The ability to predict the drying behavior of thin films and coatings is of great importance to the coating industry and governs the economical production of various polymeric products. In conventional drying processes, a continuous layer of polymer solution is deposited onto a substrate, which is dried in an oven with forced air convection. Recently, a gap dryer was developed that eliminates the need for forced gas flow and provides direct solvent recovery. A model that incorporates simultaneous heat and mass transfer in the bulk polymer and gas phases and jump conditions across the interface is utilized to describe the drying of a binary polymer-solvent system in a gap dryer: Solvent self-diffusion in the polymer phase is described by free-volume theory, and the Flory-Huggins theory is used to describe polymer-solvent thermodynamics. Simulations indicate the possibility of condensation in the gas phase that carl decrease both drying efficiency and coating quality. A method to resolve this problem is proposed, as well as a comparison between the performance of a gap dryer and a conventional convection-oven dryer.