Investigation of the effect of using macroencapsulated phase change material integrated into a building roof on building thermal performance and CO2 emissions

In this thesis, three residential building models with flat, inhabited attic, and uninhabited attic roof configurations were developed using DesignBuilder and simulated in EnergyPlus based on 2024 climate data for Istanbul. Commercial organic PCMs (RT18HC, RT21HC, RT24HC, RT25HC, and RT28HC) and inorganic PCMs (RPCM18C, RPCM21C, RPCM23C, RPCM25C, and RPCM29) were evaluated at different thicknesses. Various PCM-integrated roof configurations were designed, and the optimum combinations providing the highest energy savings were identified. Their thermal performance was assessed by comparing annual heating and cooling energy demands with and without PCM. The effects of PCM type, thickness, and installation location on building energy performance were investigated. Indoor thermal comfort was evaluated using hourly Predicted Mean Vote (PMV), Predicted Percentage of Dissatisfied (PPD), and annual thermal comfort hours. Annual CO₂ emission reductions were also calculated for HVAC systems using coal, natural gas, fuel oil, and electricity. Among the inhabited attic roof configurations, the highest heating energy reduction was achieved with the Type 2 roof incorporating 70 mm RT18HC, providing 31.80% energy savings, while the greatest cooling energy reduction was obtained with the Type 2 roof incorporating 60 mm RPCM21C, achieving 17.41% savings. The annual thermal comfort hours for the 70 mm RT18HC configuration were 3680, 3729, and 4078 hours for the flat, uninhabited attic, and inhabited attic roof models, respectively. Annual CO₂ emission reductions ranged from 1694.83 to 12667.30 kg CO2/year, depending on the PCM configuration and HVAC fuel type.