Electric ventilation fan noise

Electric ventilation fan noise is mainly from three sources: the bearing friction and vibration, the blades of the vibration and wind noise.
Bearing friction and vibration: not only produce noise and affect performance and shorten the life of the device, reduce the efficiency of energy use, and try to resolve key technical issues in product design.
Electric ventilation fan blade vibration: general fan blades made ​​of plastic has a certain toughness, can withstand a certain degree of physical deformation, vibration will also promote the process of air due to power, but the magnitude is generally smaller . Another more serious vibration blades uneven mass distribution, the center of mass and the axis of rotation exists due to the eccentricity. When the larger fan blade area or eccentricity case, the fan may be driven to even radiators overall vibration, and then spread to the entire chassis. If this occurs, you should doubt the a fan quality work state.
Wind noise: between the air flowing impulse interference, the friction with the surrounding objects, the separating action of the blades on airflow, periodically blowing the pulse power, and will generate noise. The faster the air flow velocity, turbulence is the more often the greater the wind noise was acceleration increases as the wind speed increases, and will. Adversely affect ordinary axial fan in the gap between the blades and the frame flyback airflow, resulting in a larger wind noise at the same time, more interested in the amount of wind, it is precisely because the folded edge, the side air intake and improved design .