Selecting materials and components for cleanrooms
Choosing which materials to use for a cleanroom construction is increasingly complex due to the wide variety of options now available. Jorge Nuero, Telstar, looks at key considerations for optimising cost and ensuring safety and quality
When deciding on the materials and elements to be used in the construction of a cleanroom, it is necessary to keep in mind the specific requirements and working conditions of each area. Only through appropriate design will the cost of installation be optimised and the resulting facility offer long-term safety and quality standards that meet user requirements.
The traditional building methods – where the walls and ceilings are constructed on site from raw materials, followed by the application of a PVC or epoxy finish coating – are rapidly being replaced by the use of modular elements built using self-supporting, factory-made sandwich panels.
This transition has occurred due to the many advantages offered by the use of modular elements, including:
rapid and clean installation
improved tracking of materials
reduction in waste and construction residue
reduction in variability introduced by those performing the installation
increase in quality (due to the fact that the materials are factory manufactured and finished to precise, pre-determined specifications)
better defined values of mechanical and chemical resistance and lower permeability to air and water
The main disadvantage of the modular method is that it is less flexible when the time comes to make changes in design, since it needs to be fully specified and designed in advance, which also requires that joints be added between existing elements to provide transitions between exiting and new construction.
There are a wide number of options when considering the use of sandwich panels, which in turn enable an optimal solution to each specific set of requirements to be attained.
The need for more modular designs has led to increased use of layered panels
The fundamental parameters applicable to defining a panel are as follows: thickness; core material; material and thickness of the skins (exterior surfaces); external finish; type of jointing or fastening system; whether or not a perimeter frame is required, and behaviour and resistance to flames. It is important to distinguish between ‘behaviour’ and ‘resistance’, as failure to do so can result in specification errors.
The behaviour of a material in the presence of fire or in reaction to fire is classified in European Standards according to Norm UNE-EN 13501-1:2007 and is based on three fundamental parameters:
Fire certification, from Class A (inert materials) to Class F (highly combustible materials)
Level of smoke production, from S1 (low smoke production) to S3 (high smoke production)
Level of production of liquid droplets, from d0 (does not produce droplets) to d2 (high number of droplets)
The fire resistances (previously RF) of elements that comprise an enclosure are regulated by Norm UNE-EN-11501-2:2009, which defines that fire resistance is primarily based on three parameters: bearing capacity (R), integrity (E) and insulation (I). For example, a material with a resistance of REI-60 will maintain each of these three characteristics for at least 60 minutes.
This norm also states the types of tests to be performed for partitions that separate two independent fire sectors, which is not common in cleanrooms, except in certain instances (ATEX rooms, partitions for separation from other areas, such as storage areas, offices, technical zones, etc.).
The norm that should be followed when working with insulating sandwich-type portable, double-faced metallic panels is Norm EN 14509:2005.
From a process perspective, the most critical element to consider is the material used for the surface or skin that will be in direct contact with the room’s inner environment. In this respect, it is important to know the cleaning and sanitation methods that will be employed and to select the finishes accordingly.
For example, for a washing area where pressurised water is used daily, partition surfaces in stainless steel can be justified. In addition, use of slip-resistant flooring with appropriate slope towards the drain is required. Such considerations would not apply to a packaging area, where an impact-resistant panel is more appropriate.
Stainless steel is ideal for areas where harsh cleaning chemicals will be used
For areas where hydrogen peroxide is used as a disinfectant or bio-decontamination agent, the use of special insulation (type PET, PVDF) and surfaces of epoxy laminated resins intertwined at high pressure (HPL) or the use of stainless steel needs to be considered. In this case, decisions would be influenced not only by cost but also by the sanitising method employed, the frequency of application and the concentration of the particular chemical agent.
The purpose of the room also needs careful consideration. For example, it is not necessary to achieve the same level of air tightness in a laboratory for quality control, working under positive pressure as that in a zone where vaccines or cultures with biological hazards are present. In this latter case, it is necessary to perform tests that demonstrate the absence of leaks in ceilings and walls, secondary barriers of the containment area, and to design with double sealing of all panels, utility, electrical and mechanical penetrations, light fixtures and filter assemblies. In addition, doors may require inflatable joints and drains may require hydraulic seals.
