Thermal performance of thermochromic smart windows in different indoor environments

Thermochromic (TC) smart windows can passively respond to the exterior and interior temperature, which further adjust their indoor thermal environments due to the varied photo-thermal parameters. This study investigated the thermal performances of practical TC windows in a room with/without air-conditioning or with stratified temperature distribution through a validated 3D CFD model. The application of TC windows could decrease the window, indoor ambient and floor temperatures, and also improve their temperature uniformity. The upper interior window could be 3.13 degrees C higher than the bottom in a room without air-conditioning, which could be reduced to 2.48 degrees C if the TC window was utilized. The uniformity improvement could be more significant for indoor environments with apparent air temperature differences, especially for the air-conditioning case. It is suggested that the indoor air temperature and its uniformity may affect the temperature and uniformity of the TC window surface in turn, specifically its phase transition time.