The cooling energy in different rooms can be different particularly if there are rooms that are very seldom occupied. With uncertainties in the cost and availability of local and global energy nowadays, it is imperative that a study on the actual cooling load of a building system be performed to reduce the energy consumption. In this paper, the effect of manipulation of the operating configuration of the cool air supply system is studied experimentally and also by computer simulation on selected occupied air-conditioned areas. The study is mainly conducted by re-configuring the damper opening and mode of control depending on the trend of occupancy throughout a typical working day for a selected zone within a campus building. The potential savings in energy as a result of the proposed strategy are estimated based on computer simulation. The results are compared with those of the experiment. The study reveals that there are significant potentials for savings in the cooling energy of the buildings. © 2012 American Institute of Physics.