Air Shower Frequently Asked Questions
What is an air shower?
An air shower is a self-contained enclosure that uses high velocity jets of HEPA filtered air to help decontaminate personnel and equipment prior to entering or exiting a controlled environment. The inside of the airshower is lined with multiple evenly distributed nozzles, pointed at various angles to optimize the air scrubbing process. The nozzles shoot concentrated streams of class 100 micro-filtered air to shake off and wash away loose particles and other contaminants clinging to the surface of personnel or equipment.
Operating as a closed-loop system, the particle-laden air is vacuumed out through exit vents along the bottom of the air shower. The air passes through pre-filters to capture larger particles before being pushed by the fan blower through HEPA or ULPA filters to capture remaining smaller particle contaminants. The pressurized filtered air then recirculates through the nozzles to continue the cleaning process.
Read more about air shower designs and applications.
What are some common air shower applications?
Decontamination air showers are used across many industries in facilities with different policies and cleanliness requirements. The most common industries include semiconductor, pharmaceutical, biological, industrial, and food/beverage.
In most cases, air showers are used to protect sensitive products/procedures inside a controlled environment, such as a cleanroom, from microscopic contaminants carried in by personnel. For cleanroom or lab applications, most facilities place an air shower at the entrance to a gowning room to reduce contaminants carried or generated by street clothes, prior to garbing with cleanroom apparel. These contaminants include fine particles such as dust that can ruin sensitive electronics, and also biological contaminants such as infectious fungus spores that can ruin sensitive plant crops or other cell cultures. Other facilities position air showers between the gowning area and the cleanroom, for workers to enter after they complete the garbing process. Cleanroom air showers and tunnels are also used to decontaminate equipment and other bulky materials (such as carts or loaded pallets) prior to entering a cleanroom.
For manufacturing facilities or construction areas with excessive hazardous metallic or organic dusts (for example lead, silica, asbestos, or wood dust), decontamination air showers can be used at exits to remove the microscopic particles from personnel or equipment. This helps contain the dangerous dusts produced in the manufacturing area and protect people outside manufacturing from harmful exposure that can cause serious if not fatal diseases.
What are the available air shower designs and configurations?
Terra offers standard cleanroom air shower and tunnel configurations plus countless customizable options for any application. The most popular and economical air shower design is the standard 2 door straight configuration, with the blower module mounted on-top of the enclosure.
Below is a list of common configurations and options. Call or chat with a product specialist to find the optimal solution for your unique requirements:
- Custom floor plans, including 90º turns and U-shaped chambers (see examples below)
- 3-door configurations to connect multiple rooms
- Low profile air shower designs with side-mounted blowers for ceilings as low as 96"
- Disassembled knock-down air shower configurations for easier shipping and transfer through space-restricted areas like small doorways or narrow hallways
- All-stainless steel air shower designs (chamber, doors, nozzles) for aseptic applications requiring frequent wipe downs
- Air shower pass through designs for transferring carts and other smaller equipment.
- Third-party UL or ETL safety certification for high voltage equipment
- Hygienic hands-free automatic doors
- Electronic interlocking and connection to building management system (BMS) for remote control
- Keycard readers or hands-free iris scanners for secure access
- ADA compliant air showers for wheelchair access
- Explosion-proof air shower designs for facilities with flammable substances
- ESD-safe ionizers are ideal for static sensitive applications and help more effectively dislodge particles attached by electrical forces such as static cling.
- Raised flooring to optimize laminar flow and more effectively sweep away loose contaminants
- Bumpers mounted on the interior walls to protect nozzles from carts
- Mobile air shower designs on a raised pallet can be quickly moved via forklift and re-installed where it's needed.
What are the benefits of UL-listed or ETL-listed air showers?
Terra Universal offers UL-listed and ETL-listed air showers for third party safety certification.These listings help meet municipal and other permitting requirements that may apply while ensuring the safety and integrity of high voltage electrical components.
Both are certified by OSHA as nationally recognized testing labs (NRTL) that test to nationally accepted safety standards. ETL can offer a quicker turnaround time for highly custom projects with short timelines. The NRTL status tells all customers that the testing services performed by these third party companies are reliable and legally binding throughout the United States. ETL,originally known as Edison Testing Laboratories, is an old, respected, nationwide testing group with credibility equal to UL or CSA.
How are air showers shipped?
Terra offers two shipping options:
- Air showers can be pre-installed at Terra, and then partially disassembled to ship out as multiple sub-assemblies, where the blower modules are separated from the rest of the pre-installed enclosure. These sub-assemblies are typically shipped on a flatbed truck and require a forklift to offload and re-assemble the air shower at the install site. This method saves assembly time at the install site.
- Air showers can be shipped out fully disassembled in a "knock-down" design for easier shipping as well as transport through space-restricted areas (narrow entries for example) to reach the install site. This method also requires a forklift to offload the equipment from the truck.
What control settings are available on the air shower’s PLC?
All of Terra’s air showers feature a fully customizable and easy-to-use touch-screen PLC. This microprocessor control comes programmed with the ability to:
- Adjust cycle operation times, entrance/exit delays, and when the lights turn on/off
- Measure filter back pressure and adjust setpoint for filter replacement
- Reverse the function of the entrance and exit doors at the touch of a button
- Count total number of cycles and total run time
The control panel can be easily programmed for other unique requirements such as custom interlocking sequences and connection to building management systems (BMS).
When does the cleanroom air shower’s HEPA filter need to be replaced?
The frequency at which the air shower HEPA filter needs to be replaced varies depending on several factors such as total operation time, quality of ambient air (dirty or humid ambient air will shorten the life of the filter), and maintenance of air shower prefilters.
Under average conditions, Terra recommends replacing HEPA filters every 2-3 years to avoid unexpected maintenance delays. Below are a few methods to determine when to replace the HEPA filter. It is important to note air showers use one HEPA filter per blower. Thus larger air shower systems may have multiple HEPA filters (one for each blower).
The control panel includes the ability to measure filter back pressure and alarm for filter replacement when the backpressure reaches the user defined setpoint. The control panel also includes a "run times" feature where personnel can keep track of how much air shower operation time and cycles have elapsed to help in setting up a filter replacement maintenance protocol.Lastly, it is recommended to periodically monitor the air velocity at the nozzles with an air velocity meter. The air velocity will initially average up to about 8,000 FPM, measured at each air nozzle. When the readings drop to below 80% of the initial value, the corresponding HEPA filter is approaching the end of its useful service life and is recommended to be replaced.
What is the air flow velocity inside the air shower?
When the shower cycle commences, pressurized air streams from adjustable nozzles at a velocity of up to 8,000 feet per minute (41 meters per second). This ensures the necessary efficient scrubbing action to remove particulate matter.
How can you rate the efficacy of your air shower?
You can rate the efficacy of the air shower by measuring the air flow velocity at each nozzle. Each nozzle is designed to provide up to 8,000 feet per minute of air flow. If the measured velocities fall significantly short of 8,000 feet per minute, check whether the HEPA filters need to be replaced.
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