Evaluation of thermal properties of phase change material-integrated artificial stone according to biochar loading content

Biochar is biomass that has undergone pyrolysis and contains many pores; therefore, it can effectively be used as a building material. This experiment aims to improve the thermal performance of artificial stone finishes used as interior veneers. A phase change material (PCM) with a high latent heat performance and biochar, an eco-friendly material, were used in the experiment. n-Octadecane was incorporated into lightweight aggregates; spruce tree, rise husk, and miscanthus straw biochars were utilized. The strength performance of specimens using biochar was found to be slightly degraded when 6% biochar was incorporated, and biochar use within 4% was found to yield similar or higher strength results. Moreover, the thermal conductivity decreased as the amount of biochar in the mixture increased; these thermal conductivity characteristics depended on the pore characteristics of the biochar type. It was demonstrated that the use of 6% biochar reduced the peak temperature of the specimen by 4–5 °C. Using biochar that reuses waste can have environmental benefits; biochar can facilitate efficient use of thermal energy and indoor temperature control when used in combination with PCM.