In this work, polysulfone hollow fibers with oxygen permeance 70 L (STP)/(m2·h·bar) and selectivity α(O2/N2) = 6 were obtained. A decrease in the dope solution temperature allowed to diminish macrovoids due to the increase of the dope viscosity from 15.5 Pa·s at 62 °C to 35 Pa·s at 25 °C. To reduce the fiber diameter, thereby increasing the packing density, they were spun at high linear velocities. A hollow fiber membrane element was produced with effective membrane area 2.75 m2 and packing density 53%. Its air separation performance was evaluated to bridge laboratory studies and practical application.