A Guide to Cleanroom Equipment and Sterile Environments

Air-Treatment System Equipment

Fresh-air filter box: Provides preliminary filtration of outdoor air entering the cleanroom, removing larger dust particles and other contaminants and reducing the load on downstream air-treatment equipment.

Central clean-air conditioning system: Normally includes primary-, medium-, and high-efficiency filtration stages. These successively remove larger dust, fine particles, and still smaller contaminants, ensuring that supply air reaches the required cleanliness level. The system also controls workshop temperature and humidity.

HEPA supply-air outlet: This assembly normally consists of a plenum box, HEPA filter, aluminum-alloy diffuser, and standard flange connection. It distributes HEPA-filtered clean air evenly throughout the cleanroom and helps maintain the required indoor cleanliness.

Fan filter unit: A fan draws air in from the top. The air passes through primary- and high-efficiency filters and is discharged at a precisely controlled velocity. Fan filter units are commonly installed with ceiling grids to create cleanroom environments of different classes. Their continuous circulation and purification of airflow maintains indoor cleanliness.

Personnel and Material Decontamination Equipment

Air shower: This is an important passage for personnel entering a clean area. After a person enters and closes the outer door, the fan draws in air and passes it through primary- and high-efficiency filters. Rotating nozzles then direct high-velocity clean air over the person's clothing to dislodge contaminants. Part of the air is recirculated through the filters. The person can enter the clean area after the cleaning cycle is complete.

Cargo air shower: This device cleans goods before they enter a clean area and works on the same principle as a personnel air shower. After the goods enter and the outer door closes, the fan starts and filtered air forms a clean flow. Multi-angle nozzles blow contaminants from the surfaces of the goods. Dislodged dust settles, is filtered, and the air recirculates. After decontamination, the goods can enter the clean area.

Pass box: This is mainly used to transfer small items between a clean area and a non-clean area or between two cleanrooms. An electronically interlocked pass box uses an integrated circuit or similar control to prevent both doors from opening at the same time. A self-cleaning pass box contains a fan and HEPA filter that purify the items. Pass boxes reduce the number of times cleanroom doors must be opened and lower the risk of contamination.

Local Purification Equipment

Laminar-flow hood: This unit provides a localized, highly clean environment. Its main components include an enclosure, fan, primary air filter, HEPA filter, damping layer, and lighting. A hood can be used alone, or several units can be connected to create a strip-shaped clean zone. It is suitable for local operations requiring extremely high cleanliness.

Clean bench: This unit maintains a localized area of high cleanliness over a work surface. Clean benches are available with vertical or horizontal laminar airflow. Their main components include a pre-filter, HEPA filter, and fan assembly. They provide a sterile, dust-free local environment for laboratory and production work.

Clean booth: This structure can be assembled quickly. Fan filter units continuously deliver clean airflow into the enclosed area, creating a localized workspace with high cleanliness. Clean booths are easy to install and highly flexible.

Other Supporting Equipment

Air-disinfection equipment: Ultraviolet disinfection units, ozone generators, and similar devices kill airborne bacteria, viruses, and other microorganisms. They help prevent microbial transmission and maintain sterile workshop conditions.

Humidification equipment: Devices such as spray-nozzle humidifiers and high-pressure atomizing humidifiers maintain appropriate workshop humidity. They prevent static electricity caused by excessively dry air, reducing electrostatic dust attraction and related safety hazards. Proper humidity control can also inhibit bacterial growth.

Airborne-particle counter: This instrument measures the number and size distribution of airborne particles in the cleanroom. It provides real-time monitoring of workshop cleanliness so that problems can be identified and corrected promptly.