Flooring options
Floors that are typically installed in cleanrooms are of two basic types: epoxy resin or PVC. The selection of which floor material to employ depends on several factors. Resin floors are recommended for rooms where water is present or high humidity is expected, i.e. washing areas, steam outlets, etc. Another factor to consider is the mechanical load that will be presented when objects are moved. In this respect resin floors provide a higher resistance and strength.
PVC floors in a tile format or laid from a roll (welded joints in both cases) are considerably more economic and easy to install and replace. They are recommended for labs, hallways, or rooms that do not handle a high volume of traffic or movement of heavy objects.
Epoxy resin flooring used in a packing area
In certain areas where humidity is low or where there is an ATEX classification, conductive floors (made of resin or PVC) are used to prevent static electricity. Following installation, it is necessary for a certified contractor to perform some conductivity measurements to confirm the correct installation and grounding connection.
Critical points that need to be taken into consideration during the design and installation phases include:
Use of a vapour barrier that prevents any humidity infiltration that could produce bubbles of gas or water (in the case of PVC) or cracks (in the case of resins). The relative humidity in the existing slab should be measured before installation and an interior humidity of less than 3% is recommended.
The surface should be smooth, clean and level, due to the fact that the finished surface will replicate the defects found in the base, including any slope, cracks or irregularities in the surface. The use of a self-levelling substrate or surface levelling compound can correct these defects to a degree, but can use large amounts of material.
Particular attention should be paid to the proper treatment and sealing of the expansion joints and the connection with other critical elements such as panels, drainage, etc., which tend to be weak points.
The European norm for PVC floors is EN 14041 and EN 13813:2002, for industrial multi-layer pavements (epoxy resin). Floors should also comply with the requirements established by 2033/94/ECC relating to GMP recommendations.
Locating viewing panels
The design and location of the viewing panels within the cleanroom is important, not solely from an aesthetic perspective but also for providing user comfort and operational efficiency. For example, the use of view panels in a partition separating a filling line from its respective packing line enables operators in both rooms to have visual contact and provide simple instructions without having to leave their post. For this reason, considered location during the design phase is critical.
From the aesthetic point of view, frequently the viewing panels are located in wall panels of visiting and inspection halls, which permit the facility to be visited or supervision tasks of the operators and equipment to be carried out without the need to disrupt the operation and without needing to follow the strict protocols for admittance into controlled areas. The use of view panels to the exterior is also very helpful to the operators when working on repetitive tasks because it enables them to better take brief periods of relaxation while working without having to leave their area.
Strategic design for siting windows
Usually, the requirements are for viewing panels to be flush on both sides of the wall and the void between each pane should contain drying agents to prevent humidity condensing. In addition, the glass used should be tempered, so that in the case of breakage, it shatters into small pieces, not shards or sharp fragments. In special cases, such as evacuation routes, laminated glass should be utilised. In ATEX zones or walls dividing different sectors, windows must be reinforced and fire resistant. In the case of photosensitive products, where decontamination is performed through ultraviolet methods, the windows are usually protected with coatings or films that filter the respective wavelength.
Choose easy-to-clean doors
Design of a clean and flushed door
The design of cleanroom doors should be kept as simple as possible, avoiding the use of elements that are difficult to clean, that have areas difficult to access or utilise rails or complex mechanisms. Swing doors are recommended for most applications; they are simple and more easily cleaned than roll-up or sliding doors. However, with swing doors, it is not recommended to use perimeter joints due to the fact that they deteriorate with time and are often placed on rails that are very difficult to keep clean.
For the same reason, the use of electrical, mechanical or hidden hinge devices to close the doors is not recommended. Both sides of the door should be flush with the wall, to avoid uneven surfaces when it comes time to clean.
