Home › Resources › CAP-701 Air Showers FAQ

CAP-701 Air Showers Frequently Asked Questions

  Air showers can greatly enhance your cleanroom’s performance by removing surface contamination from clothing and cleanroom garments. Gowning/changing room areas are the interface between a dirty “street clothes” environment and a clean room environment. Unfortunately, the changing or gowning process itself releases contaminants from street clothes that can settle onto the “clean” garments. Air showers blow off and remove much of this contamination preventing it from entering the clean space. For more specific information on different air shower applications, see the Engineers Guide to Air Showers section on the website.

[ top ]How does an Air Shower Work?

The air shower produces high pressure air, filters this air through a HEPA/ULPA filter, then flows the air through adjustable nozzles which exit at a high velocity, so air is directed towards the individuals waiting to be cleaned. This high-velocity air removes surface particles and also “flaps” the garments to dislodge more firmly attached particles. After cleaning, the air is re-circulated back to the high-pressure blower, where it is prefiltered, then HEPA/ULPA filtered and then ducted back to the adjustable high-velocity cleaning nozzles. The air shower utilizes an adjustable microprocessor controller to allow easy on-site adjustment of the cleaning cycle time and other critical process controls.

[ top ]How does Garment Type Influence Cleaning Effectiveness?

The cleaning effectiveness of the air shower is affected by the type of garments, the size, shape and type of contamination. Large light particles such as lint, hair, dander, and skin flakes are the easiest to remove. Particulate contamination adheres to garments in two basic ways: Either by mechanical entrapment or by an electrical attraction.
Mechanical bonds between the garment and particulate contamination are reduced when smooth surface garments are utilized. These include “cleanroom-designed” garments and those made from synthetic materials such as Tyvex, Gortex, polyester, and nylon – to name a few. These materials are low-shedding and minimize the mechanical bond, making it easier to blow the surface contamination off the garments.
Natural fibers, such as cotton, tend to shed particles and their surface finishes tend to have a higher mechanical bond with particles, making them harder to clean. Synthetic garments can develop a static charge. This charge can “hold” particles to the surface of a garment. To help reduce this charge, garments can be laundered with an “anti-static” agent in the final rinse. This will help reduce the level of static charge on the garments, allowing particles to be more readily removed. Some garments are available with special built-in conductive fibers that can assist in keeping the surface charge to a minimum. Consult your garment supplier for details.
Point Ionization (static neutralization) can be installed on the inside walls to dissipate some of the charge on the garments, helping to reduce the holding charge (force) of the garment, making it easier for the air to blow the particles off. In many cleanroom applications, much of the contamination in the room is carried in on the garments of the individuals working within the room. Typically they bring it to the most critical area.
Without using an air shower, individuals are often cleaner when they leave the clean space because a large portion of the contamination they had on their garments will have fallen off within the clean space. Using an air shower is an effective way to remove much of the contamination that would otherwise come off within the clean space.

[ top ]What makes the CAP701 Air Shower Superior?

An air shower in many ways can be compared to vacuum cleaner. They are available in a variety of sizes, capacities and features; some work very well while others just seem to make noise. To be effective, they need to have high cleaning force and power.

1. Superior Performance

A good vacuum cleaner has high suction and airflow to pick up dirt. A small vacuum with low suction and airflow does little more than pick up a few crumbs. The same can be said for air showers. Some air showers (not made by Clean Air Products) have a small blower/motor, low airflow and low pressure. These under-powered devices give air showers a bad name. The CAP701 air shower has a high velocity and a large air volume rate for fast, efficient cleaning. The Clean Air Products’ CAP701 air showers offer the highest velocities combined with a large airflow rate to provide an air shower that quickly and efficiently cleans particulates from the surface of clean room garments.

2. Superior Construction Materials

The CAP701 air shower is constructed of an all-metal, painted steel shell with no wood or plastic laminate and is entirely silicone free. The standard shower has a 16-gage steel shell, heavy-duty glass door and door closer. The shell and concealed air ducts are finished with a white powder coat paint which provides a strong, durable cleanroom-compatible finish. The all-steel shell design will stand up to the rigors of shipping, installation, use, and the occasional abuse of a high-traffic entry system. While we don’t recommend it, you could hit the metal shell of the air shower with a hammer. It may dent or scratch the paint, but you would not break the cabinet as you would with laminated types of construction.
The steel construction also reduces the chances of biological growth and contamination caused by systems using laminated particle board in the construction. Laminated particle board construction is fine for a simple table, but not for an important piece of equipment that is being integrated into your cleanroom system.
NOTE: A typical laminated particle board air shower has the plastic laminate on the outside – but often the interior concealed air ducts are just painted over the raw particle board – leaving a rough surface finish that harbors dirt and biological contamination. As the particle board ages and deteriorates, parts will flake off, becoming another source of contamination. All-metal (painted steel or stainless steel) air showers are the best type of air shower to purchase.

