The description “40x40x20 centrifugal fan” refers to the specifications of a centrifugal fan. Let’s break down the meaning of each component: In summary, a 40x40x20 centrifugal fan refers to a fan with dimensions of 40 mm x 40 mm x 20 mm, designed to operate using centrifugal force to move air. Where are 40x40x20 centrifugal …