This paper presents a comprehensive design model of the single effect mechanical vapor compression process. Previous literature models focused on determination of the heat transfer area and compressor power consumption. Several new design features included in this study are the evaporator dimensions, demister dimensions,dimensions of the non-condensable gases venting orifice, and capacity of the vacuum system. The model equations include fundamental mass and energy equations; power consumption of the vapor compressor; and a well tested set of correlations for calculations of the physical properties of the vapor and liquid streams, heat transfer coefficients, and thermodynamic losses. Dependence of system variables on temperature and salinity makes the system equations nonlinear and requires an iterative solution. System performance is discussed as a function of the product flow rate, brine boiling temperature, temperature difference of the saturated boiling brine and compressed vapor, and length of the evaporator tube. Comparison of the design results against available field data shows good agreement for the predictions of specific power consumption and specific heat transfer area.