This study investigates the dynamics of air exchange rates and carbon dioxide (CO2) concentrations in indoor environments, particularly focusing on residential and educational buildings. Utilizing both experimental and simulation modeling methods at Igor Sikorsky Kyiv Polytechnic Institute and standard residential apartments, the research analyses factors influencing air exchange, such as wind direction, temperature, and stack effects. Key findings highlight the significant impact of human occupancy on CO2 levels and the necessity of adequate ventilation to maintain optimal air quality and energy efficiency. The study further demonstrates the energy implications of different air exchange rates through dynamic modeling with DesignBuilder and EnergyPlus software, revealing potential energy savings when natural air exchange rates are appropriately managed. The outcomes emphasize the importance of monitoring ventilation and CO2 concentrations to improve indoor microclimate conditions and inform energy-efficient building design and standards.