Impellers of vacuum fans undergo heavy wear and tear. The replacement of impellers can lead to extended down times. TMQS has conducted extensive tests of impellers of different materials, coatings, and blade geometrics. The gained experiences are reflected in the new, open impeller VE design. The optimized blade geometry, material strength, as well as the usage of specially developed materials make the new TMQS impeller to become more wear resistant, to increase its vacuum power, to reduce heat development, and to have an increased life time.