Indoor swimming pools are facilities in which a ventilation system has a vital impact on the proper operation of the building, as well as the users' comfort, operating costs and the safety of the structure. The major problem in ensuring appropriate thermal-moisture conditions is the removal of moisture that is mainly gained from the surface of the water in the pool's basin. The aim of this paper was to experimentally identify the physical phenomena occurring in the actual indoor swimming pool and to evaluate whether the numerical model of the facility, developed with the use of Ansys CFX 14.5 software, correctly mapped these phenomena and how it should be improved in this field. Results of the experimental research of the air variables, carried out in various periods of the year, were used to identify the changes in the thermal-moisture conditions and to prepare boundary conditions for the numerical calculations, as well as to validate these simulations experimentally. The numerical model was improved with the use of the authors' own method of modelling moisture emission from the surface of the water. It was based on the implementation of literature formulas for calculating the value of this parameter in the software. The validation encompassed the indoor airflow pattern and the distribution of the air flow variables above the surface of the water and around the pool's basin. The improved numerical model was able to reproduce the actual conditions in the indoor swimming pool with good concurrence of the experimental and predicted values.
