The pressure increase of the centrifugal fan is mainly based on the working principle of the centrifugal fan.

Because the centrifugal fan is based on the principle of converting kinetic energy into potential energy, it uses a high-speed rotating impeller to accelerate the gas, then decelerates, changes the flow direction, and converts kinetic energy into potential energy (pressure).

In a single-stage centrifugal fan, the gas enters the impeller from the axial direction, changes direction as the gas flows through the impeller, and then enters the diffuser. In a diffuser, the gas changes direction of flow causing a deceleration, which converts kinetic energy into pressure energy. The increase in pressure occurs mainly in the impeller and secondarily in the diffusion process. In a multi-stage centrifugal fan, a reflux device is used to direct the airflow to the next impeller, creating higher pressure.