The analytical techniques involved in the calculation of the time required to cool agitated and unagitated batches are well known to the chemical process industry. Early work in the field of heating and cooling times was done by Bowman, et al, Fisher, and Chaddock and Sanders. A recent paper by Antonetti, et al. applied the E-NTU method to batch cooling problems. The calculation of cooling times involving direct expansion equipment, however, is often performed by resorting to approximations based on average conditions during the "pull-down" period and without consideration to the degree of mixing of the batch being cooled. This paper examines the influence of a varying refrigerant suction temperature on the cooling times of two extreme cases of agitated and unagitated batches.