The effect of fluid physical properties on the hydrodynamic behaviour in a packed column with 1.5” and 2.5” fourth generation random packing was investigated by measuring the pressure drop and liquid hold-up. Experimental data for combinations of four liquids and two gases were measured for both packings in a pilot plant setup with a column inside diameter of 393 mm and a packed bed height of 3 m. Liquid superficial flow rates in the range of 6 – 122 (m3/h)/m2 and gas rates up to the flooding point were considered. The results provide significant extended information on how fluid properties affect the hydrodynamic behaviour in randomly packed columns. As expected, larger packing pieces enable higher hydrodynamic throughputs. However, the choice of packing size remains a balance between improved capacity (larger packing) and improved separation efficiency (smaller packing).