Although displacement ventilation combined with cooled ceiling provides potentials for energy savings, reheat is still required to satisfy the supply air temperature requirement. This leads to unnecessary energy waste. Two new systems have been developed: one with sensible heat recovery for reheating and the other with electrostatic dehumidification. Results from hourly simulations of these two systems serving a typical office building in Hong Kong indicate that the first system can significantly improve the energy performance of air handling systems. Electrostatic dehumidification is competitive with conventional dehumidification technologies, and needs further research for accurate determining and great enhancing its energy performance.