In this study, the heat transfer enhancement and pressure drop values of seven different fin angles with plain fin-tube heat exchangers were investigated. The numerical simulation of the fin-tube heat exchanger was performed by using a three dimensional (3-D) numerical computation technique. Therefore, a CFD computer code, the FLUENT was used to solve the equation for the heat transfer and pressure drop analyses in the fin-tube heat exchanger. The model drawing was created and meshed by using GAMBIT software. The heat transfer and pressure drop values of the vertical fin angle (theta = theta degrees) were provided to compare with variable inclined fin angles (theta = 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees). The heat transfer values were normalized to compare all cases. For inclined fin angle theta = 30 degrees, which is the optimum angle, the maximum heat transfer enhancement per segment was obtained 1.42 W (the normalized value 105.24%), the maximum loss power associated with pressure drop per segment was only 0.54 mW. (C) 2007 Elsevier Ltd. All rights reserved.