There are two kinds of centrifugal fan installation, left-handed and right-handed. There are two ways to judge whether the centrifugal fan is left-handed or right-handed. One way is to face the fan inlet and observe the rotation direction of the fan impeller. If it is clockwise, it is left-handed. If it is counter-clockwise, it is right-handed.
Another way is to face the fan from the side of the motor. If the impeller rotates clockwise to right and counter-clockwise to left, do not confuse the discriminant basis of the two ways.