When looking for a DC or AC fan for your application, two factors to keep in mind are sound performance and airflow direction. The three basic fan types - Axial, Centrifugal, and Blower - all have different properties that dictate how they’re used in an application.
Different types of fans have different audible noise performance, both in the overall noise volume of the fan and in how high-pitched and ‘whiny’ that noise is. A louder centrifugal fan may be easier on the ears than a quieter but much whinier axial fan. These three fans also each move air in different ways, which suits them to different needs in your system.
|Audible Noise Pitch||High||Low||Low|
|Audible Noise Level||High||Moderate||High|
|Airflow Direction||Pushes air one way, perpendicular with the fan’s face||Air is pushed in all directions from the fan’s outside edge||Air is strongly pushed in a single direction 90 degrees from the intake|
This diagram shows the different types of fan in action. Red arrows show the direction and location of the fan’s air intake, blue arrows show the direction of the fan’s rotation, and green arrows show the direction of the fan’s exhaust - where it’s blowing air.