive efforts have been made to improve the performance of glazed facade systems, thereby increasing indoor comfort and building energy conservation. A kind of window with transparent insulation slats (WTIS) is promising to achieve improved optical and thermal performance. In this study, an optical and thermal model of WTIS was established and the validity of the model was verified by experimental data. The impact of various influential factors on optical and thermal performance of WTIS was analyzed. The results show that the total transmittance decreases and the solar absorptance of transparent insulation slats (TIS) increases with the absorptivity of slat surface (αsl) and the ratio of slat width to the distance between two adjacent slats (W/L ratio). When the slat spacing increases from 10 mm to 25 mm and the slat width is 20 mm, the peak instantaneous heat flux and k-value of WTIS increase by 30.57 % and 17.54 %. When the transmissivity of slat surface increases from 0.1 to 0.7, the peak instantaneous heat flux and k-value of WTIS increase by 25.13 % and 5.31 %. Besides, the variation of shining factor has little effect on the total transmittance and the solar absorptance of TIS. The total transmittance and the solar absorptance of TIS have linear correlation with the proportion of diffuse radiation.