In the present study, an air conditioning system with a storage tank was constructed and tested. Along the 24 hrs, eight tank-charge cycles were performed to evaluate the effect of variation local ambient temperature on the system performance. A significant variation in the values of COP due to variation in local ambient temperature in Sohag city was recorded. There are two modes of chilled water storage, full-storage and partialstorage. This study deals with partial-storage mode. In this study, a comparison has been carried out between air conditioning system without chilled water storage and that with storage. Configuration of storage tank has a significant effect on system performance. Two storage tanks with aspect ratio of 1.1 and 2.2 were tested. A COP of 1.63 was achieved for the adopted system for no-storage mode. In partial-storage mode, the COP achieved was 1.73 in case of storage tank with aspect ratio 1.1, and 1.79 with aspect ratio 2.2.