A cleanroom is a controlled environment specifically designed to minimize and control airborne contamination. It is crucial for manufacturing processes requiring high levels of cleanliness, such as electronics, pharmaceuticals, medical devices, food production, and scientific research. Various factors must be strictly regulated within a cleanroom to ensure compliance with established standards. In this article, we will explore the key controllable factors in a cleanroom.
Controllable Factors in a Cleanroom
1. Air Change Rate
The air change rate within a cleanroom significantly impacts air quality maintenance. Air circulation is regulated by HVAC (Heating, Ventilation, and Air Conditioning) systems and air filtration through HEPA (High Efficiency Particulate Air) or ULPA (Ultra Low Penetration Air) filters to remove microscopic particles. Proper air exchange prevents particle accumulation and ensures a clean environment.
ISO 5 or Class 100 cleanrooms require an air change rate of 240-600 times per hour.
ISO 7 or Class 10,000 cleanrooms have an air change rate of approximately 30-60 times per hour.
2. Particle and Dust Control
Cleanrooms enforce stringent control over airborne particle levels using standards such as ISO 14644-1 or GMP (Good Manufacturing Practice) as per PIC/S (Pharmaceutical Inspection Co-operation Scheme) guidelines. Particles originate from personnel, equipment, or manufacturing processes.
HEPA or ULPA filters effectively reduce particle levels.
Personnel movement should be minimized to prevent contamination.
Use low-dust materials, such as smooth surfaces and specialized cleanroom garments.
3. Temperature Control
Temperature regulation within a cleanroom is vital for both manufacturing processes and worker comfort. Typically, the temperature is maintained between 20-25°C to prevent overheating of machinery and ensure efficient operation.
High-precision environments, such as semiconductor manufacturing, may require tighter control at 22°C ± 1°C.
Dedicated air conditioning systems help maintain temperature stability.
4. Air Pressure Control
Air pressure is crucial in directing airflow and preventing contamination spread. There are two main types of pressure control:
Positive Pressure: Prevents external contaminated air from entering, used in pharmaceutical production, medical device manufacturing, and electronics industries.
Negative Pressure: Prevents hazardous substances or pathogens from escaping, used in research laboratories, chemical production, and containment areas for infectious diseases.
5. Relative Humidity Control
Humidity levels in a cleanroom affect machinery, materials, and personnel health. The optimal relative humidity range is 40%-60%.
Excessive humidity can cause machinery corrosion, material degradation, and mold growth.
Low humidity can lead to electrostatic discharge (ESD), which can damage electronic components and sensitive materials.
6. Lighting Control
Proper lighting enhances work efficiency and reduces errors. Typically, cleanrooms use lighting with a color temperature of 4000-5000K and an illumination level between 300-1000 lux, depending on the manufacturing process.
Dust-proof light fixtures prevent contamination buildup.
Non-glare lighting reduces eye strain and enhances productivity.
7. Noise Control
Noise levels in a cleanroom should be maintained within acceptable limits (generally not exceeding 60-65 dB) to ensure worker efficiency and reduce stress caused by machinery noise.
Controlling various factors in a cleanroom is essential for smooth operations, contamination prevention, and compliance with cleanliness standards. Whether it is air circulation, particle control, temperature, pressure, humidity, lighting, or noise, each factor plays a crucial role in maintaining product quality and ensuring personnel safety. Understanding and adhering to these control measures will enhance cleanroom efficiency and uphold the highest industry standards.
