Effects of PCM application on thermal and energy performance of buildings in summer

The paper presents an investigation of the effects of implementing phase change materials (PCM) at the room facing side of internal and external walls on the thermal and energy performance of residential, school and office buildings. Two construction types for residential buildings were studied: (1) a heavyweight concrete structure with concrete infill walls covered by cementitious renderings, and (2) a lightweight steel structure with lightweight external walls and gypsum wallboard partitions. For the school building the investigation addressed a heavyweight structure composed of precast concrete panels with two alternatives for the thermal insulation: (1) on the outer surface, below a stone cladding, and (2) on the interior side, behind a gypsum wallboard surface covering layer. For the office building the most typical construction type was investigated, which includes a column and beam structure with lightweight external walls and interior partitions. The main results are: (1) when the building includes a sufficient amount of internal mass, the addition of PCM improves thermal comfort during occupancy hours, but does not improve energy performance. (2) When the regular mass is very small, or not available for energy buffering at the room facing side, PCM improves both, thermal performance as well as energy performance.