A unique design arrangement for longitudinal and pin fins involving surface dehumidification is proposed for improving the fin's heat transfer enhancement under transient operating condition. The new design arrangement involves dual primary fin surfaces. For the present analysis, the assessment of Fourier and non-Fourier effects is made, and a closed form solution methodology involving separation of variables is adopted to evaluate the fin performance. The proposed closed form methodology for the non-Fourier heat transfer effect in the wet fin is well-validated with the corresponding numerical solution obtained under finite differencing framework. Furthermore, for a dry surface condition, the validation of the present non-Fourier model is done with the pertinent results available in the literature. The Fourier and the non-Fourier heat transfer effects are investigated with various design variables of the wet fin and surface conditions. It is highlighted that the effect of air dehumidification in fins promotes waviness in the temperature distribution. The efficiency is determined to be higher in the case of the longitudinal fin than that of the pin fin, whereas, an opposite behavior is revealed in terms of the fin effectiveness. Higher fin efficiency is observed at lower values of the Fourier number and higher values of the Vernote number. It is apparent from the present study that the proposed new fin design considerably enhances the rate of heat transfer as compared to the conventionally used design. Additionally, the proposed design results in a compact geometry that in turn provides additional mechanical strength resulting in the savings of space utilization and costs related to fin manufacturing. (C) 2018 Elsevier Ltd. All rights reserved.