Bachelor´s thesis describes a design of a ventilation system for hospital facility. In this thesis first ground floor and basement designed and implemented. The system is proposed to meet hygienic, operational and functional requirements for indoor microclimate of clean spaces. The task of ventilation system is the transport of fresh air to interior, the covering of the heat looses during the winter and the covering of heat gains in the summer. The system is also designed for regulation of air humidity. Theory part of dissertation deals with clean spaces with specialization on medical facilities.