The master thesis describes an air conditioning facility and the patterns of the process and its sub-processes during the winter and summer operating modes. A brief review of the research area associated with literature about the controlling algorithms used in the control system, the PI and PID controllers, is followed by a description of all devices and processes in it with work decription od air-conditioning facility. Based on the analysis of the physical patterns of the processes, the mathematical models of all processes were established for the air conditioning facility with concentrated parameters. a description of the existing condition of the control system, including a analysis of existing system and control algorithms in the system, during the winter and summer operating modes. The existing control system relies on the principle of cascade control. It also includes a simulation of the existing control system in the winter and summer operating modes in the MATLAB® Simulink® program. The thesis specifies the deficiencies detected on the existing control system and provides a proposal for improvement of them. This is followed by a version of an improved control system, provided as a system with coupling processes with PID controllers. The thesis also includes a simulation of the improved control system in the winter and summer operating modes in the MATLAB® Simulink® program and a discussion concerning the simulation results obtained. In addition, it is given a description and a list of the measuring and control equipment that would be incorporated into an improved control system.