When FFU switches working modes, how should the air volume and static pressure match?

Direct answer: For each planned operating mode, the target air volume should be confirmed separately, as well as the FFU's ability to overcome filter and actual system resistance at that air volume. Just because the production mode is qualified does not mean that the low speed or standby mode can also meet the cleanliness requirements. The selection should compare the air volume and static pressure data of the same filter, the same gear and the same test conditions.

Clean room and equipment-side FFU may adopt fixed operation, step-by-step speed regulation, zone control or centralized group control. Changing the working mode usually also changes the fan speed, air supply volume and airflow distribution. therefore,The working mode of the FFU fan filter unit should be determined together with the process requirements at the design stage, rather than just setting the gear based on energy saving needs.

First clarify the air supply target for each mode

The project should list the operating status of planned use such as production, non-production and maintenance, explain the cleanliness, target air volume or wind speed that needs to be maintained in each area in the corresponding status, and whether the air supply is allowed to be adjusted.

For equipment with local high cleanliness requirements, the operational relationship between the FFU at the equipment end and the production equipment should also be clarified. The mode name is just a control setting. The actual air volume provided by 'low speed' must still be judged based on product performance data and field testing.

Check static pressure at target air volume

For each gear intended to be used, the FFU assembly specification should be checkedAfter HEPA or ULPA filter , can the target air volume of this mode be achieved under the project resistance conditions. Performance data provided by the supplier should indicate filter configuration, operating gear, static pressure measurement location and test method.

'Maximum air volume' and 'maximum static pressure' may come from different working points and cannot be paired directly. What is more valuable is to check the performance data corresponding to the target air volume and confirm that the resistance caused by the filter and installation structure has been included in the calibration.

How will each mode operate after the resistance changes?

The resistance may rise after the filter is running. At a fixed gear, the actual air volume may decrease; if the control system maintains the air volume by increasing the rotational speed, the operating gear, power consumption and noise may change. The project should agree on resistance monitoring and air volume review requirements to confirm that the FFU can meet the air supply targets of each mode during the normal maintenance cycle.

Low-speed modes especially require field verification. If the filter efficiency meets the requirements, it does not mean that the air flow and cleanliness of the work area are still qualified after the air supply volume is reduced.

Controls and tests should cover actual usage patterns

For projects that require multiple FFUs to operate collaboratively, partitions, mode switching rules, communication interfaces, and abnormal feedback should be determined in advance. useWhen FFU group controls the system , it can be verified during the prototype stage whether the control instructions are consistent with the actual operating status of FFU.

Prototypes and field tests should cover the main modes planned to be used in the project, and record the air volume, wind speed distribution, filter pressure difference, power consumption and related area pressure difference in each mode. Only when the test results of the agreed mode meet the technical agreement can it be used as a formal operational setting.

Aili Industrial can match the fan, motor, filter and complete machine control scheme based on process operation time, cleanliness goals, filtration requirements and control needs. For batch projects, it is recommended to first confirm the performance of each mode of the prototype, and then write the filter configuration, gear settings and test methods into the technical agreement. Specific performance is subject to test results under project conditions.

Q: If the air volume at the highest gear reaches the standard, can the lower gear be put into use?
Answer: We cannot judge directly. For low-speed gears, the actual air volume, airflow distribution and cleanliness need to be checked.

Q: The higher the static pressure, the more flexible the FFU’s working mode is?
Answer: Not necessarily. The performance at each target air volume should be viewed, and the speed range, power consumption and noise should be checked at the same time.

Q: What data should a multimodal project request from suppliers?
Answer: It is recommended to obtain air volume and static pressure data indicating the filter, operating gear and test conditions, and agree on a prototype and on-site verification method.