Analysis of the Thermal Response of a Floor Heating System Incorporating a Phase Change Material

The rapid urbanization and the increasing demand for indoor comfort have resulted in a rise in energy consumption and a negative impact on the environment within the building sector. A promising approach to improving energy efficiency is the integration of phase change materials (PCM) into underfloor heating systems. This study aims to assess the impact of PCM integration on the thermal and energy performance of a hydronic floor heating system. To achieve this objective, a two-dimensional numerical model was developed using COMSOL Multiphysics software. The finite element method, combined with the effective heat capacity approach, was employed to accurately simulate the thermal behavior of the system. The influence of several parameters, such as PCM type, thickness, and position within the floor structure, was analyzed to optimize system performance. The results reveal that integrating a 3 cm thick salt hydrate-based PCM, with a water supply temperature of 40 °C, significantly improves the thermal inertia of the floor. This configuration ensures a comfortable temperature (~27 °C) even after the heating system is turned off, with a time lag of 17 hours compared to a floor heating system without PCM. These findings highlight the potential of PCM in underfloor heating systems, offering an effective solution to reduce energy consumption in buildings while maintaining optimal thermal comfort.