Abstract: Existing methods of designing heat exchangers for the condensation ofmulticomponent mixtures are of two basic kinds: equilibrium methods and non-equilibrium methods. Equilibrium methods not well-grounded in principle. The second methods are exact but they are too time consuming even in a single computation and very tedious for the design of a multichannel plate-fin exchanger. This paper is to present a total heat flux equation consisting of a heat-mass resistance factor correlated from a set of experimantal data. This is as simple as the equilibrium methods but still retain the non-equilibrium nature of the problem which signifies the condition of vapor and condensate in the condenser. The results are shown to be better than those from any approximate methods.