An Improved Method for Determining Heat Transfer Fin Efficiencies for Dehumidifying Cooling Coils (RP-1194)

Fin efficiencies are used within cooling coil models to simplify heat and mass transfer calculations associated with the use of air-side fins. These models utilize relationships developed for dry fins (i.e., no condensation) in determining convective heat transfer and modified fin efficiencies for estimating combined heat and mass transfer. However, the fin temperature distribution is different for wet and dry fins and, therefore, the use of a dry fin efficiency relationship for convective heat transfer is not strictly correct under wet conditions. This paper develops a correction factor for existing fin efficiency relationships that allows a better estimate of convective heat transfer fin efficiencies under wet conditions. The improved method is validated using results obtained from a two-dimensional numerical analysis and experiments performed on an eight-row cooling coil.