Influence of new thermal storage schemes based on modular phase change floors on building heating performance

The application of convenient modular construction has become a popular building approach. The modularity of phase change floors (PCFs) provides the possibility for flexible heating and energy storage in buildings. This study designs two new thermal storage schemes based on modular PCFs: cascade and partial thermal storage to enhance the PCFs' heating performance. A PCF simulation model is developed and verified by comparing ANSYS simulation results and experimental measurements. Then, heating and cooling processes of PCF heating rooms using different heating methods (full/local) and thermal storage schemes (full/cascade/partial) are comparatively analyzed. The results show that at full heating, the room's thermal comfort is reduced with cascade and partial thermal storage compared to full thermal storage, but the energy efficiency and economic performance are improved with partial thermal storage. Localized overheating of the floor surface occurs with cascade/partial thermal storage. While cascade thermal storage can enhance the melting of phase change materials (PCMs), low-temperature PCMs are prone to incomplete solidification. Partial thermal storage can save up to 2 % of energy over full thermal storage. In addition, with local heating, changes in thermal storage schemes essentially do not affect the room's thermal comfort. Partial thermal storage still offers the best energy efficiency and economic performance. It has a payback period of less than 6.5 years, which is about 2.6 years shorter than full thermal storage. Rooms with different heating methods have different suitable thermal storage schemes. • Designed two thermal storage schemes: cascade and partial thermal storage • Cascade and partial thermal storage reduce room thermal comfort at full heating. • Low-temperature PCM is difficult to solidify in cascade thermal storage. • Partial thermal storage greatly improves room energy efficiency and economy. • Different heating methods are suitable for different thermal storage schemes.