The mass transfer coefficient from the product to condenser, Kcc, is one of the key values in this model. It reflects the major characteristics of a freeze-drying system. For the system modeled here, the value of Kcc is sufficiently large that the mass transfer velocity of sublimated moisture is limited by the resistance in the dried cake. Thus, the sublimation process can be tuned to improve the sublimation rate and/or mass transfer velocity, for example, by increasing product temperature, freezing to produce large ice crystals, etc. However, in systems where the value of Kcc is smaller, the mass transfer velocity of sublimated moisture may be limited by the resistance in the drying system. This could be particularly significant in cases where a lot of product is loaded into the dryer, and an excessive amount of moisture is produced by drying. Determining the value of Kcc is thus important for planning a drying scheme, and is useful for designing scale-up. An optimal drying condition obtained for a laboratory-scale (or pilot-scale) freeze-dryer will not be optimal for full-scale dryer. Knowledge of the Kcc value of each dryer allows the conditions that realize the desired drying kinetics to be explored. As noted above, there is much still to be investigated to understand the contributions to this mass transfer coefficient in detail. Comparison of the freeze-drying kinetics of dryers that have different Kcc values would be an interesting study.