Cleanrooms are environments specially designed to keep concentrations of airborne particles at or below certain thresholds. They are used for scientific research and for manufacturing delicate parts, such as electronic hardware.
Cleanroom HVAC systems are specially designed to keep the air in the space nearly sterile. Just as it’s important to choose the right cleanroom supplier to keep your facility well stocked, investing in the right HVAC system is essential for a viable cleanroom operation.
HVAC for cleanrooms are specially engineered systems that keep the space free of particulate matter, which can contaminate delicate parts or invalidate research results.
Cleanroom HVAC systems feature: • Temperature and humidity control • Increased air supply • Customized airflow patterns • High-efficiency filtration systems • Room pressurization
Cleanroom HVAC systems are carefully calibrated to ensure consistent temperature and humidity levels regardless of outside conditions.
This is vital for preventing growth of bacteria, viruses, and other pathogens. It’s also vital for preventing condensation, overheating, and other issues that might damage delicate components (for example, in a facility that manufactures integrated circuits).
Frequent air changes in a cleanroom: • Help prevent particulates and pathogens from settling on surfaces
• Keep air circulating evenly throughout the space • Help maintain optimal pressure
A home air conditioning system might change out the air of a given space 2-10 times an hour. Compare that to the typical cleanroom HVAC system, which changes out the air an average of 20-60 times an hour, but as much as 600 times an hour.1
The airflow patterns in a cleanroom prevent particulate matter from settling on surfaces. Airflow typically falls into one of three categories: • Unidirectional/laminar flow: This configuration uses air flow hoods that direct air streams downward in a straight path. They’re used in cleanrooms that are architecturally designed to minimize air turbulence. • Non-unidirectional/turbulent flow: This configuration uses turbulent airflow streams to remove particulates from the air.
• Mixed flow: This configuration use a mix of unidirectional and turbulent air streams in different parts of the cleanroom.
Filtration is by far the most important component of HVAC for cleanrooms. Cleanroom HVAC systems typically use either: • HEPA filters, which remove particulates as small as 0.3 microns with an efficiency rate of 99.97%. HEPA filters typically provide 80-100% ceiling coverage in cleanrooms.1 • ULPA filters, which are used for ultracleanrooms and remove 0.3-micron particles at a minimum efficiency of 99.999%.1
Pressure helps keep contaminants in or out. Cleanrooms can be positively or negatively pressurized. • Positive air pressure cleanrooms have higher pressure levels than the surrounding environment. They’re useful when keeping contaminants out is critical– for example, in hospitals that care for immunocompromised patients or facilities that manufacture microchips. • Negative air pressure cleanrooms have lower pressure levels than the surrounding environment. They’re used to keep contaminants contained within the given space, often in biochemical, pharmaceutical, and medical operations.
Designing a cleanroom HVAC system requires specialized skill and knowledge. Designers must understand airflow streams, temperature, humidity, and filtration requirements.
They also must understand applicable federal codes and standards and know how to use and install the required instrumentation and controls. If you’re planning a cleanroom installation, take the time to carefully research companies and choose an installer wisely—the viability of your operation depends on it.
Prudential Cleanroom Services (a division of Prudential Overall Supply) has been a trusted provider of cleanroom services and products for decades. PCS specializes in cleanroom garment processing services for aseptic, particulate, and ESD-controlled environments. All PCS Cleanroom Services Garment Processing Facilities are validated for sterile garment processing and have ISO 9001-certified quality management systems in place. Prudential also provides national cleanroom laundry and apparel services.
Learn more at www.prudentialuniforms.com/services/clea nroom/.
https://www.cedengineering.com/userfiles/HVAC%20Design%20for%20Cleanroom%20Facilities.pdf\
Summary
Prudential Cleanroom Services, one of the nation’s leading clean room suppliers, discusses why choosing the right HVAC system for your cleanroom is so important.