The present study proposes a new reduction method for analyzing the heat and mass transfer characteristics of wavy fin-and-tube heat exchangers under dehumidifying conditions. The analysis of the fin-and-tube heat exchangers is carried out via dividing it into many tiny segments. The proposed reduction method is applicable to the wavy fin-and-tube heat exchanger under fully wet and partially wet conditions. From the experimental results, it is found that the sensible heat transfer and mass transfer characteristics are slightly sensitive to changes in the inlet relative humidity and fin spacing. For high Reynolds numbers where partially wet condition takes place, a considerable increase of the mass transfer characteristic is encountered. The ratios of h c,o/hd,oCp,a are in the range 0.6-1.2. Correlations are proposed to describe the heat and mass transfer characteristics. These correlations can describe 99.18% of the heat transfer characteristic within 20% and 86.89% of the mass transfer characteristic within 20%. Correspondingly, 88.93% of the ratios of hc,o./h d,oCp,a are predicted by the proposed correlation within 20%.