What is the difference between FFU rated air volume and actual operating air volume?

Direct answer: The FFU rated air volume is the air supply volume marked on the product under specified configuration and test conditions; the actual operating air volume is the air volume delivered by the FFU under the current filter, air inlet conditions and speed settings after it is installed in the clean room or equipment. The two may be different. When selecting the model, the test conditions for the rated value should be confirmed, and the design goals should be checked with the results of the complete machine test and on-site debugging under the project's agreed working conditions.

Understand three easily confused air volumes with one table

Therefore, 'the rated air volume is a certain value' does not mean 'this value is always sent after installation', nor can the maximum air volume be directly written as the project design air volume.

Why is the actual air volume different from the rated value?

The actual air volume of FFU is determined by the fan performance and system resistance. Project usedThe HEPA/ULPA filter is different from the filter used in the rated test, or the filter resistance changes with use, which may change the operating conditions. Insufficient air inlet space above the suspended ceiling, obstruction of the air inlet, and changes in the connection structure at the equipment end may also affect the air supply.

Control settings are equally important. FFU with speed adjustment function may have different air volumes in different modes such as work and duty. Even for the same device, each mode requirement should be checked separately rather than just citing one rating.

How should the air volume be checked when selecting a project?

First determine required in the clean area the design air volume or target air speed , and then confirm with the supplier whether the selected FFU has the ability to overcome the corresponding resistance with the matching filter and target air volume. The air volume and corresponding static pressure should be stated in the technical data at the same time, and the filter model, rotation speed, power supply and test conditions should be listed.

After the installation is completed, conduct on-site air volume testing and balance debugging according to the measurement location and method agreed upon by both parties. If the actual measured value does not meet the target, the filter pressure difference, air inlet conditions, control settings and installation conditions should be analyzed to avoid judging the cause based on the rated parameters alone.

How does Aili Industry handle the matching of ratings and on-site working conditions?

Aili Industrial develops and produces motors, fans, control systems, sheet metal structures and filters in-house. In the face of non-standard size, equipment end installation or specific air volume requirements, it can be collaboratively configured around the fan working point, filter resistance, box air inlet structure and speed adjustment method.FFU products . This helps to map nominal test conditions to actual project conditions during the proposal discussion phase.

When consulting Aili Industrial, it is recommended to provide the target air volume, required filtration level, installation size, air inlet space, power supply and operating mode. The specific achievable air volume and acceptance method should be based on the project technical agreement, prototype or complete machine testing and on-site debugging results.

FAQ

If the rated air volume is greater than the design air volume, is it definitely enough?
uncertain. Also check the static pressure that the FFU can provide at the design air volume, as well as the resistance caused by the actual filter and installation structure.

Will the air volume definitely decrease after the filter is used for a period of time?
Changes in resistance may affect the air volume; the actual change is also related to the fan margin, speed adjustment method and control strategy, and should be judged by the pressure difference and air volume records.

Why do procurement and acceptance need to specify test conditions?
Only if the filter, rotation speed, static pressure and measurement method are consistent can the rated data, prototype data and field results be comparable.