Investigation of the impact of phase change materials at different building envelope placements in a semi-arid climate

Researchers in the building industry are becoming increasingly interested in phase change materials (PCM). Due to the potential for passive temperature management offered by these PCMs, HVAC (Heating, Ventilation, and Air-Conditioning) equipment will use less energy. Still, to prevent leakage during phase change, an enclosure is needed when installing PCMs in buildings. So, to determine this passive indoor temperature regulation cost, payback period, and energy savings, it is crucial to assess the PCM energy savings in various building envelope placements. So, this is done by using the EnergyPlus simulation engine for the case of the commercial PCM RT 28HC, this article will assess and compare 8 potential building envelope positions in a semi-arid region. These eight different building configurations have one case without PCM and the other cases have PCM placed in the interior surface of the following specific placements, a PCM placed in walls envelope only, in floors envelope, in ceilings and roofs envelope only, in walls, ceilings, and roofs envelope, in walls and floors envelope only, in floors, ceilings and roofs envelope and all envelopes for a 10 m square-shaped building. This study's primary goal is to evaluate the reduction of indoor air temperature fluctuations, PCM energy savings, PCM activation, and payback period for these various building layouts. The findings show excellent temperature indoor stabilization in summer, for the case with PCM installed on all interior envelope surfaces showing a maximum indoor temperature fluctuation decrease of 110.2 °C for August. In addition, the case with the PCM placed only in the walls, roof, and ceilings has shown the highest yearly energy savings, nevertheless, the case with PCM placed only in the walls has the lowest payback period of nearly 22 years and a half.