Free cooling using phase change material for buildings in hot-arid climate

Abstract

Free Cooling based on Phase Change Materials (FCPCM) are promising sustainable technologies which aim to use the cold night ambient air as a heat sink. The stored cooling in the PCM could be used to offset the heat generated during the daytime. The current work aims to evaluate the feasibility of FCPCM technology in hot-arid regions where the cooling demand is dominant throughout most of the year. A PCM storage system comprising a number of PCM panels has been developed and assessed using Computational Fluid Dynamics modelling utilising ANSYS Fluent. The influence of operating conditions on the system performance was discussed by studying the solidification and melting process characterisation of the PCM. The results indicate that the proposed system is capable of reducing the cooling load substantially and the temperature of air supplied by the system is maintained well within the summer comfort zone of 25.5 and 30°C under the case study climate for up to 14.5 h during the discharging period. However, the system performance is less efficient during peak summer conditions, and a combination with other passive cooling strategies may be required.