Key Design Considerations for Cleanroom HVAC Systems

1.Filtration must meet standards: Adopt a three-stage filtration system (pre-filter + medium-efficiency filter + high-efficiency filter (HEPA)) according to cleanliness level (e.g., Class 10 - Class 300,000). The HEPA filter should be placed at the end of the air supply to intercept fine dust.

2.Ventilation requires careful attention: The higher the cleanliness level, the more frequent the ventilation (Class 10 ≥ 240 times/hour, Class 300,000 ≥ 20 times/hour). Areas with high dust generation should have more frequent ventilation and exhaust.

3.Precise temperature and humidity control: Generally, maintain 20-24℃ and 45%-65% humidity. For industries such as electronics and pharmaceuticals, fine-tune according to process requirements (e.g., 18-22℃ for electronics), with accuracy controlled within ±1℃ and ±5% RH.

4.Pressure differential to prevent contamination: High-cleanliness areas should have a positive pressure ≥10Pa higher than low-cleanliness areas. Contaminated areas (e.g., weighing rooms) should have negative pressure and buffer rooms to prevent air turbulence.

5.Reasonable airflow: Use unidirectional flow (uniform airflow) in high-cleanliness areas and turbulent flow (mixing and diluting contaminants) in ordinary areas. Avoid directing air vents towards equipment or people to prevent dead zones.

6.Energy saving and cost reduction: Allocate fresh air only as needed (avoid waste), install heat recovery devices, use variable frequency fans (reducing speed under low load), and implement zoned temperature and humidity control for different areas.

7.Easy-to-clean materials: Choose stainless steel/galvanized steel for ducts and equipment (smooth and dust-free), ensure good sealing at connections to minimize air leakage, and provide access ports for easy maintenance.

8.Disinfection + antibacterial: In the pharmaceutical/food industries, add ultraviolet/ozone disinfection. Insulate equipment and ducts to prevent condensation, and drain condensate promptly to prevent bacterial growth.

9.Essential monitoring: Monitor cleanliness, temperature, humidity, and pressure differential in real time. Issue alarms for abnormalities, and retain traceable data (compliant with industry standards).