Optimal control of natural ventilation as passive cooling strategy for improving the energy performance of building envelope with PCM integration

• Published in: Renewable energy 2020-12, Vol.162, p.171-181
• Main Authors: Piselli, Cristina, Prabhakar, Mohit, de Gracia, Alvaro, Saffari, Mohammad, Pisello, Anna Laura, Cabeza, Luisa F.
• Format: Article
• Language: English
• Subjects: Building energy simulation; buildings; climatic zones; cooling; energy efficiency; melting point; Natural ventilation; Optimization; Passive cooling; PCM; Phase change material; phase transition; renewable energy sources; residential housing; temperature; thermal energy; Thermal energy storage
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2020.07.043

Phase Change Materials have been acknowledged for their potential to be used as passive strategy for improving energy efficiency and occupants’ thermal comfort in buildings. However, their performance still needs to be enhanced to have them effectively used. In this view, this study investigates the potential improvement of PCMs performance for passive cooling application by efficient natural ventilation in residential building stock. Therefore, coupled dynamic simulation and optimization analysis is performed to explore the optimum melting temperature of PCM integrated in the external building envelope to minimize cooling loads in different Italian climate zones. Moreover, various natural ventilation control strategies are implemented to assess their influence on the process of PCM charge-discharge cycle. Results show that PCM inclusion in the building envelope provides significant cooling savings, up to about 300 kWh/year in mild climates. Furthermore, both night and temperature controlled natural ventilation are able to enhance the efficiency of PCMs thermal energy storage charge-discharge cycle. However, the optimum performance is obtained by coupling PCMs with natural ventilation controlled by indoor/outdoor temperature difference in all considered climate contexts. Accordingly, considerable building cooling energy need reduction is achievable through the optimum combination of PCMs and natural ventilation control, especially in milder climates. •PCM passive cooling performance coupled with natural ventilation control is studied.•Summer optimum PCM melting temperature is explored via optimized dynamic simulation.•PCM is included in the building envelope in various Italian climate zones.•PCMs provide significant passive cooling contribution, especially in mild climates.•PCM coupled to T-controlled natural ventilation further improves energy saving.