Depending on the require­ments and appli­ca­tion, either an AC, EC, or DC motor is used – mainly as an external rotor motor. This is because the impeller can be mounted directly onto the rotor. This makes the impeller motor unit extremely short and compact, creating more space for air flow.

Of course, the impeller is an elemen­tary compo­nent. The impeller is crucial for air accel­er­a­tion and gener­ating work in the form of pres­sure. Across all of the designs, the air is drawn in parallel to the axis of rota­tion and flows out again according to the blade char­ac­ter­is­tics. For axial fans, for example, the air flows out mainly parallel to the axis. For safety reasons, the impeller blades are often fitted with guard grills so that no one can hurt them­selves on them. To achieve good effi­ciency, an axial fan’s impeller should be posi­tioned in a fan housing that has been aero­dy­nam­i­cally opti­mized. Together with a front plate, this ensures air flow control and provides the sepa­ra­tion required between the intake and outlet sides.

Due to the different types of flow through the impeller, the fan designs have different oper­ating char­ac­ter­is­tics. If oper­ated using an EC motor, commu­ta­tion elec­tronics are required. The sensors inte­grated in the motor allow the elec­tronics to precisely detect the posi­tion of the rotor in rela­tion to the coils. To that effect, the coils are ener­gized and the rotor is turned. In addi­tion, the built-in elec­tronics process control signals and store status infor­ma­tion.

Regard­less of the fan type and purpose, addi­tional noise insu­la­tion is useful for oper­a­tion in noise-sensi­tive areas. For this purpose, a Flow­Grid is mounted on the intake side of the fans – for a lower noise level and a dras­ti­cally damp­ened blade passing noise. As a result, the air perfor­mance remains unchanged.

If all of the parts are opti­mally matched, the fan is able to meet the require­ments with respect to oper­ating condi­tions, perfor­mance, and envi­ron­mental influ­ences.