The work deals with thermal and hydraulic modeling of fin-and-tube cross-flow heat exchangers with a non-uniform flow of media. A maldistribution of media flow is not considered in the standard thermodynamic analysis, and the results of such analysis may be too optimistic. The authors applied two modeling methods to include the information about a non-uniform flow of media through the heat exchangers. The finite difference method and the numerical approach are applied in the first and in the second stage of the analysis, respectively. The general assumption is that the real device can be divided into repetitive elements, thus allowing to consider the media flow non-uniformity. The two methods are used for simulations of selected experiments carried out for a single-row fin-and-tube cross-flow heat exchanger. A traditional computational analysis is also performed and a comparison of the results is made. The results confirmed the applicability of the proposed methods.