This study presents the airside performance of fin-and-tube heat exchangers with plain fin configurations. A total of 18 samples were tested. The effect of the number of tube rows, fin pitch and tube diameter on the thermal-hydraulic characteristics was examined. Depending on the number of tube rows, it was found that the heat transfer characteristics were strongly related to the fin pitch. For N = 1 or 2, the heat transfer performance increased with decrease of fin pitch. For N greater than or equal to 4 and Re-Dc > 2000, the effect of fin pitch on heat transfer performance was negligible. For the same fin pitch, the effect of the number of tube rows on the friction performance was very small. The effect of tube diameter on heat transfer performance is related to fin pitch as well. Pressure drops for D-c = 10.23 mm exceed those of D-c = 8.51 mm by approximately 10-15%.