An air shower is a chamber that blows high pressured air on an individual before he or she enters a controlled area. The air is forced at high speed through nozzles that are aimed at the individual so that contaminants are knocked off. The air is then cycled through prefilters and then through a high efficiency particulate air (HEPA) filter or an ultra low particulate air (ULTA) filter. The HEPA filter is able to remove 99.99% of particulates up to 0.3 microns in size, and the ULTA filter is able to remove 99.999% of particulates up to 0.12 microns. After being filtered, the air is sent back into the air shower to continue the process.
There are three types of air showers that may be available: the one-way; the two-way, one-way; and the two-way. With a two-way operation, the air shower activates when a person enters the controlled area room and when he exits it. With the two-way, one-way air shower system, the shower is activated only when a person goes into the controlled area. This allows a person coming from the controlled area room to exit through the chamber without having to endure the showering process.
With a one-way air shower, a person can use the chamber only to enter the controlled area. When the shower is not in use, the entrance door is unlocked. After a person enters, the door locks and the shower activates. Once the cleaning process is finished, the exit door unlocks, allowing the person to walk into the controlled area. After the person leaves, the exit door locks and the entrance door unlocks, allowing another person to enter.
The effectiveness of an air shower depends on many factors, including the size of the shower, the type of contaminants being removed, and how the individual behaves within the shower. In order for the air shower to work efficiently, an individual must usually stand in the center of the chamber with his hands above his head and turn 360° while the air is blowing. The nozzles should also be positioned so that the air can clean the person effectively. In addition, the duration of the shower should be long enough to remove the contaminant. After the process is finished, the individual should also wait a certain amount of time before going into the controlled area in order to allow the air shower to remove any contaminant that settle.