Air Showers for Cleanrooms

What Is an Air Shower?

An air shower is a self-contained decontamination chamber equipped with high-pressure air nozzles, HEPA filtration, and an interlocking door system that prevents both doors from opening simultaneously.

Its purpose is to remove particles, dust, and microorganisms from personnel or equipment surfaces prior to entering the cleanroom.
Typically, personnel enter the air shower directly from the gowning area. Once inside, a preprogrammed decontamination cycle begins automatically.
After completion, the person exits through the second door into the controlled cleanroom environment, significantly reducing cross-contamination risks.

How an Air Shower Works

An air shower operates using high-velocity filtered air jets directed through nozzles located on the walls and ceiling.
These air jets blow at speeds between 50–65 m/s (10,000–12,500 ft/min) for 20–30 seconds, efficiently dislodging contaminants from garments and surfaces.

The air passes through a HEPA (High Efficiency Particulate Air) filtration system that removes 99.97% of particles ≥0.3 microns, ensuring compliance with ISO 7 cleanliness levels according to ISO 14644.

Air within the system is continuously recirculated:

1.- Filtered air is expelled through the high-pressure nozzles.

2.- Contaminated air is captured and pulled into the return ducts.

3.- The air passes back through the HEPA filters before being reused.

This closed-loop recirculation maintains a consistent supply of clean air and a uniform decontamination process.

Types of Air Showers

Air showers are available in different configurations depending on the number of users and required throughput:

Chamber-Type Air Showers

Compact cabins designed for one or two users at a time. Ideal for low-traffic areas where strict individual decontamination is required.

Tunnel-Type Air Showers

Extended air tunnels designed for high-volume personnel flow. Multiple users can walk through simultaneously while being exposed to air jets from all sides.
A tunnel should typically be at least 8 meters (26 ft) long to achieve an effective 20–30 second cleaning cycle.

Both configurations can be customized in size, airflow rate, and materials depending on your cleanroom classification and process requirements.

Key Features of a High-Performance Air Shower

An effective air shower must combine powerful airflow, efficient filtration, and hygienic construction.

1. Air Velocity and Coverage

The air velocity at the nozzles should range from 50 to 65 m/s (10,000–12,500 ft/min), with approximately 20 nozzles per user spaced at 10 cm (4") to ensure full-body coverage during decontamination.

2. Airflow Capacity

A high-efficiency system maintains a flow rate of 1.5 m³/min (50 ft³/min) per nozzle, ensuring the proper air volume and pressure for complete particle removal.

3. Multi-Stage Filtration System

Air showers integrate a three-stage filtration system:

- MERV 8 Prefilter: captures large particles and extends filter life.

- MERV 15 Filter: provides medium-efficiency filtration.

- HEPA Filter: delivers 99.97% efficiency for particles ≥0.3 µm.

This setup guarantees ISO 7 air cleanliness and minimizes maintenance downtime.

4. Hygienic and Durable Design

Constructed from stainless steel, powder-coated steel, or aluminum, the structure is smooth, corrosion-resistant, and easy to clean.
All interior surfaces are flush and free of horizontal edges, preventing dust accumulation.
Each system includes interlocking automatic doors, programmable control panels, and an emergency stop button for operator safety.

Safe Use of an Air Shower

To ensure proper operation and personnel safety:

- Doors are interlocked, preventing both from opening simultaneously during a cleaning cycle.

- The decontamination cycle must complete before the exit door unlocks.

- The emergency button allows immediate door release in case of an incident.

- In a power outage, the doors automatically unlock to allow safe evacuation.

These safety mechanisms ensure reliable operation while maintaining cleanroom integrity.

Benefits of Air Showers

- Full compliance with ISO 14644 and GMP standards.

- Significant reduction of airborne contaminants entering clean areas.

- Enhanced process safety and protection of critical environments.

- Energy efficiency through air recirculation and smart system design.

- Custom engineering for specific space, capacity, and ISO requirements.

The system is designed for maximum durability, precision, and compliance, ensuring long-term reliability in your contamination control process.

Conclusion

An air shower is a critical barrier between uncontrolled and controlled environments, preventing contamination and preserving cleanroom performance.
Its design, airflow velocity, and filtration quality directly influence the cleanliness and safety of your production area.

At Star Filters, we provide custom-built air shower systems with HEPA-certified filtration, modular construction, and programmable control systems, meeting the strictest international standards for cleanroom applications.
We serve pharmaceutical, biotechnology, electronics, and precision manufacturing industries where air quality equals product quality.