Presents a mechanistic model developed for static ice-storage tanks for both charging and discharging periods. Describes the basic heat transfer analysis and presents the characteristics of the charging and discharging periods determined from the model. An effectiveness approach is developed to describe the tank operation and is used to validate the model with manufacturer's data. The tank effectiveness is generated for both charging and discharging as a function of control variables. The effectiveness concept allows a computationally efficiency prediction of the time-dependent performance of an ice-storage tank to be made. The effectiveness approach also provides a format for correlation of experimental data and manufacturer's information.KEYWORDS: calculating, ice storage, tanks, heat flow, properties, performance, operations.Units: Dual