Cleanroom Construction: A Comprehensive Guide to Systems and Infrastructure
In precision manufacturing, tiny particles can make or break a product. Maintaining a sterile environment is often half the battle — cleanrooms are the solution.
For industries like semiconductors and pharmaceuticals, where even the smallest dust particle can compromise quality and performance, cleanrooms provide a controlled environment to manufacture reliable, high-quality products.
What is a Cleanroom?
Cleanrooms are highly controlled environments that manage airborne particles, temperature, humidity, airflow, and other contaminants.
Advanced air filtration systems and precise temperature and humidity control help prevent outside particles from disrupting manufacturing. Cleanrooms also regulate static electricity, vibration, and lighting to stabilize conditions.
They follow ISO 14644 standards and are classified by the number and size of particles permitted.
For example, an ISO 7 cleanroom allows 352,000 particles per cubic meter, while an ISO 8 cleanroom permits up to 3,520,000 particles per cubic meter. The fewer particles allowed, the cleaner the room.
Key Aspects of Cleanroom Construction
A lot goes into cleanroom construction. Every component must be carefully selected and installed to comply with stringent standards.
Enclosure & Interior Systems: Walls, Ceilings, and Flooring
The foundation of an effective cleanroom is its walls, ceilings, and flooring.
- Cleanroom Walls
Color-coated steel sheets (dual-material panels with rock wool, PU, or PIR insulation) or stainless steel sheets are used to create a seamless cleanroom wall system.
These materials are easily sanitized and chemically resistant, making them an ideal choice. They also comply with GMP and ISO 14644 standards to prevent dust from sticking to the surface.
- Ceiling System
Cleanroom ceilings are often made with an aluminum alloy frame with modular ceiling panels.
The modular design, which is easier to reconfigure, makes installing fan filter units (FFU), lighting, piping, and other equipment more convenient.
- Flooring System
There are a few options for cleanroom floors:
- Epoxy Flooring: Anti-static, durable, and easy to clean
- Conductive Vinyl Flooring: Superior anti-static capabilities
- Raised Floor (Perforated):For high-grade cleanrooms, allowing filtered air to return underneath the flooring
HVAC & Air Filtration
No cleanroom can function without these core components:
- HVAC Clean Air Conditioning System (Heating, Ventilation, and Air Conditioning)
The HVAC system is the lungs of the cleanroom. It’s responsible for providing a clean flow of purified air through:
- Supply Air System: FFUs or air handling units (AHU) help control airflow, temperature, and humidity.
- Return Air System: Air returns through return vents or raised floors. Higher-grade cleanrooms tend to use return air ducts or laminar flow return air walls.
- Exhaust System: Exhaust ducts and activated carbon filters are used in specific processes, like handling chemicals or solvents.
- Air Filtration System
HEPA or ULPA Filters play a critical role against airborne particles — HEPA catches 99.97% of particles at 0.3μm, and ULPA catches 99.999% of particles at 0.12μm. These high-performance filters provide precise environmental control, keeping contaminants that can damage sensitive products and manufacturing processes at bay.
FFUs are part of the air filtration system too. They provide a stable and clean airflow, particularly for ISO 1-6 cleanrooms. Air purification systems like molecular filters are also implemented to remove contamination.
Pressure Control & Environmental Monitoring
Precise control and continuous monitoring of other environmental factors are all parts of maintaining a stable environment.
- Differential Pressure Control
A differential pressure control system helps maintain the pressure difference between the inside and outside of a cleanroom. This is important for preventing contaminants from entering and hazardous materials from getting out.
A cleanroom usually maintains a positive pressure when the air pressure inside is higher than outside. Negative pressure designs, or when the air pressure outside is higher than inside, are used for special purposes, like biosafety laboratories.
- Environmental Monitoring System (EMS)
Manufacturers rely on the real-time data an EMS provides to monitor and maintain the cleanroom conditions.
An EMS monitors these key environmental factors:
- Particles: Measures the number of airborne particles.
