Enhancing thermal comfort and energy-saving potential of the buildings with multiple-layered phase change material

The increasing population, rising living standards, and growing use of indoor spaces have significantly increased energy demand in the construction sector. This situation highlights the need for innovative building envelope design to reduce energy consumption and promote environmental sustainability. In this context, phase change materials (PCM), known for their high thermal energy storage capacity, emerge as an environmentally friendly solution. Key factors affecting the thermal comfort and energy consumption of buildings include the type, thickness, melting temperature, and number of layers of PCM. Although most of the research is focused on the use of single-layered PCM in exterior wall design, research on multiple-layered PCMs is quite scarce. Thus, the current study aims to assess the use of multiple-layered PCM in the exterior wall design of an educational building located in different climate zones of Türkiye. Simulations were conducted to evaluate the impact ofmultiple-layered PCM and PCM-thermal insulation (TI) combinations on thermal comfort, energy-savings, and construction costs during both summer and winter periods. Istanbul and Erzurum were chosen to represent temperate-humid and cold climates, respectively. Simulation results revealed that wall sections combining PCM and TI had higher thermal performance and energy-savings compared to those with only PCM. Multiple-layered PCM provided better thermal comfort with lower energy requirements for summer and winter periods, compared to single-layered PCM. Wall sections with multiple-layered PCM (3 PCM layers, each 30 mm) and TI (30 mm) could achieve energy savings of up to 3.93% in heating energy consumption and 2.77% in cooling energy consumption, compared to single-layered PCM.