摘要 |
A centrifugal fan is provided, in which the value of static pressure with respect to the flow rate, namely, the flow rate - static pressure characteristic may be set to a relatively arbitrary value without increasing noise. An impeller of the centrifugal fan comprises an impeller body, a plurality of stems, a blade mounting member, a plurality of main blades, and a plurality of sub blades. The main blades are shaped to suck air into a casing through a suction port when the impeller rotates in a direction of normal rotation. The sub blades are shaped to suck air into the casing through the suction port when the impeller rotates in a direction of reverse rotation opposite to the direction of normal direction. |