Thermal performance of PCM-glazing unit under moderate climatic conditions

Syracuse, NY

Considering physical properties, transparent or translucent building components like windows or glazing facades are the weakest elements of building envelope. The heat transfer coefficient of such elements is approximately four times higher than for opaque partitions, which causes considerable increase of heat loss during winter. In summer relatively high solar transmittance is a source of heat gains which results in undesirable overheating. Application of phase change materials in glazing components affects its thermal performance by the increase of its heat capacity and decrease of solar heat gains, with regard to the current physical state of the PCM. The aim of this paper is investigation and determination of the thermal performance of PCMglazing unit, under real, moderate climatic conditions in summer season. Analysis conducted by the authors aims to find the proper arrangement of PCM-glazing unit and proper material properties design, allowing effective overheating control. To meet the stated goals, dynamic simulations of thermal performance of triple-glazing unit were carried out, using ESP-r software. It was assumed that one chamber, filled with PCM will adjust the solar heat gains flux while the second one will assure required thermal resistance of the partition. Original model of heat transfer through transparent partition, taking into account latent heat storage by effective heat capacity method was applied. Different phase change materials, characterized by various phase transition temperatures were considered in the analysis. Based on the obtained results it can be concluded that application of a PCM in the external cavity of the triple glazing window effectively affects the thermal performance of the component, stabilizing the diurnal temperature fluctuations. Simulation results revealed that transition temperature should be close to the assumed cooling set point.

https://surface.syr.edu/ibpc/2018/BE10/6