Cleanroom air shower - when is it worth it?
An air shower is an interlocked cabin at the cleanroom entrance that blows particles off people and goods with directed air jets. This guide explains when it is worth installing and how to size air velocity, nozzle layout and cycle time.
View air showersWhen is a cleanroom air shower worth installing?
An air shower makes sense when people or material carts move from a less clean area into a critical cleanroom and carry loose particles on clothing and surfaces. It supplements the gowning area and personnel airlock rather than replacing them. From ISO class 6 upward (ISO 5, ISO 4) it noticeably reduces particle ingress.
The benefit grows with personnel frequency and process criticality. In semiconductor, medical device and pharmaceutical manufacturing the air shower is often part of the airlock concept, whereas in simple ISO 8 environments good cleanroom garments and tacky mats are frequently enough.
How to transfer goods and carts into the cleanroom with low particle load.
Read the guideWhat air velocity do the nozzles need?
The decisive figure is the jet velocity at the nozzle. Particle release only becomes effective above about 20 m/s; common designs run at 20 to 25 m/s, and high-end systems reach up to 30 m/s at the nozzle opening. Too little velocity fails to detach particles, while too much only adds noise and energy use with no extra benefit.
The blown air is returned in recirculation mode through HEPA filters of class H13 or H14, so the detached particles are captured and do not re-enter the airflow. Only this keeps the cabin effective over many cycles.
How to arrange nozzles and cycle time?
The nozzles should reach the person from several sides and across the full body height. Adjustable nozzles on both side walls, optionally on the ceiling, have proven effective so that front, back and shoulders are all hit. The user turns slowly during the cycle so every surface is reached.
- Nozzles on both sides and height-adjustable to cover head to foot.
- Slight downward jet angle so particles are guided to the floor and extraction grille.
- Extraction in the lower part of the cabin to remove detached particles in an orderly way.
- Interlocked doors so no cross-draught arises during the cycle.
- For carts, wider cabins with extra nozzles at load height.
The cycle time controls how long the blowing lasts. Common values range from 10 to 30 seconds; shorter times raise throughput, longer ones improve particle removal. A compromise of about 15 to 20 seconds captures most loose particles without blocking personnel flow.
Frequently asked questions
Does an air shower replace cleanroom clothing?
No. It only removes loosely attached particles from the outside. Without suitable cleanroom garments, skin flakes and fibres still enter the room. The air shower is a supplement, not an alternative.
What air velocity is required?
About 20 to 25 m/s should be present at the nozzle. Particles only detach reliably from surfaces above roughly 20 m/s. Verify the value with an anemometer directly at the nozzle.
How long should a cycle last?
Typically 10 to 30 seconds, often around 15 to 20 seconds. The duration is a compromise between particle removal and personnel throughput and is matched to the traffic frequency.
Does every cleanroom need an air shower?
No. It is mainly worthwhile from ISO 6 classes upward and with high personnel frequency. In simple ISO 8 areas, cleanroom garments and tacky mats are often enough.
Looking for an air shower for your cleanroom?
We supply personnel and cargo air showers with HEPA H14 recirculation, adjustable nozzles and interlock - sized to your cleanroom class per ISO 14644-1.
HEPA filtered
Recirculation through H13 to H14 filters keeps particles captured.
Effectively sized
Nozzle velocity of 20-25 m/s for reliable particle release.
Verifiably tested
Air velocity and cycle documented and maintainable.
Expert advice
Cleanroom specialists support the sizing.