Investigating the Effect of Phase Change Materials on Energy Consumption in Lightweight Prefabricated Relief Buildings

In this research, the role of Phase Change Materials (PCM) in energy saving in lightweight prefabricated buildings is studied. For this purpose, a typical building in Kermanshah, Iran is simulated in DesignBuilder software. A split unit is used as air conditioning system. The annual energy consumption of the building in the reference state is 2577.27 kWh. The implementation of the InfiniteRPCM21C was investigated in all directions including each individual wall, ceiling, four walls simultaneously and the entire building envelope. The southern wall is the best option among the walls with 12.14% energy saving. From an economic point of view, this wall has the best performance as well by saving 2.08 kWh/kgPCM. Implementation on the entire envelope increases savings up to 37.2%. Although this is not an economical case, but it reduces the need for energy to almost zero in four months of the year. By examining the PCM in different layers of the wall, it was found that in all directions, the inner surface of the wall leads to the greatest energy savings. Also, taking account the PCM thickness in the range of 5 to 25 mm showed that the smaller the thickness, the greater the savings per unit mass of the PCM. Therefore, thicknesses more than 20 mm are not recommended. Finally, the effect of the PCM melting point in the range of 18 to 29 degrees Celsius was investigated and it was found that the maximum energy saving is obtained at the melting point of 21 degrees Celsius.