Investigating the Influence of Thermal Conductivity and Thermal Storage of Lightweight Concrete Panels on the Energy and Thermal Comfort in Residential Buildings

Phase change materials (PCM) are integrated into lightweight concrete (LWC) panels to increase their thermal mass. However, the integration of PCM into LWC also increases the thermal conductivity of the panels, which may have a negative impact. This study investigated the impact of thermal resistance and storage of LWC panels on thermal comfort and energy use in buildings. Six different LWC panels with varying levels of thermal conductivity and storage were developed using various combinations lightweight aggregates and PCM. The experimentally measured properties were used in building simulation software EnergyPlus V9.3 to calculate overheating and building energy consumption for each panel. The result showed that thermal mass influences severe discomfort hours more than thermal resistance. However, the level of influence depends on the position of the panels compared to the insulation layer. The presence of an insulation layer reduced the energy savings rate. The cooling energy consumption was more influenced by the thermal mass, whereas the heating was more influenced by the resistance of the wall. Overall, the LWC panel with the highest thermal mass was the best to reduce severe discomfort hours and energy consumption despite having the highest thermal conductivity. The outcome of this study can help to design an external building envelope with PCM panel as per user requirements, which could be to reduce overheating or cooling only, heating only, or both cooling and heating.