The influence of a cooled ceiling on the air quality in a displacement ventilated room is examined by means of CFD. The objective of the study is to examine how the flow field in a displacement ventilated room is influenced when a cooled ceiling removes a major part of the total heat load, and in particular to examine the effect on the contaminant distribution and the indoor air quality. The simulations show that the inclusion of a cooled ceiling has a significant impact on the flow field but only a minor influence on the personal exposure in this study.