Relevance of the topic. Rational ventilation, that is, properly organized air exchange in buildings is one of the most important conditions for ensuring an adequate level of air quality. According to Erisman, “air is the most common and necessary environment and of all those with which a person comes into contact and makes one of his first sanitary and aesthetic needs, and a change in his physical or chemical properties easily breaks that the physiological state of the body, which we call health . ” Particularly relevant is the problem of air exchange in the premises of hospitals, where it is the most effective measure to prevent airborne nosocomial infections.