Dynamic modelling of the solar radiation exposure effects on the thermal performance of a PCMs-integrated wall

The authors present a dynamic simulation of the thermal behavior of a multilayer plane wall, integrated with Phase Change Materials (PCMs), exposed to solar radiation in summer conditions, in a Mediterranean site. PCMs are a promising kind of heat storage materials that are particularly good in some climatic conditions: if properly placed, they can decrease heat flux through the walls, thus reducing cooling loads in buildings. Due to their strong non-linearity in thermal behavior, PCMs must be carefully modeled, possibly in transient conditions. The dynamic model consists of two main distinct parts. First, a solar radiation model is implemented, based on the daily evolution of the solar angles. This solution uses the results of a novel simple model for splitting the diffuse and the direct solar radiation starting from data on total radiation on a horizontal surface only. Then, solar radiation is used as a boundary condition for the dynamic modeling of a typical multilayer lightweight wall provided with one insulation layer integrated by PCMs. The calculated of solar effect and cooling loads are studied for three different melting temperatures of the PCMs.