3. Superior Service Access

Service to the mechanical equipment, blower, motor, HEPA filter and prefilter is easily done from the inside of the air shower through a hinged access panel located in the interior ceiling of the air shower. This is desirable because you don’t have to penetrate the clean room ceiling surrounding the air shower for maintenance. Often the area around the air shower is not accessible because of ceiling filters, lights, ducts, pipes, walls or other equipment. Exterior-mounted service panels would make maintenance difficult or impossible in those cases. The unit’s electrical control panel is conveniently mounted on the outside of the air shower above one of the entrances (see the website for details), and is serviced from outside the air shower.

[ top ]What are the Different Types of Air Shower Designs?

Straight Thru Air Showers

The entry door and exit door are straight across from one another. This is the most common type of air shower.

90-Degree Air Showers

The air shower can be provided with the doors in a 90-degree configuration for those applications where a Straight Thru path will not work.

3-Door Air Showers

This air shower has three doors. The typical configuration is one
entrance door and two doors exiting to two different cleanrooms.

Tunnel Air Showers

Two or more air showers can be combined to form a longer unit. By adding complete sections, an efficient arrangement for the nozzles will be maintained. These tunnels can be used for “large batch” cleaning – if a large number of people will enter and exit as a group – or for “continuous flow” cleaning – where the showering time is determined by how long it takes to walk the length of the tunnel. Both 90-degree and straight-through air showers can be combined to form the tunnel configuration. NOTE: The cost for additional sections is lower than the basic unit, because the cost of the doors and electrical control is covered by the first unit – and additional units don’t need those items.

Low Profile Air Showers

The CAP701LP (low-profile) model has an overall assembled height of 95 inches. The unit has the blower assembly, HEPA filter, and electrical components mounted on the side to permit the lower height. It can be assembled in a space 96 inches high, making it ideal for retrofits or areas where penetrating the ceiling is undesirable. The unit is shipped disassembled to the point that all parts will fit through a standard doorway. Service access to the blower assembly, filters, and electrical components is through two doors on each end of the unit. This is standard. Note: When installing the Low Profile unit, it must stick through the wall so that the end access doors are available to service the blower and filters.

Cart/Part Air Showers

Parts-cleaning air showers are available in a variety of sizes, shapes and configurations. They are available to be used with carts, conveyors, pallets and continuous-part operations. This style of air shower can use swing doors, vertical-sliding, horizontal sliding, or no doors at all. Please consult the factory with details of your specific application.

Wall Mount Pass Thru Air Showers

These are similar to the Cart/Part Air Showers, but they are smaller and mount off the floor.

Decontamination Air Showers for Leaving a Controlled Space

These air showers are similar to the standard air shower except for a few common options:
  1. They typically do not have door interlocks.
  2. They have wall start switches.
  3. They often are not walk through – they have only one door. The end without the door is put against an existing wall so you enter and exit through the same door.
  4. Lower side-wall prefilters – unless the raised floor option is ordered.
  5. A respirator is used for any toxic materials being cleaned off. NOTE: A respirator is only required for the decontamination of toxic materials.
  6. Often a compressed-air fitting is installed to allow additional blow-off during cleaning – or to blow air into the outer coverall to “blow it up” so it is easier to clean.

ADA Compliant Air Showers

Sometimes the air shower must comply with the Americans with Disabilities Act (ADA). This requires the inside of the air shower to be larger so that an individual in a wheelchair can turn around inside the air shower. See the ADA Compliant Air Showers section on the website for sizes and details. Optional automatic door openers may also be needed. Consult your local code officials to see what is required for your application.

[ top ]How is the Air Shower Typically Shipped?

The air shower can be shipped fully assembled (on its side on the skid) or knocked down with the wall panels off from the upper blower cabinet – allowing the components of the air shower to fit through a 3 ft. x 7 ft. door opening when removed from the shipping skid. If the components are required to fit through a 3 ft. x 7 ft. door, this should be specifically requested on the quote and order. 
Note: If the ceiling purge option is ordered, the blower cabinet will be too large to fit through a standard 3 ft. x 7ft. door. The skid weight for a single CAP701-4954 standard air shower is approximately 1500 lb. The size of the skid when fully assembled is about 68 in. W x 126 in. L x 60 in. H. The skid size when the unit is shipped knocked down is 68 in. W x 144 in. L x 60 in. H. These are for reference only – the actual skid measurements will depend on the size of the air shower ordered, options, and if multiple units are shipped together.

