ebm-papst GreenTech EC Compact ACi4400 Tubeaxial Fans offer up to 75% energy savings compared to same-size AC fans. The drive concept of these fans is based on ebm-papst's Green Tech EC technology with outstanding motor efficiency. With less intrinsic heating in the motor having a direct, positive effect on the bearing system, the fans have a service life that is up to 85% longer than fans using shaded-pole motors. Expensive replacement fans and maintenance down times are kept to a minimum. The ACi4400 Tubeaxial Fans from ebm-papst are quieter than typical AC fans: as much as 6 dB(A) quieter. Speed, air flow, and operating noise are independent of the supply voltage and power frequency. Voltage fluctuations and frequency differences in the power system are compensated for automatically.