- Temperature and Humidity: Maintains stable temperature and humidity levels.
- Pressure: Ensures proper airflow and prevents contamination influx.
- VOC/AMC Concentrations: Checks for chemical pollutants.
Electrical & Lighting Systems
Even electrical and lighting systems need to be precisely integrated into a cleanroom.
- Cleanroom Lighting
Energy efficiency and easy maintenance are key considerations when choosing cleanroom lighting.
Cleanroom-grade LED lighting prevents dust from accumulating and ensures the proper brightness, typically within 300-1000 Lux. Recessed lighting fixtures are commonly used to avoid the disruption of airflow.
- Electrostatic Discharge (ESD) Control
A cleanroom can have static electricity buildup. So, installing anti-static flooring, grounding cables, and static eliminators can prevent static electricity from affecting electronic manufacturing processes.
- Electrical & Control System
Cleanrooms have sensitive equipment that cannot withstand power fluctuations or outages. Uninterruptible power supply (UPS) systems provide a stable source of power.
Programmable logic controllers (PLC) control airflow speed, temperature and humidity, and pressure differences. This makes it easier to manage everything automatically and keep conditions consistent.
Access Control & Material Flow
Contamination prevention begins at the point of entry.
- Cleanroom Doors
Airtight doors are a must because they help maintain a clean environment. Automatic or interlock doors control personnel and materials access, ensuring a stable airflow and minimal contamination risks.
- Air Showers
Air showers remove any particles or dust on the personnel or materials before entering the cleanroom.
- Pass Boxes
For small material transfers, pass boxes minimize the need to open doors, reducing the risk of contamination.
- Material and Personnel Flow Design
The flow design is crucial for protecting cleanroom integrity. Both personnel and materials need to follow a specific sequence:
- Personnel Flow: Gowning room → buffer zone → cleanroom
- Material Flow: Material pre-processing area → buffer zone → clean area
- Gowning Room
The gowning room includes lockers, hand-washing facilities, and air showers to maximize cleanliness.
Cleanroom Supporting Equipment
Consider these supplementary equipment for an extra layer of protection against contaminants:
- Clean Benches
Clean benches provide a targeted, high-cleanliness space for precision electronics, optics, and pharmaceutical operations.
- Clean Booths
Clean booths rely on FFUs to maintain a clean environment. Their modular design enables quick construction and is suitable for semiconductors, optoelectronics, and precision electronics industries.
- Biosafety Cabinets
Fully enclosed biosafety cabinets are a great addition for biotechnology, medical, and laboratory operations, as they protect personnel from toxic biological contaminants.
- Cleanroom Garment Cabinets
Garment cabinets keep cleanroom garments clean and organized.
- Automatic Hand Washers & Dryers
Automatic hand washers and dryers are used for sanitation before entering the cleanroom. They effectively remove any dust or bacteria from your hands.
- Cleanroom Shoe Sole Cleaners
Shoes pick up a lot of dirt and debris, and a shoe sole cleaner solves that problem.
- Aseptic Material Transfer Carts with UPS
Transfer carts ensure that materials are not contaminated while they’re transported.
- Glove Boxes
Glove boxes are fully enclosed, airtight chambers that isolate and protect personnel or objects from harmful substances.
- Bag-In Bag-Out Filter Systems
Bag-in bag-out filter systems protect personnel from biohazards when doing routine HEPA or ULPA filter changes.
ACDT: Your Trusted Cleanroom Partner
From walls and flooring to HVAC and air filtration systems, every component must hold up its end in cleanroom construction.
You need equipment you can trust — and a partner you can trust.
With over 30 years of experience and 4000 clients worldwide, ACDT has proven expertise in manufacturing cleanroom equipment.
Our specialized knowledge extends to optoelectronics, semiconductor, pharmaceutical, and medical industries, allowing us to deliver tailored solutions for all.
Contact us today to discuss your cleanroom construction project.