In order to further reduce particle contamination in clean rooms and other controlled environments, such facilities may make use of air showers.
Air showers are enclosed, specialised chambers which are installed at entrances to clean rooms.
Air Showers Reduce Particle Contamination
Standard Air Showers make use of HEPA filters and forced airflow to scrub contaminants from gowned up personnel in order to significantly reduce particle contamination carried into the clean room by workers.
Air showers also provide an ISO-classified area which is most commonly located between the cleanroom and gowning area.
Once the operators have put on all the relevant personal protective equipment, they step into the shower so that any residual particles which may have been collected in the gowning area are removed by vigorous forced airflow movement within the air shower.
The air shower follows a programmed cycle and only once this cycle is complete may the operator step out of the air shower into the clean room.
Additionally, depending on the type of facility, air showers may be installed between clean rooms which have different ISO ratings.
The ISO rating refers to the level of cleanliness the room complies with, according to the size and quantity of particles per volume of air.
How Safe are Air Showers?
A common feature found in air showers are interlocking mechanisms which prevent both entrances or exits to be opened at the same time which would allow contaminated air from outside to enter the tightly controlled environment.
This means that operators are required to stay inside the shower chamber until the decontamination cycle is complete and the relevant door is automatically opened.
Therefore, emergency stops are a widely used safety feature for the unlikely event that something should go wrong during the shower cycle.
Air shower Features
Clean room compatible plastic / Stainless Steel or Powder coated steel construction.
Electronically powered blowers with high-pressure jet nozzles
Continuous streams of air at velocities of 3000 – 7000 feet per minute for a period of 30 – 45 seconds.
Air currents create flapping and shearing forces to lift loose contaminants from the creases of garments as well as flat surfaces
HEPA filtration inside the air shower
Air is continuously re-circulated using a closed loop system
Air contaminated with particles is drawn back to the blowers through low level washable pre-filters mounted inside the air-shower.
Air Shower Maintenance
Regular inspection of the electrical circuit is required to make sure the doors are correctly locked when closed and unlocked when the cycle is complete
Once installed, the air shower must not be moved. Moving the air shower will result in the deformation of the shower.
Regular pre-filter cleaning and/or replacement is required.
After replacing the HEPA filters, there must be no leakage in the frame. This can be tested using the DOP test method.
When replacing HEPA filters, instructions according to the original HEPA filter specifications must be strictly adhered to.
Vivid Air – Clean Room Equipment South Africa
We are manufacturers and suppliers of some of the highest quality clean room equipment in South Africa, including air showers and HEPA filters.
To find out more about air showers and other clean room equipment used to reduce particle contamination in controlled environments, contact us.