In conclusion, selecting materials of construction for cleanrooms is becoming increasingly complex due to the wide variety of options that are now available. Understanding the requirements of the end-user and the specific processes that will be carried out in the cleanroom environment are crucial to a successful installation. Key factors to be considered are cost, layout and ergonomics, safety and fire regulations, energy consumption and standards and norms. For these reasons it is important to involve an experienced supplier at the very onset of the project, to be a partner from concept design to handover.
Companies
A Basic Introduction to Clean Rooms — CLEANROOM SOLES
A Basic Introduction to Clean Rooms
By Roger McFadden
Senior Scientist, Staples Inc.
A cleanroom is a controlled environment where products are manufactured. It is a room in which the concentration of airborne particles is controlled to specified limits. Eliminating sub-micron airborne contamination is really a process of control. These contaminants are generated by people, process, facilities and equipment. They must be continually removed from the air. The level to which these particles need to be removed depends upon the standards required. The most frequently used standard is the Federal Standard 209E. The 209E is a document that establishes standard classes of air cleanliness for airborne particulate levels in cleanrooms and clean zones. Strict rules and procedures are followed to prevent contamination of the product.
The only way to control contamination is to control the total environment. Air flow rates and direction, pressurization, temperature, humidity and specialized filtration all need to be tightly controlled. And the sources of these particles need to controlled or eliminated whenever possible. There is more to a clean room than air filters. Cleanrooms are planned and manufactured using strict protocol and methods. They are frequently found in electronics, pharmaceutical, biopharmaceutical, medical device industries and other critical manufacturing environments.
It only takes a quick monitor of the air in a cleanroom compared to a typical office building to see the difference. Typical office building air contains from 500,000 to 1,000,000 particles (0.5 microns or larger) per cubic foot of air. A Class 100 cleanroom is designed to never allow more than 100 particles (0.5 microns or larger) per cubic foot of air. Class 1000 and Class 10,000 cleanrooms are designed to limit particles to 1000 and 10,000 respectively.
A human hair is about 75-100 microns in diameter. A particle 200 times smaller (0.5 micron) than the human hair can cause major disaster in a cleanroom. Contamination can lead to expensive downtime and increased production costs. In fact, the billion dollar NASA Hubble Space Telescope was damaged and did not perform as designed because of a particle smaller than 0.5 microns.
Once a cleanroom is built it must be maintained and cleaned to the same high standards. This handbook has been prepared to give professional cleaning staff information about how to clean the cleanroom.
What is Contamination?
Contamination is a process or act that causes materials or surfaces to be soiled with contaminating substances. There are two broad categories of surface contaminants: film type and particulates. These contaminants can produce a “killer defect” in a miniature circuit. Film contaminants of only 10 nm (nanometers) can drastically reduce coating adhesion on a wafer or chip. It is widely accepted that particles of 0.5 microns or larger are the target. However, some industries are now targeting smaller particles.
A partial list of contaminants is found below. Any of these can be the source for killing a circuit. Preventing these contaminants from entering the cleanroom environment is the objective. It requires a commitment by everyone entering the cleanroom to make it happen. Professional cleaning personnel need to be aware of the importance of controlling contaminants. Strict procedures should be followed whenever entering or cleaning a cleanroom. Compromise is not acceptable when cleaning in a cleanroom.
Sources of Contamination
This is a partial list of some of the commonly known contaminants that can cause problems in some cleanroom environments. It has been found that many of these contaminants are generated from five basic sources. The facilities, people, tools, fluids and the product being manufactured can all contribute to contamination. Review this list to gain a better understanding of where contamination originates.
1. Facilities
Walls, floors and ceilings
Paint and coatings
Construction material (sheet rock, saw dust etc.)
Air conditioning debris
Room air and vapors
Spills and leaks
2. People
Skin flakes and oil
Cosmetics and perfume
Spittle
Clothing debris (lint, fibers etc.)
