The 400 series DC Axial Fan proves their reputation as space-saving wonders by moving air for hot or cold air exchange in a wide variety of devices and systems. The outstanding features of axial fans are their small installation depth, low noise level and exceptional efficiency and are particularly well suited for air flow through heat exchangers. Furthermore, with GreenTech EC technology, the axial fan becomes an intelligent energy saver for an extremely wide range of applications. The highly economical brushless motor technology of these fans provides unique variety of intelligent innovations. The DC fans can be operated on voltages that are up to 50% lower and 25% higher than their nominal voltage. This enables the air performance to be adapted to the cooling requirements and allows the noise to be reduced, even if the fan does not have a control input. Closed-loop speed control and function monitoring are becoming increasingly important in many applications.