SAPUNOV A. Evaluation of Energy Efficiency of a Preschool Educational Building under Thermal Comfort Conditions

The first chapter of the dissertation is devoted to the analysis of theoretical aspects of building energy efficiency. The main principles of energy efficiency are highlighted, such as thermal insulation, energy-saving materials, heating and cooling systems, lighting, the use of renewable sources, and the impact of user behavior on energy consumption. The requirements for new construction and building reconstruction according to Ukrainian energy efficiency legislation are considered. Special attention is paid to the use of computer modeling to assess energy consumption and reduce carbon emissions. In Ukraine, tools like EnergyPlus, eQUEST, TRNSYS, DesignBuilder, IDA ICE, and DIALux are gaining popularity. Implementing these technologies facilitates the development and modernization of building projects to enhance energy efficiency. Modern research in the field of energy efficiency and comfort in buildings is highlighted. Various approaches to ensuring energy efficiency and comfort are considered, including the use of advanced programs for modeling the energy characteristics of buildings. Special attention is paid to the needs of children and the elderly in creating optimal living conditions. The second chapter of the dissertation describes the object of the study — a preschool educational institution in Kyiv. The building's settings are examined in detail using the DesignBuilder software environment, which allows for the assessment of the building's thermal characteristics and the risks of moisture condensation. For dynamic modeling, climate data from the IWEC weather file for Kyiv are used. The program enables the assessment of energy needs and the impact of weather conditions on comfort. Using DesignBuilder helps analyze the building's energy efficiency and thermal comfort, allowing for the development of recommendations to improve efficiency standards. The third chapter examines the impact of thermal modernization on reducing energy consumption. Two scenarios are compared: the current state of the building and a modernized version with increased insulation according to Swedish standards. Modernization of the building envelope significantly reduces heating energy costs. It is established that intermittent heating, combined with increased thermal resistance of structures, leads to further reductions in energy consumption. The impact of changing the building's functional purpose on its energy needs is considered. Changing the building's purpose from a kindergarten to an office significantly reduces energy costs. The importance of the building's geographical orientation and solar gains, which improve thermal comfort and reduce additional heating, is emphasized. A comprehensive approach to modernization includes insulation, efficient use of solar energy, and rational space planning. An analysis of radiation temperature and geographical orientation of the premises shows that improving insulation characteristics reduces energy consumption and positively affects thermal comfort. This is especially true for south-facing rooms, where additional heat gains through windows enhance thermal perception. The results show the possibility of lowering indoor temperature without losing comfort, further promoting energy savings. The fourth chapter studies the effect of improving building energy efficiency during the summer. The study of energy efficiency measures in the summer highlights the importance of integrating split cooling and heating systems for preschools. The analysis of modeling results shows that improving the thermal protection of building envelopes reduces energy consumption for cooling and heating, ensuring the necessary level of thermal comfort. Special attention is paid to the summer months, when intense solar radiation can lead to overheating and increased cooling costs. Passive methods, such as window shading, are discussed to reduce energy consumption. Using DesignBuilder, energy needs for cooling and lighting costs for shaded and non-shaded options are assessed. Static shading is the most effective, reducing cooling energy consumption by 74.98 kWh for a representative room, although it increases lighting energy consumption by 4.63 kWh. Installing roller blinds is less effective due to increased lighting costs and slight reduction in cooling energy needs.