Enhancing energy efficiency of buildings located in the Mediterranean area using Phase Change Materials (PCMs) integrated into mortar formulations

Phase Change Materials (PCMs) in building materials can significantly reduce energy consumption in heating and cooling systems. PCMs absorb, store, and release thermal energy by transitioning between solid and liquid states based on external temperatures, helping to regulate indoor temperatures and lower energy use. This study evaluates the thermal performance of various mortar compositions containing PCMs made from hydraulic lime and cement. The PCMs were developed using the "form-stable" method, incorporating a porous matrix of Lecce Stone (LS), known for its high porosity, and sourced from processing waste, supporting sustainability principles. The selected PCMs were Polyethylene Glycol (PEG) with molecular weights of 800 and 1000 g/mol, suitable for Mediterranean climate temperatures. The temperatures that characterize this geographic area were simulated in a climatic chamber to assess the thermal behavior of the mortars containing the PCMs across all four seasons. The results showed that mortars with composite form-stable PCMs effectively mitigated indoor temperature fluctuations, reducing the need for heating and cooling. Additionally, energy savings calculations demonstrated significant reductions in heating and cooling costs, underscoring the potential of the PCMs to enhance building energy efficiency.