[ top ]What are the Typical Installation Configurations?

The air shower can be installed so the entire air shower sticks through the wall, with space around the air shower. This space is filled with an optional trim angle. The shower can also butt up against a wall with an opening large enough for the door and related end-mounted hardware (approximately 48 in. x 90 in.). Please request a quote before planning cut-outs – different configurations and sizes may require different cut-out sizes. When the unit is butting against the wall, the contact point between the air shower and the framed opening is typically caulked or a small trim molding is applied. The exterior of the air shower would also have a trim angle.

[ top ]What is the Typical Installation Process?

When shipped fully assembled on its side, the weight for a CAP701-4954 is approximately 1300 lb. Two eye bolts located on the top of the air shower can be used to assist in lifting. After standing up the unit, it is then moved into position and leveled using shim stock and is anchored to the floor (anchors to be provided by the installer).
When the unit is shipping knocked-down, the CAP701-4954 air shower upper blower cabinet is 650 lbs. The wall panels are 250 lbs. NOTE: The knocked-down air shower needs room on the sides of the unit during the assembly process to install the 3/8 in. mounting bolts. To assemble the unit, the blower section is taken off the skid and raised into position. The two wall sections are then bolted from the outside onto the upper blower housing. At this point, the assembly is self-supported. The doors are attached, power is connected, and the unit is ready to run. Assembly is fast and uncomplicated. Each unit is shipped with a detailed manual. We do recommend using mechanical lifts to assist in the assembly process. Once the unit is assembled, no space is required on the sides of the unit. After the unit is assembled, moved into place, and the mounting is complete:
  1. An electrician needs to connect power to the air shower, start the unit, and check blower rotation.
  2. A sprinkler contractor needs to install the sprinkler.
  3. The installer touches up the paint (if needed)
  4. The installer adjusts the doors and door closers (if needed)
  5. The installer adjusts the magnetic door interlocks (if needed)
  6. The installer confirms that high-velocity air is flowing out the nozzles at approximately 90 MPH. If the blower is running backwards, air will still come out of the nozzles – but only at about 15 MPH. Blower rotation can also be confirmed by looking at the blower itself.
  7. The installer cleans the inside of the air shower and the interior floor space.
  8. The installer seals any seams with caulk (provided by the installer) as required.

[ top ]What are the Standard CAP701KD Air Shower Features?

Shell Construction

The CAP701 air shower is constructed of an all-metal, painted steel shell with no wood or plastic laminate and is entirely silicone free. The shell and concealed air ducts are finished with a white powder coat paint which provides a strong, durable, cleanroom-compatible finish.

Service Access

Service to the mechanical equipment, blower, motor, HEPA filter and prefilter is easily done from the inside of the air shower through a hinged access panel located in the interior ceiling of the air shower. The unit’s electrical control panel is conveniently mounted on the outside of the air shower above one of the entrance doors and is serviced from outside the air shower.

Doors

The doors have heavy-duty aluminum frames and full length clear safety glass viewing windows. The door assembly has a clear anodized finish on both the door and door frame. Each door is furnished with heavy-duty door hinges and a door closer.

Electrical Supply

The standard requirement for the air shower is a 208 V 60 Hz, three-phase, four-wire. Typical units are 13.6 FLA per blower section. Multiple sections would increase the total power required. Motor starters and disconnects on the main control panel are provided as standard. They are mounted above one of the doors going into the air shower as standard. Local code or installation conditions may require an additional disconnect switch.

Electrical Control Panel

There is a gray painted steel main electrical control panel mounted above one door on the exterior of the cabinet. This control panel includes the starter, thermal overloads, fuses, relays, power shut off, and a microprocessor controller (PLC). The PLC is used for timing the cleaning cycle, controlling the optional interlocking of the doors, and starting of the air shower.

Microprocessor Controller

A microprocessor controls the starting of the air shower so that the unit will only start when people are going through in one direction. On applications where there is bi-directional travel through the air shower (people using the shower to both enter and exit the cleanroom) – the air shower only starts when people are going into the cleanroom, not when they are leaving. The cleaning time sequence is field adjustable by turning a potentiometer on the face of the controller. There is one knob for adjusting the cleaning time (0-180 seconds) and a second knob for controlling the purge or “wait time” (the length of time after the end of the cleaning cycle before the door unlocks). The wait time is adjustable from 0 to 15 seconds.