Hair
3. Tool Generated
Friction and wear particles
Lubricants and emissions
Vibrations
Brooms, mops and dusters
4. Fluids
Particulates floating in air
Bacteria, organics and moisture
Floor finishes or coatings
Cleaning chemicals
Plasticizers (outgasses)
Deionized water
5. Product generated
Silicon chips
Quartz flakes
Cleanroom debris
Aluminum particles
Key Elements of Contamination Control
We will look at several areas of concern to get a better idea of the overall picture of contamination control. These are the things that need to be considered when providing an effective contamination control program.
HEPA (High Efficiency Particulate Air Filter) - These filters are extremely important for maintaining contamination control. They filter particles as small as 0.3 microns with a 99.97% minimum particle-collective efficiency.
CLEANROOM ARCHITECTURE - Cleanrooms are designed to achieve and maintain a airflow in which essentially the entire body of air within a confined area moves with uniform velocity along parellel flow lines. This air flow is called laminar flow. The more restriction of air flow the more turbulence. Turbulence can cause particle movement.
FILTRATION - In addition to the HEPA filters commonly used in cleanrooms, there are a number of other filtration mechanisms used to remove particles from gases and liquids. These filters are essential for providing effective contamination control.
CLEANING - Cleaning is an essential element of contamination control. Decisions need to made about the details of cleanroom maintenance and cleaning. Applications and procedures need to be written and agreed upon by cleanroom management and contractors (if used). There are many problems associated with cleaning. Managers need to answer the following questions before proceeding with any cleanroom cleaning program:
1. What is clean?
2. How is clean measured?
3. What cleaning materials can be used in the cleanroom?
4. When can the cleanroom be cleaned?
5. How frequent does it need to be cleaned?
CLEANROOM GARMENTS - The requirements for cleanroom garments will vary from location to location. It is important to know the local garment requirements of the cleanroom management. Gloves, face masks and head covers are standard in nearly every cleanroom environment. Smocks are being used more and more. Jump suits are required in very clean environments.
HUMANS IN CLEANROOMS - There are both physical and psychological concerns when humans are present in cleanrooms. Physical behavior like fast motion and horseplay can increase contamination. Psychological concerns like room temperature, humidity, claustrophobia, odors and workplace attitude are important. Below are several ways people produce contamination:
1. Body Regenerative Processes-- Skin flakes, oils, perspiration and hair.
2. Behavior-- Rate of movement, sneezing and coughing.
3. Attitude-- Work habits and communciation between workers.
People are a major source of contamination in the cleanroom. Look at the people activies listed below. Notice the number of particles produced per minute during these activities.
PEOPLE ACTIVITYPARTICLES/MINUTE (0.3 microns and larger)
Motionless (Standing or Seated)100,000
Walking about 2 mph5,000,000
Walking about 3.5 mph7,000,000
Walking about 5 mph10,000,000
Horseplay100,000,000
COMMODITIES - Care is taken when selecting and using commodity items in cleanrooms. Wipers, cleanroom paper and pencils and other supplies that service the cleanroom should be carefully screened and selected. Review of the local cleanroom requirements for approving and taking these items into the cleanroom are essential. In fact, many cleanroom managers will have approval lists of these types of items.
COSMETICS - Many cosmetics contain sodium, magnesium, silicon, calcium, potassium or iron. These chemicals can create damaging particles. Cleanroom managers may ban or restrict cosmetics in the cleanroom. This is usually dependent upon the threat to the product being made in the cleanroom. A recent mirror on a space telescope was fogged up from the cologne that was present in the cleanroom.
MEASUREMENT AND INSTRUMENTATION - Some important measurements related to contamination control are particle count, air flow & velocity, humidity, temperature and surface cleanliness. Cleanroom managers usually have specific standards and/or instruments to measure these factors.
ELECTROSTATIC DISCHARGE (ESD) - When two surfaces rub together an electrical charge can be created. Moving air creates a charge. People touching surfaces or walking across the floor can create a triboelectric charge. Special care is taken to use ESD protective materials to prevent damage from ESD. Cleaning managers should work with their personnel to understand where these conditions may be present and how to prevent them.
