R3G190-RC05-03 Fan Blower, EC Centrifugal, 240 V, AC, 190 mm, 71.4 mm. RadiCal fans are one piece backward-curved impellers made of high-tech composite material. These centrifugals feature highly efficient GreenTech EC technology providing low-pressure solutions with backward-curved blades, used primarily as intake fans and do not require a scroll housing.