Three ways to improve ice storage of chiller and ice bank in series are analyzed using a system simulation program known as TSTORSP:(1)secondary pump; (2) self-regulated valve; (3) variable speed pump. It is shown that a lot of energy canbe saved by using secondary pump and self-regulated valve if constant speed pumps are used. If variable speed pump can be used, there are further more energy saved by desining proper ice storage system.