Enhancing heating efficiency in electric radiant flooring systems with low-cost shape-stabilized paraffin wax composites: An experimental study

In regions with traditional biomass as the main energy source, buildings can consume up to 80 % of total energy. Utilizing phase change materials (PCM) in thermal energy storage (TES) systems is demonstrating to be a practical approach for economically improving energy efficiency in buildings. This study assessed the feasibility of applying low-cost PCM to an electric radiant flooring heating system (ERFHS) in three steps. The first step involved analyzing the thermal performance of n-eicosane, n-docosane, and paraffin wax, showing variations in the latent heat capacities and cumulative specific heat values. The second step involved developing a shape-stabilized composite PCM (AC-SSCPCM) with activated carbon (AC) to enhance heat transfer performance. The AC-SSCPCM was manufactured by vacuum impregnating paraffin wax with AC at a 1:1 mass ratio. The AC-SSCPCM exhibited a 50 % increase in latent heat compared to pure paraffin wax, with improved heat transfer in the dynamic analysis. Third, the compatibility and heat transfer of the octa-AC-SSCPCMs mixed with n-octadecane were evaluated. This study highlights the time-lag effects in PCM-applied ERFHSs and demonstrates the influence of the phase change temperature and latent heat capacity. The mixed-AC-SSCPCM and octa-AC-SSCPCM exhibited enhanced heat transfer performance, indicating their potential applications in energy-efficient systems.