Thermal Energy Storage Performance of EPCM-Impregnated Moss Biomass Placed in OKAL Chipboard for Use in Building Envelopes and Interior Space Separation

This study develops an innovative thermal energy storage approach for lightweight building systems by using eutectic phase change material (EPCM)-impregnated moss biomass (Cp/EPCM) in the internal voids of OKAL chipboard (OKS-Cp/EPCM). A high latent heat storage (LHS) capacity of 121.4 J/g was achieved with a 72% EPCM loading. Furthermore, the thermal conductivity of the OKS-Cp/EPCM decreased from 0.15074 W/m·K to 0.109 W/m·K. Thermal imaging results showed that the OKS-Cp/EPCM improved thermal comfort by reducing the surface temperature by approximately 10.5 °C in hot environments and providing an approximately 1 °C higher surface temperature in cold environments. However, TGA analyses revealed that the thermal resistance of the composite was limited. Relative humidity results also indicated that Cp/EPCM positively contributed to the moisture regulation performance of the board. Based on these results, OKS-Cp/EPCM offers a promising solution for the development of energy-efficient and thermally comfortable lightweight building elements.