Thermal performance simulation of buildings’ envelope with micro encapsulated Phase Change Materials (mPCMs)

Wooden constructions are gaining popularity due to their economic benefits and their lower embodied CO2 emissions. However, wood buildings face certain challenges, with one prominent issue being their limited thermal mass, resulting in lower thermal inertia within these structures. The scope of the study is to develop a simulation model in COMSOL Multiphysics (CM) to reflect the performance of buildings when PCMs are used in the structures. The model is validated with experimental data and then used to determine the optimal position of PCMs in a multi-layer wall, in addition, the optimal thickness of mPCMs has also been studied. The model in CM, representing a building with the shape of a box, consists of two versions. The first version (named as test box) is modelled with 5 sides of pure gypsum and 1 side of PCM-gypsum composite. The second version (named as reference box) is modelled with 6 sides of pure gypsum. These models are experimentally verified in the study. The study is focused on reducing the cooling load, the PCM gypsum composite material should function effectively during summer conditions in northern Sweden. A climate chamber is utilized to create temperature conditions of summer days in northern Sweden for the two boxes while performing measurements to validate the simulation model. Result indicates a slightly lower temperature value from CM in comparison to the experimental data. It also shows the optimized position of PCM layer is the internal surface of the room and the thickness is important to be considered depending on the location.