This paper presents the results of an experimental analysis of the radiant ceiling systems in both heating and cooling modes coupled to its environment (fenestration, walls, internal loads and ventilation system). The main objective of this study is to present the results of the experimental analysis and measurement methods and its discussion. Two test chambers are adapted in a way to reproduce as good as possible the characteristics of the real offices located in Brussels (Belgium). Forty-six tests are performed to observe the influence of parameters such as the mass flow rate, supply water temperature, fenestration and ventilation system effects and thermal load distribution. Laboratory test results show that the influence of surfaces temperatures inside the room, especially the facade, is considerable. Therefore, the system must be evaluated together with its designed environment and not as separate HVAC equipment. (C) 2010 Elsevier Ltd. All rights reserved.