This work proposes an optimization model for heat-exchanger network synthesis that includes a heat-exchanger design model. This model takes into account several detailed design variables: number of tubes, number of tube passes, internal and external tube diameters, tube arrangement pattern, number of baffles, head type, and fluid allocation (i.e., to the shell or tubes). The network superstructure with individual heat-exchanger designs is solved using the logic-based outer approximation method (Turkay, M.; Grossmann, I. E. Comput. Chem. Eng. 1996, 20, 959-978). An interesting feature of the model is that it contains disjunctions for topology selection, which in turn has disjunctions for the heat-exchanger design. The proposed model determines the heat-exchanger network that minimizes the total annualized cost accounting for area, pumping, and utility expenses. Examples are presented to illustrate this method.