Abstract: In Australia 70% of end-use energy consumption in non-residential buildings is spent on heating, ventilating and air conditioning (HVAC) system. This is due to very high ambient temperature and humidity in the afternoon which persists for a long period in the summer season. Consequently, buildings peak energy consumption contributes significantly in a short duration of time. Shifting the electrical loads to off-peak periods is achieved by introducing peak demand charge and time of rate tariff as incentive control on the demand-side management (DSM) by using active thermal energy storage technology. In the HVAC industry cool storage on a large scale used to provide a cool reservoir for use in peak periods, is the most preferred DSM technology for shifting cooling electrical demand from peak hour to off-peak hour. It is also seen that efficiencies of the air cooled chillers are increased if they run overnight. In this study, air cooled chillers load for an institutional building is evaluated using the simulation software called Design Builder which is based on Energy Plus simulation engine. Load profiles of existing systems are simulated first and then verified by on-site measured data. Under the Australian electricity tariff rates, the results show that the full ice storage can save up to 63% of the electricity cost required for cooling when compared with the conventional system. It is also found that using full storage option can reduce the total energy consumption upto 5% for the selected building.