The connection method between the duct fan and the air duct will directly affect the overall ventilation efficiency, among which sealing is the key factor. If there is a gap in the connection, the airflow generated by the duct fan during operation will leak from the gap, resulting in a decrease in the actual air volume entering the air duct. Leakage not only reduces the effective ventilation volume, but also generates additional resistance due to airflow turbulence, requiring the duct fan to consume more energy to maintain the preset ventilation effect, thereby reducing the overall efficiency. A tight connection can avoid this loss, allowing all airflow to enter the air duct to ensure that the ventilation efficiency is not affected.
The adaptability of the connection also has a significant impact on the ventilation efficiency. When the size of the air duct does not match the air outlet of the duct fan, forced connection will cause the airflow to suddenly contract or expand at the interface, forming turbulence. Turbulence will increase the resistance to airflow flow, resulting in wind pressure loss, and reducing the airflow delivery speed in the air duct. The size-matched connection method can make the airflow transition smoothly, reduce the energy loss caused by cross-sectional changes, keep the airflow at a stable flow rate, and improve ventilation efficiency.
The smoothness of the connection affects the flow state of the airflow. If the connection method causes bulges or wrinkles at the interface, the airflow will be blocked by these obstacles when passing through, forming local vortices. The vortex will consume the kinetic energy of the airflow, reduce its forward momentum, and may cause the air duct to vibrate, further exacerbating energy loss. Smooth connections allow the airflow to flow along a continuous channel, reduce obstacles, and make more full use of the airflow energy, thereby maintaining a high ventilation efficiency.
The use of flexible connections will change the stability of ventilation efficiency. When using flexible materials such as canvas for connection, if the material is too loose or twisted during installation, it will vibrate under the impact of the airflow, causing the cross-section of the air duct to change continuously, resulting in the airflow speed to fluctuate. This unstable airflow state will increase energy loss and affect the uniformity of the ventilation effect. A properly tightened flexible connection can not only buffer the vibration transmission between the duct fan and the air duct, but also keep the channel stable, allowing the airflow to continue to flow efficiently.
The firmness of the connection affects the stability of efficiency during long-term use. If the connection is loose, the vibration of the duct fan during operation will gradually expand the interface, and the original slight leakage will intensify over time, and the ventilation efficiency will continue to decline. At the same time, loose connections may cause relative displacement between the duct and the duct fan, further destroying the stability of the airflow. A firm connection can avoid this situation, keep the interface in good condition for a long time, and ensure that the ventilation efficiency does not significantly decrease during use.
The angle design of the connection will also affect the airflow delivery efficiency. When the duct and the duct fan outlet are connected at right angles, the airflow needs to change direction suddenly, which is easy to form backflow at the corner, hindering the subsequent airflow and causing wind pressure loss. The use of a gradual bend connection method allows the airflow to change direction slowly, which can reduce the backflow phenomenon, reduce resistance, and allow the airflow to enter the duct more smoothly, maintaining a high delivery efficiency.
The wind resistance resistance of the connection part is directly related to the ventilation efficiency. Different connection methods will form different wind resistance coefficients. Connections with low wind resistance can allow airflow to pass easily, while connections with high wind resistance will significantly hinder airflow. For example, the use of flange connection and sealing gaskets can form a smooth interface with low wind resistance; while the simple bundling connection method may cause the interface to be uneven and have high wind resistance. The difference in wind resistance is directly reflected in the ventilation efficiency. The smaller the wind resistance, the higher the ventilation efficiency.
