CFD simulations were used to determine mass transfer coefficients and power consumptions in channels filled with non-woven net spacers. The geometric parameters of a non-woven spacer were found to have a great influence on the performance of a spacer in terms of mass transfer enhancement and power consumption. The results from CFD simulations indicate that an optimal spacer geometry exists. Mass transfer coefficients and power consumptions were determined experimentally by the limiting current method and pressure drop measurements. Close agreement between experiments and simulations was observed.