Patent attributes
A ventilating fan includes a sirocco fan disposed in a box-shaped body and an adapter connected to an air outlet of the sirocco fan. The sirocco fan is composed of two opposite scroll plates with scroll shapes and a casing plate sandwiched between the two scroll plates. An overall air inlet of the sirocco fan is disposed on the first scroll plate and a central line of the air outlet of the adapter is offset towards the second scroll plate. The present invention is advantageous in that no turbulence is generated at the adapter and the wind amount of the ventilating fan is thus ensured and noise is reduced. Therefore, the present invention can provide a small air blowing device with high efficiency and improve stability of performance of the product.