Analysis of a one-dimensional conduction heat transfer model to study the performance of a cooling and dehumidifying fin assembly has been carried out. The conventional method was extended by incorporating the ratio of sensible to total heat transfer into the analysis of fin assemblies during dehumidification. The use of this ratio, which is widely used in psychrometric calculations, led to the identification of the correct qualitative importance of the parameters influencing the fin assembly performance during sensible heat transfer and sensible and latent heat transfer. The effects of variations in the relative humidity (50-70%). dry bulb temperature (25-35 degrees C) and cold fluid temperature (0-10 degrees C) on the temperature distribution and also on the augmentation factor, which are important during the design stage of finned tube dehumidifiers, are investigated and compared with those under dry conditions. It was concluded that a significant decrease in augmentation factor occurs as the amount of dehumidification increases.