Thermal performance of radiant floor systems incorporating phase change materials: effects of latent heat and phase change temperature range

The thermophysical properties of the Phase Change Materials (PCM) incorporated in building applications, especially in radiant floor systems (RFS), are instrumental to improved performance. To maximize PCM effectiveness, it is essential to understand how different thermal properties influence the behaviour of both the PCM itself and the PCM-RFS. A gap in the literature exists regarding the extent to which the phase change temperature range and latent heat of the PCM influence its performance and efficiency when incorporated into RFS. Thus, in this study, a two-dimensional PCM-RFS numerical model was developed using Ansys Fluent®. The model accuracy was ensured through independence tests and validation against experimental data. A reference peak melting temperature of 27°C was adopted, and the influence of three phase change temperature ranges (±1°C, ±2°C, ±3°C) and four latent heat values (50–200 kJ·kg −1 ) of the incorporated PCM on the thermal performance of the PCM-RFS were analysed. Results indicate that case studies characterized by lower latent heat of fusion exhibit faster melting rate and reach higher liquid fraction, whereas narrower phase change ranges result in less mobilization of the incorporated PCM, under the studied conditions.