The Basics of Cabinet-Type Centrifugal Exhaust Fans and How to Reduce Airflow

The Basics of Cabinet-Type Centrifugal Exhaust Fans and How to Reduce Airflow

Many people are not particularly familiar with cabinet-type centrifugal exhaust fans. In fact, this device is a variable-flow, constant-pressure unit. This means that when the speed is constant, pressure and flow theoretically follow a linear relationship curve. However, due to certain internal losses, the actual characteristic curve is distorted. In practice, the operation of a cabinet-type centrifugal exhaust fan may be affected by some external factors. Among these, changes in inlet air temperature and density have a significant impact on pressure. Analysis shows that, for a given air intake volume, the pressure generated under lower inlet air temperature conditions is relatively lower. When operating at a constant speed, considering the airflow, a decrease in inlet air temperature will result in an increase in the required power. In practical applications, some users may wish to appropriately reduce the airflow of a cabinet-type centrifugal exhaust fan. How can this be achieved? In fact, there are four methods to consider. One is to use a frequency converter or adjust the pulley ratio to reduce the pulley speed. Second, since the propeller diameter can be reduced, the airflow can be decreased. The third method involves appropriately reducing the outlet width of the cabinet-type centrifugal exhaust fan’s impeller to decrease the flow area, thereby reducing the air volume. The fourth method involves reducing the number of blades; however, even if the number of blades is reduced, the airflow may not necessarily decrease. Specific situations require evaluation based on actual conditions. The above overview covers the main characteristics of cabinet-type centrifugal exhaust fans and four methods for reducing airflow. I hope that by understanding this information, everyone can gain a better understanding of the equipment and utilize cabinet-type centrifugal exhaust fans more effectively.