Application of phase change material foam composites in the built environment: A critical review

Phase change materials (PCMs) are applied to the interior of building components to derive their benefit of high latent heat for efficient thermal management. However, their practical use requires proper encapsulation to minimize leakage that could lead to a drop in latent heat and prevent odour concerns resulting from PCM exudation. One method of encapsulation is done in combination with polyurethane (PU) foam, usually used for insulation. The techniques used are broadly classified as indirect and direct incorporation of PCMs in PU foams. The indirect method involves the use either of containers (macro-encapsulation) or of shell-like polymeric material (micro-encapsulation) to prevent leakage. The direct incorporation techniques are classified into: (i) adsorption of liquid PCM on already fabricated PU foam through a post-impregnation process, and (ii) polymerization of PU with PCM at the mixing stage. Nevertheless, each method has unique benefits and shortfalls. In this paper, various interventions on the production of PCM foam composites, traditional and state-of-the-art insulations and their application issues are reviewed and their potential for application is discussed. Factors influencing their fabrication and impact on building energy management, challenges and future direction of research are discussed. The study indicates that weather conditions, geographical orientation, insulation used, and thermal mass of building envelope are the parameters that influence energy consumption in the built environment. It is understood that further research and practical implementation of the PCM foam composites sustainably could pave the way for their commercial use in the built environment.