This centrifugal fan which pushes the air in radial direction is recommended for printing PLA filaments, thus the freshly melted and deposited material has to solidify quickly in order to achieve a good result without curling or deformation.
Therefore, the air stream is directed to the tipo of the nozzle.
The centrifugal fans differ form the axial fans in the manner the aire is distributed. With the same power consumption, the centrifugal fan achieves a higher airflow in a smaller area. This permits to point the airflow directly to the desired spot without affecting the whole printing area (and thus prevent warping).
Also, this fan can be used for any other application that requires air cooling.