A novel uniflow cyclone design was evaluated using three prototype cyclones. For the first two, the efficiency and Euler number were determined using airborne solid particles with a number mean diameter of 12.5 mu m. Then a larger scale prototype based on the optimized geometry was compared with an existing conventional high efficiency cyclone and a vane-induced uniflow cyclone, using mineral oil droplets with a number mean diameter of 8.9 mu m. Both sets of experiments showed that the newly designed cyclone had a higher efficiency at a higher pressure requirement, in addition to the feature of a small footprint.