Phase Change Materials Integration in Building Envelopes Under Different Climatic Conditions: State of the Art, Opportunities, and Challenges

Building envelope has a pivotal role in adequate thermal comfort of occupants in the indoor environment. Recent research has been focused on innovative techniques to enhance building performance. Among them, the integration of phase change materials (PCMs) in building envelopes has proven to be promising. Phase change materials have the potential to tune the temperature around their melting point. In addition, the latent heat of phase transition provides high storage capacity compared to plain envelope structures. The current paper provides a comprehensive review on PCM inclusion in building walls, roofs, and floors. It highlights the main governing performance parameters, incorporation methods, modeling techniques, and thermal performance assessment of the systems. Detailed analysis of the results is presented. It includes the effect of PCM inclusion on cooling/heating load reduction, indoor thermal comfort conditions, and energy saving. PCM inclusion was found to reduce building loads by up to 30%. They have also shown a potential of maintaining indoor temperature fluctuation within as low as 2°C. The listed papers cover the recent few decades and span through locations with different climate conditions. The majority of reported work was in Europe and Asia as they are leading in their sustainability goals. In adverse climates like North America, scarce research was reported as the large temperature variation is not favorable for PCM integration. The paper is intended to be a guide for researchers working in the field of PCM integration in building applications. It covers the most recent advances, potentials, and challenges of different integration techniques.