The selection of FFU (Fan Filter Unit) is strongly dependent on its specific application scenario. Different scenarios have completely different requirements for the performance, material, control, and reliability of FFUs. Ignoring the application scenario in the selection process can lead to insufficient performance, high operating costs, and even production accidents.
Here are the key considerations for FFU selection based on different application scenarios:
I. Electronics and Semiconductor Industry (e.g., Chip, Display Panel Manufacturing)
This is the field with the highest requirements and the most extensive application of FFUs. The core is to control particulate contamination, as even the smallest particles can lead to a decrease in product yield.
Key Requirements:
- Ultra-high cleanliness
- High reliability
- High air volume
- Low vibration
Selection Considerations:
1. Filter Efficiency: ULPA (Ultra-Low Particulate Air) filters must be selected (with a filtration efficiency of ≥99.9995% for 0.12μm particles) to meet the stringent requirements of ISO Class 3-5.
2. Motor Type: EC (Electronically Commutated) motors are preferred due to their high efficiency, precise speed control, and significantly lower heat generation and vibration compared to AC motors, which prevents micro-vibration from affecting precision equipment.
3. External Static Pressure: High static pressure models (≥120 Pa or higher) should be chosen to overcome system resistance and ensure stable airflow throughout the filter's lifespan.
4. Control Method: A networked intelligent group control system must be used, which can be integrated into the facility monitoring system (FMCS) to enable centralized monitoring, speed adjustment, and fault alarms for thousands of FFUs.
5. Material: Generally, galvanized aluminum zinc sheet is sufficient to meet the requirements.
Example Scenarios: Photolithography and etching areas in semiconductor wafer fabs.
II. Biopharmaceutical and Medical Device Industry
The core is to control microbial (bacteria, viruses) contamination and cross-contamination while meeting the GMP regulations for cleanliness and disinfection.
Key Requirements:
- Sterility
- Dust-free
- Corrosion resistance
- Easy to clean and disinfect
Selection Considerations:
1. Casing Material: Stainless steel (SUS 304 or SUS 316) must be selected. Its smooth surface, non-shedding, and corrosion resistance allow it to withstand repeated cleaning and disinfectant wiping.
2. Filter Efficiency: HEPA (H13/H14) filters are sufficient for key areas (Class A/B clean zones) to effectively remove bacteria.
3. Sealing Performance: Extremely high sealing performance is required to prevent the leakage of external contaminants. Liquid gasket sealing or high-quality gel sealing are common choices.
4. Filter Replacement: A bottom replacement design is recommended to prevent maintenance personnel from entering the technical plenum, thus avoiding cross-contamination and ensuring safer replacement operations.
5. Surface Treatment: All corners should be rounded to eliminate dead angles and facilitate thorough cleaning.
Example Scenarios: Sterile injection filling lines, vaccine production workshops, and sterile implantable medical device production workshops.
III. Healthcare Institutions (e.g., Hospital Operating Rooms)
The core is to provide a locally ultra-clean environment for surgery to protect patients from infection and ensure the safety of medical staff.
Key Requirements:
- Low noise
- Safety
- High efficiency
- Easy maintenance
Selection Considerations:
1. Noise Level: Low-noise models (≤52 dB(A)) must be selected to create a quiet and focused surgical environment for medical staff.
2. Filter Efficiency: HEPA (H13/H14) filters are typically used in the operating room's ceiling supply air diffusers.
3. Structural Design: Often integrated with the operating room's dedicated supply air ceiling casing to form a laminar flow supply air ceiling. The FFU must be compatible with it.
4. Reliability: Stable operation with low failure rates is required, and it is best to have a redundant backup design.
5. Material: Usually stainless steel or high-quality powder-coated material, which is easy to disinfect and clean.
Example Scenarios: Hundred-level and thousand-level laminar flow purification operating rooms.
IV. Food, Beverage, and Cosmetics Industry
The core is to prevent product contamination by microorganisms to extend shelf life while being corrosion-resistant and rust-proof.
Key Requirements:
- Hygiene
- Corrosion resistance
- Mold prevention
Selection Considerations:
1. Material: Stainless steel should be chosen for areas in contact with products or high-humidity environments to prevent rust and corrosion.
2. Filter Efficiency: HEPA filters (H13) should be selected according to hygiene standards to effectively filter out mold and spores.
3. Surface Treatment: All surfaces should be smooth, without dead angles, and easy to clean to prevent bacterial growth.
4. Sealing Performance: Good sealing to prevent external contaminants from entering the production area.
Example Scenarios: Sterile filling rooms for yogurt and beer, packaging workshops for milk powder.
V. Laboratories and Research Institutions (e.g., Biosafety Laboratories, Animal Rooms)
The core is to ensure the accuracy of experimental results and prevent the leakage of hazardous microorganisms to protect personnel and environmental safety.
Key Requirements:
- Absolute safety
- Sealing
- Leak prevention
Selection Considerations:
1. Safety Design: FFUs used in BSL-3/4 laboratories must be capable of in situ disinfection (e.g., fumigation) and are often designed for disposable or bag-in/bag-out replacement to ensure absolute safety during the replacement process.
2. Pressure Control: FFUs need to be interlocked with the laboratory's exhaust system to maintain the room's negative (or positive) pressure gradient and prevent the escape of hazardous aerosols.
3. Material and Sealing: Fully constructed from 304 or 316 stainless steel by welding, with extremely high airtightness.
4. Filters: Must be high-efficiency filters with a scan leak test port.
Example Scenarios: P3, P4 biosafety laboratories, SPF-grade animal rooms.
Summary:
When selecting an FFU, one must not simply focus on performance and price. It is essential to first clarify the application scenario and then deduce the required technical parameters and material characteristics based on the core requirements of that scenario. Only in this way can the most suitable, economical, and longest-lasting product be selected.
