With a computer-optimized blade design for maximum performance, Model EMAX4 provides up to 77 percent total efficiency, says its manufacturer. The fan design reduces noise by 2 to 3 dB and energy consumption in air-cooled condensers, commercial refrigeration, chillers, cooling towers and evaporators. Users can customize the fan for motor speed, airflow, space and additional application requirements. A modular design, the high efficiency fan is available with 5, 6, 7, 9 or 12 blades in diameters from 22 to 36” (559 to 914 mm). Pitch angles include 20° to 48.5° in 3.5° increments. Fan blades are constructed of glass-reinforced polyamide (PAG), and the hub is made from pressure-die-cast silicon aluminum alloy.