A new method was proposed for enhancing heat transfer between water and refrigerant and making bulk water freezing uniformly by installing three plates with small holes through the coils in the storage tank. This new construction design was applied to a 3HP ice-storage air-conditioning unit using R410A. Experimental investigations were conducted to inspect the performance, including the measurements of refrigerant mass flow rate, evaporating temperature, stored thermal energy, power consumption, ice fraction, Efficient energy ratio (EER) during 10 hours freezing process. The prototype of ice-storage air conditioner reached a mean EER of 2.45, stored thermal energy 162.1MJ and ice packing factor 61%, tested based on the Japanese Standard JISB 8625.