Centrifugal fan

A centrifugal fan, comprising:

• a main plate configured to be rotated about a rotational axis;
• a shroud having a suction opening, through which air is suctioned in;
• and
• a plurality of blades arranged between the main plate and the shroud to allow the air suctioned in through the suction opening to flow from a front edge to a rear edge of each blade with respect to a rotational direction of the main plate, wherein, assuming a first cross section, a second cross section, a third cross section, and a fourth cross section of each blade sequentially taken at planar layers, substantially, perpendicular to the rotational axis, from the shroud to the main plate, the rear edge of the each blade between the first cross section and the second cross section gradually becomes farther away from the rotational axis, the rear edge of each blade between the second cross section and the third cross section gradually approaches the rotational axis, and the rear edge of each blade between the third cross section and the fourth cross section again gradually becomes farther away from the rotational axis.

A centrifugal fan, comprising:

• a main plate configured to be rotated about a rotational axis;
• a shroud having a suction opening, through which air is suctioned in;
• and
• a plurality of blades arranged between the main plate and the shroud to allow the air suctioned in through the suction opening to flow from a front edge to a rear edge of each blade with respect to a rotational direction of the main plate, wherein a longitudinal cross section of each blade is convex in a direction opposite to the rotational axis at a portion of the blade near the shroud and is convex toward the rotational axis at a portion of the blade near the main plate.