The aim of this study is to examine the influence of several porous layer configurations on the hydrodynamics and thermal performance in a channel or microchannel. Various configurations and different number of the porous layers across the channel are analyzed while keeping the total amount of the utilized porous material fixed. Influence of various effective variables including the number of porous layers, permeability, configuration and thermal conductivity ratio on heat transfer, pressure drop and overall performance are investigated. It is observed that different number of porous layers lead to different overall performances in the microchannel based on the thermal conductivity ratio, permeability and the layer configuration. It is shown that when the matrix and fluid thermal conductivities are close, increasing the number of porous layers lead to better performances when the layers are concentrated at the center of the channel, while at higher thermal conductivity ratios, two highly permeable porous layers located at the walls provides the best performance. Finally, it is shown that the usage of more than four layers does not provide any additional beneficial effect. (C) 2018 Elsevier Ltd. All rights reserved.