Performance of the staggered and inline tube bundles with three rows covered by a porous layer has been numerically studied from the viewpoint of the first and second law of thermodynamics. The results indicate that wrapping tubes with a porous layer bring about Nu number augmentation as well as pressure drop increment in comparison with the bare tube banks for both inline and staggered configurations and for both flat and circular tube shapes. In addition, bundles with porous layer wrapped flat tubes have a higher thermal performance and lower entropy generation rate than those of porous layer wrapped circular tubes, especially for the staggered configuration. The investigation on heat transfer, pressure drop and entropy generation rate is performed for different pitch spacings as well as different thicknesses of porous layer in order to find the optimal designs. The porous layer wrapped banks with flattened tubes show a great potential for application in heat exchangers.