Building heating applications with phase change material: A comprehensive review

Energy crisis and environmental problems motive a variety of research strategies to increase energy efficiency, decrease stress on energy infrastructure, and consequently reduce CO2 emissions. Improving efficiency of building heating applications by advanced techniques such as solar collectors and heat pumps, is considered as one research strategy. Utilization of phase change material (PCM) with the virtue of high energy storage density is another research strategy. However, a comprehensive review for intergrating these two research strategies, namely building heating applications with PCM, is still lacking. This study presents a comprehensive review of research works for these applications including PCM roofs, ceilings, and walls, PCM windows, PCM floors, solar chimneys with PCM, solar heating applications with PCM, heat pump applications with PCM, and electrical heaters with PCM. Research development for these passive and active applications including key findings, is sufficiently presented. Summaries and discussions are conducted to identify research gaps for each application. To better utilize the PCM, PCM types, encapsulation forms of PCM, and types of PCM units in these applications are analyzed and discussion. Research methods used in these review literatures are summarized and discussed to further determine research possibilities and limitations. Important conclusions and future recommendations for the research of these applications are given to guide scholars to perform further advances in research.