Wood impregnated with multicomponent bio-based PCM for low temperature energy storage in buildings

Wood is widely used in buildings but its low thermal mass limits its energy efficiency for internal use. The thermal mass of wood can be improved by incorporation of PCMs into its porous structure, and thus can control energy intermittency inside buildings. In this study, coconut oil fatty acids mixed with linoleic acid in 4:1 (w/w), with a phase transition temperature in the range of human comfort (18-25 ºC), were integrated into thermally treated spruce. The impregnation uptake was 60% and the stability of the PCM in wood structure was evaluated by subjecting impregnated wood samples to leaching tests, and found to be 5%. Thermal characteristics of the wood/BPCM composite including phase transition temperature, enthalpy, heat capacity and thermal conductivity were investigated with DSC, T-history and heat flow meter method, and respectively found to be in the range of 22.4-25.5 °C, 39 J/g, 4 J/(g K) and 0.13 W/(m K)