Application of Phase Change Materials (PCMs) in Building Walls: A Review

The rapid growth of the population and overcrowded of urban areas forced building construction sector to focus more on economic consideration rather than climatic requirements. As a result, achieving comfortable living spaces was fully dependent on mechanical systems, which caused more energy consumption and greenhouse gas emissions. Passive design strategies become an attractive alternative to tackle this problem and to reduce the negative impacts on our planet. Phase Change Materials (PCMs) store superior amount of latent heat when changing their phase compared to sensible heat. PCMs application in buildings helps to lower indoor temperature and reduce temperature fluctuation and total hours of overheating. Additionally, PCMs can also absorb the internal heat dissipated by household equipment, lightings and occupants' activities. All this help to improve building indoor environment. This paper aims to review PCM applications for building walls. It was found that PCMs might be incorporated to building walls as pre-fabricated PCM-enhanced elements such as PCM-enhanced wallboards, panels, bricks and blocks. In addition, it might be incorporated on the site to fresh mixtures such as concrete, plaster and mortar and applied to buildings. The thermal performance of building walls was improved in all cases resulting in heating and cooling load reductions. Moreover, many researchers found that applying night ventilation further improves the thermal performance of PCMs in building walls.