When choosing FFU for an ISO 5 clean room, which parameters are worth looking at?
Direct answer: First look at the area covered by ISO 5 and the acceptance operation status, and then look at the effective air volume of the FFU under the specified filter and actual resistance, the static pressure corresponding to the target air volume, air outlet uniformity, filter efficiency and sealing. Power supply, control, power consumption and maintenance space must also be confirmed simultaneously. Whether it ultimately reaches ISO 5 will be determined by on-site particle concentration and air flow testing.
ISO 14644-1 classifies clean rooms and clean areas based on the concentration of suspended particles in the air. Therefore, ISO 5 is the cleanliness result to be achieved by the project and cannot be directly regarded as the fixed air volume, wind speed or filter model of a certain FFU.
Level 1: Define the results to be achieved by the project
It should be clear whether ISO 5 covers the entire room or a local clean area near the equipment, which locations the process focuses on controlling, and under what operating conditions it is accepted for acceptance. The dust generated by personnel and equipment and the return air path will also affect the FFU layout and air flow direction.
This step determines the air supply requirements. Only 'ISO 5' and room area are provided, which is usually not enough to determineFFU specifications。
Second level: Check the FFU machine parameters
In supplier information, the most important things to compare under the same working conditions are:
The effective air volume after installing the specified filter, and the static pressure corresponding to the target air volume;
Outlet wind speed and uniformity;
HEPA or ULPA filter efficiency, resistance under design air volume and box sealing;
Power consumption, noise, speed regulation and communication functions in commonly used gears;
Ceiling or equipment end dimensions, space for wiring and filter changes.
The maximum air volume and maximum static pressure may correspond to different operating points and cannot be directly combined into design conditions. If the filter grade or model is changed, the fan operating point and the overall air volume should be rechecked.
The third level: Use field data to determine whether it is truly applicable
The qualified performance of the FFU prototype is one of the basis for entering batch configuration; after installation, the air volume, airflow distribution and particle concentration at key locations must still be checked. The technical protocol should indicate the test method and operational status.ISO 14644-3 provides test methods to support cleanroom performance evaluation and differentiate between different airflow types and operating conditions.
If on-site particle concentrations do not meet targets, the problem may not necessarily be with the filtration level. The air supply and return organization, FFU operating gear, equipment shielding, filter sealing and personnel movement conditions should also be checked before deciding on an adjustment plan.
Aili Industrial can combine the ISO 5 regional scope, process requirements, target air volume, filter configuration and installation drawings to match fans, motors, filters, cabinets and control solutions. For batch projects, it is recommended to verify the prototype first, and then write the complete machine working conditions, testing requirements and on-site acceptance methods into the technical agreement. The specific performance is subject to the actual measurement results of the project.
When selecting a model, you can use one sentence to check whether the information is complete: Can the supplier explain 'how to test the air supply performance of the FFU under the specified filter, specified gear and target air volume'? If only isolated maximum parameters can be provided, project condition data still need to be supplemented.
