Current ice-storage technology can be separated into two-distinct categories - direct ice storage and indirect ice storage. Direct ice storage is characterised by production of ice directly on the evaporator and includes the ice-on-coil system and ice harvester. In such systems, the presence of ice on the evaporator has a direct influence on evaporator performance, and the ice-storage unit must be modelled as a component of the refrigeration cycle. Indirect ice storage is characterised by the production of ice at a remote location and includes ice container systems and ice-on-coil inside-melt systems. In such systems, a brine solution is circulated between a chiller and the ice storage unit. As a result, the chiller and the ice-storage unit can each be modelled separately. The indirect ice-storage unit can be thought of as a heat exchanger, and the model developed for these systems follows logically from a standard heat exchanger formulation. Describes the development of models for both direct and indirect ice-storage systems and discusses their salient features as applied to energy analysis calculations. The models described have been implemented in the Building Loads Analysis and System Thermodynamics (BLAST) energy analysis program. Relevant control strategies used by the ice-storage models are presented. An example of matching the model parameters to the manufacturers' performance data is discussed.KEYWORDS: energy storage, ice storage, ice makers, evaporators, performance, calculating, refrigeration, computer programs, chillers, heat exchangers, direct cooling, indirect cooling, compressors, condensers.