In general, one of the most important factors in assuring people’s thermal comfort in residential areas is air quality. In residential buildings, poor air quality can cause a number of health problems, including headaches, respiratory diseases, and allergic reactions to specific bacteria and fungus. The ventilation of spaces, which includes the process of supplying fresh outdoor air into the interior and, on the other hand, expelling contaminated indoor air to the outside through the building’s envelope, is directly related to air quality. The amount of external, fresh air that enters the space and the associated ventilation effectiveness are critical components of space ventilation. Our post focuses on the preparation of experimental measurements of the indoor environment in residential spaces, with an emphasis on air quality parameters, thermal comfort, and ventilation system efficiency. By using tracer gases and precise sensors, measurements will be taken of CO₂ concentrations, the age of air, and indoor environment parameters at various heights. The results of these measurements will then be validated through CFD (Computational Fluid Dynamics) simulations to model air flow and heat distribution. The combination of experimental data and CFD analysis provides a comprehensive understanding of the indoor environment and allows for the optimization of ventilation systems to improve the comfort and health of residents. The paper also deals with the issue of thermal bridges at the point of installation of the ventilation unit and noise transmission from the exterior through the ventilation unit.