Air shower (room)

Air showers are specialized enclosed antechambers which are incorporated as entryways of cleanrooms and other controlled environments to reduce particle contamination. Air showers utilize high-pressure, HEPA- or ULPA-filtered air to remove dust, fibrous lint and other contaminants from personnel or object surfaces. The forceful "cleansing" of surfaces prior to entering clean environments reduces the number of airborne particulates introduced.

When properly incorporated into cleanroom design, air showers provide an ISO-classified transition vestibule to ensure the cleanliness of the classified cleanroom . Air showers are typically placed between a gowning area and cleanroom; after workers don appropriate garb and personal protective equipment, they enter the shower so that the pressurized air nozzles remove any residual particles from coveralls. Once the program cycle is complete, users exit out through a second door, into the cleanroom. Air showers (or air tunnels) may also be placed between cleanrooms of different ISO ratings.

Air showers are generally constructed from cleanroom-compatible steel or plastic materials and feature electronically-powered blowers, filters and high-pressure jet nozzles, the latter being incorporated into the walls and ceiling of the chamber. Air, at velocities of 3,000 to 7,000 feet-per-minute (FPM), continuously streams from the jet nozzles for 30-45 seconds, effectively removing loose particulate matter. Personnel inside the enclosure will lift their arms and turn their bodies for uniform exposure to the air streams, a procedure usually specified in . Air currents from the jets create shearing and flapping forces, which lift and remove contaminants from both flat surfaces and the creases of garments.HEPA filtration within the air shower is capable of removing 99.97% of particles greater than 0.3µm diameter.

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