The optimum heat and mass transfer area at which minimum cost exists throughout the technical life of forced draft counter cooling tower is studied in the present work. Original formula are developed and presented for the best thermo-economical performance as a design point. Also in this paper an investigation is made using measurements of the mass transfer rates and pressure drops for a comprehensive range of PVC plastic packing producing an economic comparison to find the best geometry and range. In order to do this, heat transfer and pressure drop for turbulent conditions in fills used in the modern cooling tower have to be studied. A new method of comparison for existing cooling tower fills has been developed and the performance of the best packing has been expressed in relation to the ideal packing.