How to calculate EFU rated air volume? Conversion of equipment end air supply area and target wind speed
The basic conversion formula for EFU air volume at the equipment end is Q=A×v×3600. The unit of Q is m³/h, A is the effective air supply area m², and v is the target average wind speed m/s. For example, the effective area is 0.5m², the target average wind speed is 0.45m/s, and the preliminary air volume is 810m³/h. This result still needs to be corrected according to actual working conditions.
Area must use effective ventilation area
The overall machine appearance area includes the frame, structural parts and non-ventilated areas, and cannot be directly substituted into the formula. If only a certain process area within the equipment needs to be covered, the area should also be confirmed based on the effective air supply range and air flow diffusion.
The average wind speed does not mean that it is the same at every point
What is calculated is the average demand. There will be differences in measuring points on the actual wind outlet surface, so the project should also specify the uniformity of wind speed or the allowable range of each measuring point. For semiconductor equipment, local wind speeds in critical process areas are often more important than a single average.
The rated air volume must correspond to the test resistance
The air volume of the same fan differs between free air supply and H14 or U15 filter. The filter model or resistance, air inlet and outlet boundaries, and fan speed should be noted in the technical agreement to avoid failure to reproduce the rated values.
The final resistance working condition determines the adjustment margin
After the filter is used, the resistance increases and the air volume may decrease. When selecting, you can evaluate the operating point under the initial resistance and target final resistance, and confirm whether the speed adjustment range can meet the operating requirements.
Multiple EFUs cannot just do simple addition
When multiple units are paralleled, the total air volume can be used as a preliminary total, but the internal backflow of the equipment, adjacent airflow and structural obstruction may cause uneven distribution. Grid measurements should be taken on critical areas.
FAQ
Is it necessary to add a safety factor when calculating air volume?
A reasonable amount should be reserved based on filter resistance growth, manufacturing deviation and operating mode, and it is not recommended to enlarge without basis.
Who determines the target wind speed?
It is usually determined by the equipment process, pollution control objectives and verification results.
Why do we multiply by 3600 for unit conversion?
Because wind speed is measured in seconds, air volume is often measured in hours, and 1 hour is equal to 3600 seconds.
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: The EFU demand air volume can be calculated based on the effective air supply area and the target average wind speed, but the calculated value is only a starting point. The actual selection also needs to consider the resistance caused by the filter, box, air inlet and outlet, and the internal structure of the equipment.
