The cooling performance of ceiling radiant cooling panels (CRCP) is different from those measured in the laboratory under standard conditions. This paper explores the actual cooling performance of CRCP without mechanical ventilation. Experiments were conducted in an office room under different working conditions and a heat transfer model was established based on the experimental results. According to the actual performance of CRCP, the influencing factors were determined and correction coefficients were proposed. Comparing with the manufacture's data, cooling capacity of panels can be enhanced by 17.1% with characteristic temperature difference of 8 degrees C; temperatures of inner surfaces in the room and air velocity around the panel surface are the two main influencing factors, in which air velocity accounts for nearly 75% of the enhancement; the correction coefficients varied from 1.02 to 1.26 under different conditions. (C) 2012 Elsevier B.V. All rights reserved.