The purpose of this paper is to apply reliable boundary conditions based on previous studies in order to analyze the airflow pattern caused by the stack effect in high-rise hospitals. An analysis was carried out on the vertical airborne transmission of viruses according to the location of the infected patients. The horizontal airborne transmission based on the characteristics of the supply air diffuser and return air grille were also analyzed by using the multi-zone airflow simulation and CFD simulation. In addition, this paper explored solutions to prevent the spread of airborne pathogenic bacteria by analyzing various alternatives of HVAC systems and basic data on ventilation system planning for high-rise hospitals.