Contamination control technology is vital to research and development and manufacturing environments across virtually every industry. The emergence of microscopic contamination control enabled the creation of cleanrooms and air showers. The cleanroom air shower separates the outside environment from the entry to the cleanroom with a space bordered by interlocking doors.
Once inside, strategically located nozzles blow air through HEPA filters to loosen debris, particulates, and contaminants from the cleanroom apparel. The air filtration system vacuums the air from the chamber and recycles it after removing all particulates. This process ensures that any potential contaminants on clothing are not carried into the cleanroom.
Air Showers For Contamination Control
Air showers play a critical role in maintaining cleanroom integrity by removing loose contaminating particles from people and products before they enter the room.
Cleanroom air showers function as an entry system. The cleanroom entry system allows for the proper class identification and procedures for dressing and storing garments. At a minimum, the isolated air shower contains a blower and motor, HEPA/ULPA filtration, a recirculating exhaust system, and interlocking doors. However, the design could incorporate additional features, functions, and benefits, depending on the intended use.
The primary features of a properly designed air shower include:
Cycle time: The most crucial determinant of the shower’s effectiveness is the time it takes to remove contamination completely.
Dwell time: Dwell time is the period between the end of the cycle and opening the door. It ensures that the removed contaminants settle at the end of the process to prevent them from being swept into the cleanroom when the doors open.
Filtration: Filtration is critical to remove particulates from the cleanroom apparel and extract them from the environment before allowing the worker to enter the cleanroom.
Protocol: Proper protocol ensures maximum efficacy of the air shower. Best practices, such as placing hands on the head while rotating 360°, allows for thorough contamination removal.
Points of impact: Airflow from nozzles distributed across the walls and ceiling hit multiple points of impact. The diffuse contact creates a pulsating effect on the garments that dislodges the particulates.