Cleaning Procedures for Clean Rooms
What follows are some recommended procedures for cleaning cleanrooms. It is important to emphasize that these procedures are guidelines and not standards or rules. The procedures listed here are routine cleaning tasks. Local cleanroom cleaning procedures may supercede the ones listed here. It is important for cleaning managers to review all cleaning procedures to be used in a cleanroom with the cleanroom management. A detailed cleaning schedule should be prepared for every cleanroom. Here are some procedures to be completed when cleaning a Class 10,000 cleanroom:
Cleaning Procedures for a Class 10,000 Cleanroom
Housekeeping maintenance of the cleanroom and restricted areas is essential to assure quality. Cleaning of a cleanroom should be performed on a daily basis. Improper cleaning of the cleanroom can lead to contamination and a loss in end user product quality. Proper selection of equipment and materials is important for proper cleaning. Only products that have proven cleanroom performance records should be considered for use in cleanrooms. These products should be listed and all vendors should be informed about the strict policies of how products are qualified. All procedures should be strictly enforced. Below are some examples of how to organize the cleaning to be done in a cleanroom. These are NOT schedules or exact procedures. They are guidelines for preparing work procedures and schedules. Local requirements must be included in any cleaning program.
List of Some of Equipment and Supplies Needed to Clean the Cleanroom
(All supplies must meet the Class 10,000 minimum requirements)
1. Cleaning and disinfecting solutions
2. Cleanroom mops
3. Cleanroom vacuum cleaner (if allowed)
4. Cleanroom wipers
5. Cleanroom mop bucket and wringer
List of Cleaning Tasks to be Completed in the Cleanroom
(Frequency may vary depending upon local requirements)
1. Cleaning of all work surfaces in the controlled environment.
2. Vacuuming (if allowed) of the floors and work surfaces.
3. Emptying of appropriate trash and waste.
4. Cleaning of the doors, door frames and lockers in the pre-staging area and gowning areas using the approved cleaning solution.
5. Mop gowning and cleanroom floors.
Cleaning Procedures for a Class 1000 Cleanroom
Below is a sample of a cleaning program in a Class 1000 Cleanroom. This is only a sample of a program. Local standards and requirements must be followed.
AreaDescription of WorkFrequency
101Change tacky matsEvery 2 hours
102Wet mop with approved mop, cleaner & DI water2 times per shift
103Dust mop (if allowed)2 times per shift
104Remove trash, sweep, mop with appropriate cleaner wipe down tables and coffee area, clean walls and recycle cans1 time per shift
105Vacuum entry mats, sweep and mop floors1 time per shift
106Mop floor with pre-burnish cleaner and tap water1 time per shift
107
Remove trash. Always wear gloves. Never take waste containers inside cleanrooms.
1 time per shift
108Wet mop floors1 time per shift
109Remove acid and solvent trash1 time per shift
110Clean and replenish dispenser in all restrooms3 times per week
111Vacuum floor (if allowed)2 times per week
112
Clean stainless steel pass throughs with s/s cleaner and appropriate wipes
1 time per week
The list above is a sample of some of the common tasks that need to be performed in a Class 1000 cleanroom. The list is not exhaustive. But gives some ideas of how to prepare work schedules and procedures. An assessment of the cleanroom in conjunction with cleanroom management will help define these tasks and frequencies.
Cleaning Procedures for a Class 100 Cleanroom
ZoneProcedureFrequency
Zone 1aTrash removalOnce daily
Mop walkwaysOnce a week
Wipe down horizontal surfacesOnce monthly
Zone 1bPull tacky matsEvery 2 hours
Zone 1cMop and trash removalOnce daily
Wipe down walls and trimOnce a week
Zone 1dMop and trash removalOnce daily
Wipe walls and trimOnce a week
Zone 2aMop Twice a shift
Wipe walls and trimOnce a week
VacuumOnce monthly
Zone 2bMop and trash removalOnce per shift
Zone 2cWipe down walls, windows, doors, trim, showers, passthroughs and fire extinguishers.Once a week
The list above is a sample of some of the common tasks that need to be performed in a Class 100 cleanroom. The list is not exhaustive. But gives some ideas of how to prepare work schedules and procedures. An assessment of the cleanroom in conjunction with cleanroom management will help define these tasks and frequencies.
