Dynamic coupled heat transfer and energy conservation performance of multilayer glazing window filled with phase change material in summer day

Windows as indispensable for buildings play an important role in decreasing building energy consumption and improving indoor thermal comfort. However, the conventional windows made of the pure glazing units fail to meet the requirements of energy conservation for buildings due to poor thermal insulation. Recent researches found that the application of phase change materials (PCM) can improve the heat transfer performance of glazing unit and the PCM-filled glazing units have advantage in reducing building energy consumption and improving indoor thermal comfort. Therefore, the dynamic coupled heat transfer and energy conservation performance of PCM-filled multilayer glazing unit are investigated numerically in this work. A transient coupled heat transfer model considering conduction, phase change and solar radiation transfer in glazing unit is established, and the energy conservation performance is analyzed based on the heat transfer calculation. Results show that the PCM-filled multilayer glazing unit can significantly reduce energy consumption compared with pure glazing unit, and the energy saving rates are 14.55% for double glazing unit, 33.89% for triple glazing unit and 50.71% for four glazing unit, respectively. In addition, the effects of optical and thermal parameters of PCM on thermal performance of glazing units are investigated thoroughly. It is found that the PCM-filled multilayer glazing unit has advantages in thermal insulation which is good choice for transparent envelope in the building fields.