Wall Start Switch

The wall start switch is standard WITHOUT the door interlock magnets option. When someone enters the shower they would have to press the wall start button to activate the cleaning cycle. When the door interlock magnets options is ordered, the unit uses the opening of the door(s) initiate the cleaning cycle.

Lighting

The standard unit includes interior LED lighting with an interior wall light switch

Exit Light Indicator Sequence

The following sequence is part of the standard microprocessor controller program – but it needs to be turned on when you install the air shower. The interior fluorescent light of the air shower is normally off. This conserves power and indicates that it is okay to enter the air shower. When either door opens, the internal fluorescent light turns on. The light will stay on through the cleaning cycle time and the purge/wait time. At the end of the wait time the interior light will flicker off and on to indicate it is okay to exit the shower. The light will remain on while people are in the air shower, but it will turn off when exit door has shut – indicating it is okay to enter the air shower again. In most applications, the people trained to use the air shower are also trained on gowning and cleanroom protocol. With these same people using the air shower every day, the automatic turning on and off of the interior light works extremely well – telling them when to enter and when to exit the air shower.

Blower/Motor

The blower wheel is an energy efficient backward-curved aluminum airfoil. It is direct-drive-mounted to an efficient 5 HP, three-phase motor with sealed ball bearings for low maintenance and long life. The complete assembly is vibration isolated from the rest of the air shower. The blower assembly is mounted on top of the unit with the CAP701KD and is serviced through an access panel on the interior of the air shower.

Filters

The system uses a high-capacity 24 in. x 24 in. x 12 in. deep HEPA wood-framed filter that has a 99.97% efficiency DOP test rating on 0.3 micron particles. The HEPA filter is serviced through an access panel located in the interior ceiling if the air shower. The four 10 in. x 20 in. high efficiency pleated prefilters are located on the lower internal side walls behind a hinged perforated grill to allow easy access. If the raised floor option is ordered, the prefilters are located in the floor grate.

Air Nozzles

There are 32 adjustable air nozzles in each standard air shower section, 16 per side. This provides a uniform concentration of nozzles for fast, effective cleaning. The nozzles are aluminum with a clear anodized finish. They have a 1.2 in. inside diameter, with approximately 7800 LFPM (9000 LFPM peak) nozzle velocity. (Peak velocity is the highest velocity measured at the outlet of the nozzles). This high nozzle velocity provides more cleaning force to effectively dislodge particles and other contaminants.

Air Flow Capacity

The CAP701 provides approximately 1900 CFM total. With this high air flow volume (power), and the high nozzle velocity (force), the people inside the air shower are cleaned faster and more effectively.

Sprinkler Sleeve

The air shower comes with an internal sprinkler sleeve that allows the sprinkler pipe and head to easily be installed (by others). Consult the factory for details.

Flooring Inside the Air Shower

The standard air shower uses the existing building floor.

[ top ]What Optional CAP701 Features are Available?

Option: External and Internal Magnetic Interlocks

With the door interlock magnets, a door start switch is used and the wall start switch is eliminated. A low-voltage magnetic door interlock prevents both doors from being opened at the same time. When one door is opened, the other door’s magnet is energized which prevents the door from opening. During the cleaning cycle, both doors magnets are energized (locked) to prevent anyone from entering or leaving before the cycle is completed. When door interlocks are installed, three “emergency power off” (EPO) panic buttons are provided on the interior and both exterior ends of the shower. When the EPO button is pressed, the interlock magnets deactivate and both doors can be opened. Also, an audible alarm sounds that alerts individuals to the emergency condition. A dry contact option (for a remote sensor or alarm) is available to indicate that the EPO system has been activated. The alarm is turned off by a key switch on the inside wall of the air shower.

Standard Program Sequence with Door Interlock Magnets

Traveling from Gown Room into the Cleanroom:

  • Gown Room Door A opens, cleanroom Door B locks (magnetic interlock).

  • Door A shuts, both Door A & B lock and cleaning cycle starts.
  • At the end of the cleaning cycle both doors remain locked 0 to 15 seconds (adjustable) for the purge/wait time.
  • At the end of wait time, Door B unlocks (people can leave air shower) but Door A stays locked until people have left the air shower and Door B shuts.
  • When Door B shuts, both Door A and B are unlocked and people can enter the air shower from either direction.

Traveling from the Cleanroom to the Gown Room:

  • Door B opens, Door A locks.

