Experimental study of heat transfer characteristics of phase change material–filled glazed windows

Abstract

The inclusion of phase change material (PCM) in glazing unit is an effective method to reduce energy consumption in building by absorbing a portion of the solar radiation for thermal energy storage while allowing visible light to reach the inside environment for daylighting. This results in reduction in fluctuation of temperature and improved thermal comfort for indoor occupants. There is limited published research, for calculating the heat transfer characteristics of the PCM used in the glazing units, especially under climatic conditions prevailing in India. In this work, the heat transfer characteristics of a PCM-filled double glazing unit were analysed experimentally. The heat transfer performance of the PCM-filled double glazed window unit was experimentally studied and compared with that filled with air, water, and a single glazed window. The experiment was carried out on different days for each window unit to find the temperature of inner and outer surface of glazing and also heat flux through the glazing. The result shows that PCM filled double glazing can minimize the inner surface temperature of the window by four degrees below the outer surface temperature in the morning, compared to air and water-filled double glazed windows. However, air and water-filled glazing are only capable of reducing inner surface temperature by a maximum of two degrees. Thus, a PCM-filled double glazed window can efficiently reduce the inner surface temperature than a single glazed window, air, or water-filled window.