|Attenuator position relative to axial fan|
Don't site pod attenuators immediately upstream of the fan as the attenuator pod will block the air flow to fan impeller. However, if the pod is the same size or smaller than the impeller hub bolting directly to the fan is acceptable.
Allow the diameter of straight duct between pod attenuator and the fan inlet to ensure impeller obtains an even flow of air.
Propriety information courtesy of FANTECH (Australia)
(NOT TO BE REPRODUCED)