A thermal energy-storage air-conditioning (TESAC) system for a 600-bed hospital was simulated for the purpose of determining operational strategies for seasonal weather changes. An analytical design method termed EWMA has been developed to predict the cooling load on the following day with a deviation of <8% from experimental results. System performance was successfully validated in a full-scale experiment for which the power demand was limited to 50% of original value, resulting in 25% savings of operational cost.