INVESTIGATION ON THE EFFECT OF PCM LAYER THICKNESS IN DOUBLE GLAZED WINDOWS

Abstract

Green building design is gaining popularity due to the environmental impact of today’s energy sources, which rely heavily on fossil fuels. The construction and industrial facilities sector accounts for up to 40% of worldwide energy demand. Heating, ventilation, and air conditioning (HVAC) systems are responsible for more than 60% of overall energy usage in buildings, with glass windows being the primary source of heat load. Windows cannot be avoided in a structure, as they are an essential aspect of a building for obtaining natural light. This study investigates the effect of phase transition or melting temperatures of phase change materials (PCMs) when used in double-glazed windows and their impact on heat and light transfer characteristics, using experimental and numerical methods. The PCMs used for this study are OM42 and OM 50. PCMs acts as latent heat storage units and reduce the heat in leak to the inner space. The objective of this study is to limit the amount of heat transfer through the glass provided in windows. The developed experimental setup is having the provision to change the glass thickness and to fill different PCM’s. Experiments were conducted by varying PCM layer thickness to determine the glazing’s inner and outer surfaces temperatures in a controlled environment. ANSYS FLUENT software was used to conduct the numerical analysis and the results obtained were compared with the experimental results for validation. The main property taken for the study is the phase transition temperature of the PCM. In this study it is observed that the heat transfer through the window to the room is mitigated by PCM through its phase change, which in turn leads to the decrease in room temperature. Since the solidification of the liquid PCM happens slowly, the glazing’s ability to transmit light is unaffected. This can be achieved by properly fixing the thickness of PCM. It is also observed that, the glass thickness is having significant effect on the performance of PCM’s. This study explores the potential of PCM that can be used as a filler material for double-glazed windows to reduce the fluctuations of room temperature thereby increasing the comfort.