Installation Precautions For Large-scale DC FFU Fan Filter Units

The installation of large-scale DC FFUs (fan filter units) is a systematic project, not simply a matter of "hanging them up and connecting them online". The installation quality directly determines the operational effectiveness, energy consumption level, and long-term stability of the clean room. The following are detailed precautions, which can be divided into three stages: planning and preparation, installation and implementation, and debugging and verification.

This is the most crucial step that determines the success or failure of the installation work.

• On site survey and review:
• Ceiling Grid System: It is necessary to accurately measure the installation accuracy of the ceiling keel (such as T-Bar keel). Check its flatness, levelness, strength, and stability. The weight of the FFU after installation will be evenly distributed on the keel, and it must be ensured that it can bear weight without deformation.
•  Plenum sealing: The space above the ceiling where FFU is installed must be a well sealed and leak free space as a Plenum. All wall panel joints, through wall holes, etc. must be strictly sealed with sealant, otherwise it will cause pressure difference disorder and cleanliness non-compliance.
• Space size: Check whether the physical size of the FFU matches the reserved opening size of the ceiling to ensure that the FFU can be smoothly inserted.
•  Logistics and warehousing:
•  Batch delivery: Coordinate with the supplier to deliver the goods to the site in batches and in an orderly manner according to the installation progress. Avoid stacking thousands of FFUs on site at the same time, which may cause management confusion, crushing damage, or loss.
• Storage Environment: FFUs, especially their core components HEPA/ULPA filters, must be stored in a clean, dry, rain and moisture resistant environment. The packaging box should be kept upright and should not be squeezed or stacked.
• Technical briefing and training:
•  All staff training: Provide unified training for all installation personnel, including installation procedures, operating standards, precautions (especially filter protection), safety instructions, etc. Ensure that all personnel understand and adhere to the same standards.
• Sample guide: First, select a small area (such as 4 FFUs) for sample installation. Invite the owner, supervisor, and manufacturer to jointly inspect the sample, confirm the installation method, wiring, aesthetics, etc., and use this as the standard for subsequent large-scale installations.

At this stage, it is necessary to strictly follow the procedures, pay attention to details and quality.

•  Installation of FFU body:
• Handle with care: FFU is a precision equipment, and collision and compression must be strictly prohibited during handling and installation, especially the high-efficiency filter at the bottom.
•  Protection of filter: Before installation and commissioning, do not remove the protective film on the surface of the filter to prevent dust from clogging the filter screen. It can only be removed after the system is purged and before operation.
• Put the FFU in place stably: place the FFU in the ceiling grid stably, adjust the gasket or clamp around to ensure that it is closely and evenly fitted with the ceiling frame, without gaps, and prevent air leakage.
•  Direction Consistency: Ensure that the airflow direction (direction arrow) of all FFUs is consistent.
•  Electrical wiring:
• Power off operation: All wiring work must be carried out with complete power off to ensure safety.
• Standardized wiring: Strictly follow the FFU wiring diagram for wiring, and ensure that the neutral wire (N), live wire (L), and ground wire (PE) are correct and error free.
• For group control systems, the DA/DB (or A/B) polarity of the communication bus (such as RS-485) must be consistent, and reversing it will cause the entire network communication to fail. It is recommended to use twisted pair cables with uniform colors and connect them in the same order. The power line and communication line should be wired separately to avoid interference.
•  Cable Management: Power and signal lines should be fixed with hoses or cable trays, neat and beautiful, with allowance to avoid pulling. Special connectors should be used at the joints, and simple winding is strictly prohibited.
• Finished product protection: During the installation process, protective measures should be taken for the already installed FFU, such as covering it with a dust cover, to prevent dust, paint, cement, and other pollutants from subsequent decoration operations or damage to the equipment.

Debugging after installation is the guarantee to ensure that the system runs as designed.

•  Preliminary inspection: Check if all FFUs are securely installed and if the wiring is correct and secure. Power on the system.
•  Single point testing:
•  Manual start stop: Manually start each FFU locally, confirm that the fan rotates correctly, runs smoothly, and has no abnormal noise.
• Address Setting and Communication: In the group control system, confirm that the address code (Address ID) of each FFU is set correctly and can be successfully recognized and communicated by the central control system.
•  System integration debugging:
• Wind speed/air volume debugging: Use an anemometer to measure the wind speed of each FFU, and adjust it to the design value (such as 0.45m/s ± 0.05m/s) through the control system to ensure the uniformity of wind speed throughout the room.
• Group control function test: Test whether the centralized/decentralized control, group control, scheduled start stop, fault alarm (such as filter blockage alarm, motor fault alarm) and other functions of the system are normal.
• Differential Pressure Debugging: Coordinated debugging with the fresh air unit (MAU) and return air system to ensure that the pressure gradient in the room meets the design requirements.
•  Document handover: Provide complete installation records, wiring diagrams, FFU address tables, debugging reports, operation and maintenance manuals, and other documents.

• Planning preparation: Measure the flatness and strength of the ceiling, ensure the airtightness of the static pressure box, deliver in batches and store properly, conduct technical disclosure and create a sample area to create qualified conditions for installation and avoid rework.
•  Installation implementation: Handle with care, protect the filter, ensure installation sealing, no air leakage, correct polarity of power/communication lines, do a good job of dust protection for finished products, ensure installation quality, and protect core components.
•  Debugging and verification: Check the operation and communication of each unit, debug the uniformity of wind speed, test all group control functions, complete system linkage debugging, and ensure that the system operates according to its design functions.
• Finally, remember that large-scale FFU installation is a team effort, and a unified standard, strict process, and attention to detail attitude are the key to success. It is strongly recommended to have an experienced professional team carry out the construction and maintain close communication with FFU suppliers and control system integrators.