Design and optimization of zero energy building

In this study, thermal performance analysis and economic optimization of a 120 m² detached building with phase change material (PCM) integrated Trombe wall on the south wall is carried out to reduce the total annual heating and cooling demand in line with the zero energy building (ZEB) target under Turkish conditions. For this purpose, a ground source heat pump (GSHP) is used for both heating and cooling requirements. Three different building configurations for three different climatic zones of Turkey are investigated in TRNSYS. Among these configurations, the PCM-integrated Trombe wall building (TWB) has the lowest annual energy consumption compared to the standard building (SB). A grid-connected photovoltaic-thermal (PV/T) system and a wind turbine (WT) cover the entire annual electricity consumption of the building, resulting in a net zero energy building (ZEB). The particle swarm optimization (PSO) algorithm in GenOpt software is used to economically optimize the size of the PV/T and WT system to meet the annual energy and domestic hot water (DHW) requirements of the building. Accordingly, the annual electricity energy reduction rate of PCM-integrated TWB compared to SB is 11.9%, 18%, and 34.3% for Bursa, Ankara, and Erzurum provinces for natural convection, while it is 9.8%, 12.8%, and 33.3% for forced convection, respectively. The hourly levelized total capital investment cost ratios of PV/T and WT systems are 0.35 $/h, 0.42 $/h, and 0.40 $/h for the natural convection PCM-integrated TWB in Bursa, Ankara, and Erzurum, while they are 0.35 $/h, 0.46 $/h, and 0.39 $/h for the forced convection. Levelized Cost of Energy (LCOE) is calculated as 0.05 $/kWh, 0.07 $/kWh and 0.03 $/kWh for the natural convection PCM-integrated TWB and 0.06 $/kWh, 0.1 $/kWh and 0.03 $/kWh for forced convection for Bursa, Ankara and Erzurum respectively. Payback period (PBP) is calculated as 11.6 years, 13.7 years and 8.4 years for the natural convection PCM-integrated TWB and 13.02 years, 16.48 years and 8.64 years for forced convection for Bursa, Ankara and Erzurum respectively. Except for a few days throughout the year, the PMV index in both forced and natural convection PCM-integrated TWB remains between -0.5 and 0.5, while the PPD index remains below 10%, indicating acceptable thermal comfort conditions in all cities.