Lightweight Concrete Containing Phase Change Materials (PCMs): A Numerical Investigation on the Thermal Behaviour of Cladding Panels

The use of phase change materials (PCMs) in building elements has gained increasing popularity in recent years because of the potential energy savings that result from the heat stored during variable temperature–time histories. This paper describes the results of non-linear numerical analyses on sandwich panels characterized by different geometry and consisting of an innovative concrete, i.e., lightweight concrete with aggregates containing PCMs. The amount of embedded PCMs has no equal in the literature, and this calls for a detailed assessment of its thermal performance within a typical building element. The heat transfer process inside the panels is modelled via finite elements in order to evaluate the effectiveness of the addition of PCMs with regard to insulation. The results show that adding PCMs may significantly reduce (by up to 20%) the energy required for cooling in the hot season, while the reduction of the energy required for heating in the cold season is lower (up to 10%). Moreover, there is a significant reduction in the instantaneous power required, both for heating and cooling.