General Cleanroom Regulations
Below is a list of general regulations recommended as a minimum for the successful operation of a cleanroom. All professional cleaning personnel should be aware and follow these regulations at all times.
1. All personal items such as keys, watches, rings, matches, lighters and cigarettes should be stored in the personal locker outside the gowning room.
2. Valuable personal Items such as wallets may be permitted in the cleanroom provided they are NEVER removed from beneath the cleanroom garments.
3. NO eating, smoking or gum chewing allowed inside the cleanroom.
4. Only garments approved for the cleanroom should be worn when entering.
5. NO cosmetics shall be worn in the cleanrooms. This includes: rouge, lipstick, eye shadow, eyebrow pencil, mascara, eye liner, false eye lashes, fingernail polish, hair spray, mousse, or the heavy use of aerosols, after shaves and perfumes.
6. Only approved cleanroom paper shall be allowed in the cleanroom.
7. Approved ball point pens shall be the only writing tool used.
8. Use of paper or fabric towels are prohibited. Use of hand dryers equipped with HEPA filters are suggested.
9. Gloves or finger cots should not be allowed to touch any item or surface that has not been thoroughly cleaned.
10. Only approved gloves, finger cots (powder-free), pliers, tweezers should be used to
handle product. Finger prints can be a major source of contamination on some products.
11. Solvent contact with the bare skin should be avoided. They can remove skin oils and increase skin flaking.
12. Approved skin lotions or lanolin based soaps are sometimes allowed. These can reduce skin flaking.
13. All tools, containers and fixtures used in the cleaning process should be cleaned to the same degree as the cleanroom surfaces. All of these items are a source of contamination.
14. NO tool should be allowed to rest on the surface of a bench or table. It should be place on a cleanroom wiper.
15. Only cleanroom approved wipers are allowed to be used. The wipers must be approved for the Class of cleanroom being cleaned.
16. ALL equipment, materials and containers introduced into a sterile facility must be subjected to stringent sterilization prior to entrance.
17. NO ONE who is physically ill, especially with respiratory or stomach disorders, may enter a sterile room. This is a good practice in any cleanroom environment.
Personal Actions Typically Prohibited in Cleanrooms
1. Fast motions such as running, walking fast or horseplay.
2. Sitting or leaning on equipment or work surfaces.
3. Writing on equipment or garments.
4. Removal of items from beneath the cleanroom garments.
5. Wearing the cleanroom garment outside the cleanroom.
6. Wearing torn or soiled garments.
Lighthouse Worldwide Solutions
If you’re working for a company already using a cleanroom, you’re well aware of the benefits of a cleanroom and how important they are. But if you’re wondering how you can improve your production, then a cleanroom might be the answer.
Either way, a cleanroom is not a simple beast. It is a multi-layered room that needs to be constantly monitored and maintained. Having a basic understanding of the fundamentals of what a cleanroom is will change the way you interact with your cleanroom.
What Does A Cleanroom Do?
A cleanroom does just that: it keeps things clean. They are used in several industries where particles in the air can impact the outcome of a physical product.
Essentially, a cleanroom is a highly sterilized environment where air must pass through a filter to enter the area. The main contaminant is the humans who enter and exit the room. But, other than that, the filter keeps small particles out of the room, which is constructed out of smooth, antistatic materials.
Who Uses A Cleanroom?
Cleanrooms are used by technicians and manufacturers in production in numerous industries. Some of the most common industries include:
Electronics
Pharmaceuticals
Biotechnology
Life sciences
Food manufacturing
Automotive
All these industries require strict monitoring of environmental factors during production. These environmental factors include pressure, temperature, and particle saturation of the air in the room – all of which can be monitored and controlled in a cleanroom.
How Are Cleanrooms Classified?
