This study is to evaluate energy saving potential of ceiling mounted personalized ventilation (PV) system in conjunction with background mixing ventilation compared with mixing ventilation system alone and with mixing ventilation system when occupants are provided with individually controlled desk fans for generating additional air movement at each desk. Control strategy applied includes different number of personalized ventilation air terminal devices used and different PV airflow rates supplied. Energy calculation is based on design conditions in Singapore, representing a hot and humid climate. The results reveal that increasing room temperature can save cooling energy when the combination of PV with ceiling mounted personalized ventilation nozzles and background mixing ventilation is used. In this case the energy for transport of air increases but the total energy decreases, i.e. energy can be saved due to elevated room temperature. Comparing with mixing ventilation plus desk fans, ceiling mounted personalized ventilation cannot only realize better cooling effect but also decrease the total energy consumption. (C) 2010 Elsevier B.V. All rights reserved.