Optimization of a ceiling ventilation system with integrated photovoltaic thermal collectors and phase change materials

This paper presents the performance evaluation and design optimization of a ceiling ventilation system with integrated solar photovoltaic thermal (PVT) collectors and phase change materials (PCMs) by using a hybrid Particle Swarm Optimization and Hooke-Jeeves Pattern search (PSO-HJ) algorithm. In this novel ceiling ventilation system, the PVT collectors are used to generate electricity and provide the low-grade heating energy for buildings by using the winter daytime solar radiation, while the PCM is integrated into the building ceiling as part of the ceiling insulation and at the same time, as a centralized thermal energy storage unit to temporally store the low-grade thermal energy collected from the PVT collectors and use it later when needed. The benefit of using this proposed PVT-PCM integrated ceiling ventilation system in active buildings with air-conditioning systems was evaluated in terms of the total power consumption of the house for space heating. Further optimization was performed in order to identify the optimal values of the key design parameters. In the hybrid PSO-HJ algorithm used in the design optimization, the PSO is first used to identify the optimal region of the design variables while the HJ algorithm is then used to perform a local search to identify the "global" optimal values. The results showed that the integration of PVT collectors and PCMs with the ceiling ventilation can greatly reduce the power consumption of the house for space heating in winter. By employing the optimal design identified using PSO-HJ algorithm, the power consumption of the house can be further reduced.