Eskinder Desta Shumuye, Cheikh Makhfouss Fame, Saeid Mehrpay, Muhammad Hassan Riaz, Łukasz Sadowski, Tamon Ueda, Biqin Dong, Guohao Fang
As heating and cooling demands in buildings rise, energy consumption has increased, with HVAC systems accounting for 38% of total building energy use in 2020. Phase change materials (PCMs) store and release thermal energy during phase transitions, improving energy efficiency and thermal comfort. They are classified as organic (paraffin wax, polyethylene glycol), inorganic (salt hydrates, metallic compounds), and eutectic mixtures (fatty acid esters with fatty alcohols). Key thermal properties, including melting temperature, latent heat, and thermal conductivity, determine their performance. Despite the extensive research on PCM types and applications, research gaps remain regarding integration with waste-processed building materials and the role of advanced encapsulation techniques in improving thermal performance, durability, and practical applicability. This review systemically addresses these gaps by examining thermal properties, material characterization, energy-saving potential, and implementation strategies for sustainable construction.