Hello everyone, this is Baihong Purification.In this issue, we will discuss the key elements for achieving cleanliness in cleanroom construction.
1.Airflow organization design for cleanroom construction
The airflow organization in a clean room differs from that in conventional air-conditioned spaces. Its core lies in preferentially delivering the cleanest air to the operation area to minimize contamination of the processed materials. The design must adhere to the following principles:
（1）Reduce eddy currents and prevent contaminants from non-working areas from entering the working area
（2）Prevent dust from re-entrainment and reduce the risk of workpiece contamination
（3）Ensure that the airflow in the work area is uniform and the wind speed meets the process and hygiene standards
（4）Enable the return air to effectively carry away suspended particles
（5）According to the difference in cleanliness levels, corresponding air supply and return modes need to be adopted.
2. Guarantee of supply air cleanliness
The core of ensuring the cleanliness of supply air lies in the performance and installation quality of the terminal filters. High-efficiency particulate air (HEPA) filters or sub-HEPA filters are commonly used, and the selection criteria need to be comprehensively considered:
（1）Environmental pollutant concentration (higher-grade filters are required for highly polluted environments)
（2）Indoor exhaust air ratio (higher filtration level is required when the exhaust air volume is large)
（3）The criticality of the clean room (safety factors need to be increased for important areas)
（4）For cleanrooms with control requirements for 0.1μm particles, regardless of the concentration, Grade D filters should be selected. The actual selection requires a comprehensive evaluation of the cleanroom characteristics, filter performance, and overall system configuration.