  • Door B shuts, Door A unlocks.
  • Door A opens, Door B locks.
  • People exit the shower.
  • Door A shuts, both Door A and B are unlocked.
Note: It is very easy to reverse the door sequence that starts the air showers, so rather than Door A starting, the cleanroom Door B can start the air shower.

Option: Stainless Steel Walls and Cabinet

With the stainless steel shell option, the shell of the exterior and interior air shower is stainless steel. Parts located in the blower compartment behind the interior access panel, i.e., blower, motor, filter support clamps, etc., are standard painted or plated materials and not stainless steel. Consult the factory for further details.

Option: Stainless Steel Control Box

The standard gray painted steel main electrical control box mounted above one door on the exterior of the cabinet is replaced with a stainless steel control box.

Option: Stainless Steel Pharmaceutical Package

The CAP701 has a special set of options specifically designed for pharmaceutical and other applications where microbial contamination is a concern. Please consult the factory for details.

Option: Shipped Fully Assembled on Side

The unit can be shipped fully assembled on its side so it can simply be stood up on site. When shipping on it side, there are typically two eye bolts on the top that can be used to lift the unit. The assembled CAP701-4954 and CAP701-4972 will fit through a 6 ft. x 7 ft. double door. Tunnels can ship in sections.

Option: Assemble from Inside Unit

The unit can be manufactured to allow the installation to be performed from inside the air shower. This is ideal for locations where walls or other obstacles prevent assembly work from the outside of the unit.

Option: Top Mounted Control Box, Remote Mounted Control Box, and Optional Control Box Positions

The control panel can be located in other upper side positions, on a lower exterior side wall, or remote-mounted.

Option: Door Options

  • Steel Construction – Painted. A painted steel door and door frame with a viewing window.
  • Stainless Steel Construction. A stainless steel door and door frame with a viewing window.
  • Acrylic Panel – Full. Clear or tinted acrylic is substituted for clear safety glass on the standard full view door.
  • Split Panel Design – Safety Glass/Stainless Steel. Stainless steel kick plate panels in the lower half of the door and safety glass in the upper half. The stainless steel lower half helps protect the door from potential damage.
  • Split Panel Design – Acrylic/Stainless Steel. Stainless steel kick plate panels in the lower half of the door and clear or tinted acrylic in the upper half. The stainless steel lower half helps protect the door from damage.
  • Door Rub Rails. Anodized aluminum bar rub rails mounted on the lower half of the doors on the interior of the air shower. They are used to protect the air shower doors from potential damage while still allowing a full view window.
  • Power Door Openers. Power door openers are mounted above each door on the outside of the air shower. Push button switches are used to activate opening the doors.
  • Stainless Steel Threshold. Thresholds are used to fill the space between the bottom of the door and the floor – thus keeping dirt and debris from entering the air shower.
  • Door Sweeps – Fixed. Fixed door sweeps are an economical way to fill the space between the bottom of the door and the floor, without adding an obstacle in the doorway. They are mounted to the outside of the door frame and are manually adjustable.
  • Automatic Door Sweeps. Automatic door sweeps provide the best seal between the bottom of the door and the floor, while still allowing the door to open freely and without adding an obstacle in the doorway. The sweep moves upward off the floor when the door is opened and presses down on the floor when the door is closed.
  • Power Sliding Doors. Vertical and horizontal sliding doors are often used when the air shower is used for parts cleaning. Note: When vertical sliding doors are used, the overall height of the doors can exceed the rest of the air shower because of the door lifting mechanism and travel of the door. Also, if a conveyor is being used to transfer parts through the air shower, the shower will typically be taller. Knowing the size of the parts being cleaned and the measurement from the floor to the top of the conveyor will assist us in determining the overall size of the sliding door mechanism. Consult the factory for details on your specific application.
  • No Door(s). Air showers can be furnished without a door(s) on one end so the unit can butt against an existing door. A door interlock magnet can be shipped loose for field mounting. When interfacing with an existing hinged or sliding door, the air shower can be furnished with a dry contact to automatically open the door at the end of the cleaning/wait cycle.

Option: Power Options

  • Units can be ordered for connection to a 480 V 60 Hz, three-phase, four-wire. A 480/120V transformer circuit then provides power for the controls and lights. Typical units are 6.5 FLA per blower section. Each blower section increases the total power required.
  • Units can be ordered for connection to a 575 V 60 Hz, three-phase. Typical units are 5.3 FLA per blower section.
  • Units can be ordered for connection to a 380 V 60 Hz, three-phase, four-wire. Typical units are 8.0 FLA per blower section.

Our website uses cookies. For more information on our cookie use, see our Privacy Policy. By continuing to use this website you agree to our use of these cookies.

Close