This paper describes modelling and simulation of a space with radiant cooling ceiling (CC). The computer model represents a test chamber, which is located in a laboratory of the Department of Environmental Engineering in Prague. The simulation results were obtained with the ESP-r software. These results will be used for comparison with experimental data. The main goal is to determine conditions of thermal comfort of occupants in a room with cooling ceiling and various heat gains. The paper also presents the influence of the room height on thermal comfort.