This article deals with the performance of a randomly packed distillation column depending on the effective vapor-liquid interfacial area (a(e)) and the flood ratio (%Fl). An approach to design with respect to the derivatives of the function a(e) = f(%Fl) has been evaluated using %Fl due to the Eckert flooding model. The proposed log-basis equation for a(e) of random packings is expected to be an improvement in data fit clarifying the simultaneous impact of loading, packing geometry and system properties on the performance of a moderate scale packed column. Capacity and efficiency data obtained on three sizes of a Raschig-type ceramic ring have been used to establish the basis for the model reliability analysis. Details underlying some aspects of selection of an appropriate algorithm for fitting the data are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.