Yizhe Xu

In light of global climate change and China’s commitment to carbon neutrality by 2060, this study explores energy-saving and decarbonization design optimization for educational buildings, with a specific focus on a high school canteen in Nanjing. Through a comparative analysis of optimal energy-saving and lifecycle decarbonization retrofit schemes, the study aims to identify the performance differences and provide practical guidance for retrofitting educational buildings. The optimization process involves two separate single-objective optimizations: one aimed at minimizing annual total primary energy consumption (TES) and the other at minimizing lifecycle carbon emissions (E). Energy performance is simulated using EnergyPlus 23.1.0, while the Strengthened Elitist Genetic Algorithm (SEGA) is applied to optimize design variables such as insulation materials, window types, window-to-wall ratios (WWRs), and photovoltaic (PV) system configurations. The results reveal that the optimal energy-saving scheme achieves zero net energy consumption annually, generating a surplus of 20,625.2 kWh (15.05 kWh/m²). Conversely, the optimal decarbonization scheme achieves zero lifecycle carbon emissions, contributing a carbon reduction of 386,926.4 kg, albeit with a 28.83% higher lifecycle TES compared to the energy-saving scheme. This study underscores the distinctions between energy-saving and decarbonization retrofits and offers valuable insights for sustainable retrofitting of educational buildings in China.

Kindergartens play a crucial role in nurturing the physical, cognitive, and social development of children. Hence, designing kindergarten buildings requires the consideration of the unique requirements and behavior of children. Considering the rapid urbanization of China and its commitment to achieving the 3060 carbon goal, in this study, we examine the retrofitting of kindergarten buildings in China and propose a retrofit optimization method for kindergarten buildings that considers thermal comfort, daylighting, and life-cycle carbon emissions. Through this method, information on the thermal and daylighting comfort of occupants, weather data, occupant scheduling, and envelope and energy system of the kindergarten building to be retrofitted can be obtained through various approaches, such as video playback, field investigation, literature research, and consult drawings. On this basis, optimization variables are selected, and a physical model is established to guide the retrofit process. Afterward, a rapid comprehensive optimization framework based on parallel computing is adopted to obtain the comprehensive optimal design scheme for the building to be retrofitted. The proposed method is applied to a kindergarten building retrofit case in Nanjing, China, and the results show that the optimal comprehensive scheme results in a reduction in carbon emissions of 34,158.3 kg, an increase in the thermal comfort period of 2.7%, and an improvement in daylighting comfort of 79.7% over the benchmark scheme. The significance of this study extends beyond its potential for widespread application in kindergarten building retrofits. It contributes to advancing sustainable building design and environmental stewardship, creating healthier and more comfortable learning environments for children while mitigating the environmental impact of buildings. Moreover, it emphasizes the importance of considering children’s unique needs and behaviors in building design, ultimately leading to better outcomes for their overall development.