A numerical study on the heat transfer enhancement and pressure drop has been performed. Results are presented as plots of heat flux, pressure drop, j-factor and f-factor. CFD analysis has been carried out on conventional fin type as a reference case to derive the parameters for heat transfer enhancement. The basic concept for the heat transfer enhancement has been focused on the hybrid type of slit and louver combined. Out of the studied cases, best case has been selected for further DOE study with parameter of slit shape. CFD results show agreement with experimental data with 7.5% of error. Using the result of the study, the fin pitch has been increased from 1.5mm to 1.7mm resulting in cost saving in heat exchanger for same performance.