Experimental study on lauryl alcohol/expanded graphite composite phase change materials for thermal regulation in building

•The LA/EG is placed in the ceramic tiles.•A two-level human thermal comfort temperature evaluation index has been proposed.•The most suitable phase transition temperature throughout the year is proposed.•The time of the comfortable temperature zone is extended during the heating process and the cooling process. The application of phase change materials (PCMs) in buildings has received extensive attention in recent years because they can improve indoor thermal capacity and solve the problem of high energy consumption through their greater latent heat. This study proposes to place the PCM in the ceramic tiles to solve the problem of high energy consumption in buildings based on the comfortable temperature of the human body. We introduced a two-level human thermal comfort temperature evaluation index, and consider that the phase change temperature of 24 °C has the best effect on thermal comfort and the whole year energy saving and emission reduction. Then, we built a building model with ceramic tiles filled with lauryl alcohol/expanded graphite and tested its thermal performance. In this study, lauryl alcohol can increase the heat capacity of the room, and lauryl alcohol/expanded graphite can improve the thermal response speed. We also inlay insulation boards between the wall and the ceramic tiles to prevent indoor and outdoor heat exchange and reduce indoor temperature fluctuations, which helps to keep the indoor temperature within a comfortable range for the human body. Compared with the insulation building, this method can extend the time of the indoor temperature in the comfortable temperature zone by 561% during the heating process, and the time of the cooling process can be extended by 471%. This work can reduce the opening time of air-conditioning equipment, so as to achieve the purpose of energy saving and emission reduction.