In the present study, heat transfer and pressure drop characteristics of aluminum porous fins mounted on a surface in a rectangular channel were studied. Nusselt number, heat transfer enhancement ratio and heat transfer performance for three gap heights over pore fins (C/H = 0, 0.5 and 1) as well as three longitudinal fin pitches (S-x = 116, 126 and 136 mm) were investigated for the range of 5000 < Re < 35000. It was found that use of larger gap height over fins has a significant effect on the Nusselt number while the longitudinal fin pitch has a negligible influence on it. The highest heat enhancement ratio (Nu*) was obtained as 470-660% for the case of C/H = 0 and S-x = 136 mm. Furthermore, the highest heat transfer performance (eta) was in the range of 1.7-2.6 for the case of C/H = 1 and S-x = 136 mm. The highest heat enhancement ratio (Nu*) was obtained for C/H = 0 and S-x =136 mm while the highest heat transfer performance (eta) was obtained for C/H = 1 and S-x = 136 mm. In conclusion, the heat transfer performances (eta) studied are advantageous for all fin and channel arrangements, since heat transfer performances (eta) for all present tests are higher than unity. (C) 2017 Elsevier Ltd. All rights reserved.