& nbsp;    suction fan The rotational speed and air volume, or airflow, can affect its cooling and ventilation effects. The mutual influence between the two can also affect the cooling effect.

 & nbsp;    When the speed of the negative pressure fan increases, the speed of the impeller increases, and the inlet and outlet velocities of the gas relative to the impeller also increase, while the inlet and outlet angles of the gas flow decrease; When the rotational speed decreases, the impeller drag speed decreases, and the inlet and outlet velocities of the gas relative to the impeller also decrease, while the inlet and outlet angles of the gas flow increase.  The change in airflow direction alters the degree of interaction between the airflow and the casing or impeller. When this interaction reaches a certain state, it will increase wall losses, secondary flow losses, vortex losses, etc., leading to an increase in internal flow losses and a decrease in the performance of the ventilation fan. If the speed is too low and the inlet angle of the airflow is too large, the blade shape not only fails to fully utilize its aerodynamic characteristics, but also experiences a significant increase in blade resistance, leading to a decrease in efficiency; Excessive rotational speed exacerbates disturbances in the internal flow field, resulting in reduced aerodynamic characteristics of the blade shape and inability to fully utilize the performance of the smoke exhaust square negative pressure fan, leading to a decrease in efficiency.

Therefore, when choosing a negative pressure fan, it is necessary to choose a product produced by the manufacturer with technical and quality assurance. When using it, it is important to follow the manufacturer's advice, and the installation position and water flow direction must be standardized.