Why should we consider both air volume and static pressure when selecting EFU? Equipment working point confirmation method
Direct answer: EFU selection cannot look at air volume and static pressure separately. Air volume answers 'how much air needs to be sent', and static pressure answers 'can the fan still send out this air when there is resistance from the filter and equipment'. Only when the target air volume is marked under corresponding static pressure and filter operating conditions can the parameters be comparable.
Define the target air volume first
The target air volume can be initially converted from the effective air supply area and the target average wind speed, or it can also be derived from equipment process verification. What is obtained here is the demand, which cannot be directly used as the result of fan selection.
List sources of system resistance
The initial and final resistance of the filter, the air inlet grille, the box air duct, the equipment guard and the air outlet side mechanism will all consume static pressure. The project should try its best to provide resistance data or equivalent structures, and should not just require an air volume value that is out of working conditions.
Identify operating points on performance curves
The intersection of the fan performance curve and the system resistance curve determines the actual air volume. When selecting the model, you should confirm the static pressure, rotation speed and input power corresponding to the target air volume point, and avoid taking the free air supply volume as the installed air volume.
Check the initial resistance and final resistance at the same time
New filters have different resistance than those that have been used for a while. The normal gear should meet the initial working conditions and reserve speed adjustment space for resistance growth; the filter should be replaced after reaching maintenance conditions instead of infinitely increasing the speed.
Confirm with complete machine test closed loop
The prototype or first device should measure air volume, static pressure, wind speed at multiple measuring points, uniformity, power and noise in a state close to the actual installation. The test report should record the filter, rotation speed and air inlet and outlet boundaries.
Project confirmation checklist
Confirm items |
What needs to be clarified |
Installation conditions |
Available length, width and height, air inlet and outlet directions, interfaces and maintenance space |
Air parameters |
Target air volume, wind speed, static pressure and uniformity |
Filtering requirements |
Efficiency ratings, resistance, sealing and testing methods |
Electrical control |
Power supply, speed regulation, communication, linkage and abnormal logic |
Acceptance conditions |
Test conditions, measuring points, instruments and judgment standards |
FAQ
Can EFU selection be completed by providing only the target air volume?
It cannot be done accurately and requires filter resistance, equipment additional resistance and installation boundaries.
Is the higher the EFU static pressure, the better?
no. The target system resistance should be met with a reasonable margin; over-amplification may increase power and noise.
Is it okay to directly increase the speed when the air volume is insufficient?
It can be used as a debugging method, but the air inlet obstruction, filter pressure difference, structural obstruction, power and noise should be checked at the same time.
How does Aili Industry cooperate with equipment-side EFU projects?
Aili Industry carries out R&D and production around EFU complete machines, fans and motors, control systems, sheet metal structures and air filters. For equipment-side projects, configuration can be carried out based on equipment drawings, target air volume, static pressure, filtration efficiency, installation interface and control logic. When it comes to ultra-thin, small size or special interfaces, it is recommended to confirm the drawings and agreed working conditions first, and then test the curing parameters through the prototype so that the configuration can be consistent in subsequent mass production.
During project consultation, the available internal length, width and height of the equipment, target cleanliness, air supply area, air volume or wind speed requirements, filtration efficiency, power supply and communication methods can be provided to facilitate quick judgment of whether standard products are suitable or whether non-standard design is required.
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Conclusion: EFU air volume represents the air delivery volume, and static pressure represents the ability to overcome resistance. When selecting the model, you must check both under the same working conditions and explain the filter, rotation speed and installation boundaries to determine the actual working point after installation.