A cleanroom is classified depending on how clean the air is (or needs to be). To classify a cleanroom, you would use a particle counter to take a sampling of the air and examine how many particles are found. This is considered the known sample of the room. The cleaner the air (i.e. the lower the particle concentration), the higher the classification of the cleanroom.
There are two main ways to classify cleanrooms.
In the USA, cleanrooms can be classified using the Federal Standard 209 (FS 209). There are several classifications labeled FS 209A through FS 209E. This standard was established in 1963 by the Institute of Environmental Sciences and Technology (IEST). Most recently, FS 209E established the maximum number of particles to be counted as a cleanroom.
As for international standards, another way to classify cleanrooms is through ISO 14644-1. This standard was established in 1999. ISO is an independent organization dedicated to establishing international standards of best practice.
Ultimately, FS 209 E (the US standard) and ISO 14644-1 (the international standard) reflect the same measurements to classify a cleanroom at certain levels.
Classifications Of Cleanrooms
There are 9 ISO classifications of cleanrooms:
ISO 1
ISO 2
ISO 3 (FS 209 E class 1 equivalent)
ISO 4 (FS 209 E class 10 equivalent)
ISO 5 (FS 209 E class 100 equivalent)
ISO 6 (FS 209 E class 1,000 equivalent)
ISO 7 (FS 209 E class 10,000 equivalent)
ISO 8 (FS 209 E class 100,000 equivalent)
ISO 9 (room air)
ISO 1 is considered the cleanest possible room, with a known sample having 10 or fewer particles measuring .01 microns and 2 or fewer particles measuring 0.2 microns.
ISO 9 is normal room air, with a known sample having 35,200,000 or fewer particles measuring 0.5 microns, 8,320,000 or fewer particles measuring 1 micron, and 293,000 or fewer particles measuring 5 microns.
See Figure 1 for a full graph depicting the micron necessities for each classification.
What Are The Components Of A Cleanroom?
There are four zones in a cleanroom: the outdoor environment, ancillary areas, surrounding cleanrooms, and interior clean zones.
Humans and products to be worked on come from the outdoor environment. The work is done in the interior clean zones. But each zone (aside from the outdoor environment) should be monitored for its level of particulates.
Interior Components Of A Cleanroom
The heart of the cleanroom is the Air Handling Unit (AHU). AHUs contains a centrifugal fan – which is a fan designed to pull in air and change its direction. Cleanrooms use a lot of air and it is continually being circulated and filtered to maintain peak cleanliness, so these fans are critical to the success of the room. The size of the fan depends on the size and air needs of each specific room.
The AHUs also contain the filters used to clean the air. The air goes through several filtration stages. Typically, AHUs use High Efficiency Particulate Air (HEPA) filters, which has a 99.97% efficiency rate at the most penetrable particle size, 0.3 microns. They are made of glass fiber, which is interlaced for maximum efficiency. In some instances, an Ultra-Low Particulate (ULPA) filter may also be used. These filters catch particles that are 0.12 microns. These are most often found in cleanrooms where semiconductors are produced.
Air also passes through a cooling coil in the AHU to dehumidify it. A cooling coil could be either direct expansion (DX) or chilled water (CW) depending on the design of the AHU. Direct expansion coils use refrigerant to dehumidify and cool the treated air, whereas chilled water coils use water and fins to dehumidify and cool the air.
Does Your Business Need A Cleanroom?
If you’re reading this, your business may already use a cleanroom and you’re trying to understand them better or you might suspect that your business could benefit from a cleanroom.
So ask yourself these following questions to decide if a cleanroom is right for your business:
Does your business produce micro-level goods?
Does your business produce food?
Does your business partake in scientific research?
Do your products continually malfunction due to hardware issues from particles interacting with the product?
If you answered yes to any of the above questions, then your business could benefit from a cleanroom. While they are an investment and take careful monitoring, they can ultimately benefit your production immensely.
And you want to make sure you are caring for your investment and making the most of it. As one of the leaders in cleanroom monitoring solutions, we want to make sure your cleanroom is working harder for you than you are for it.
Want to make sure your cleanroom is at its peak performance? Contact us today.
