United Maintenance, Inc.
Clean Room Reference Page

Types of Cleanrooms:

Cleanrooms may be any controlled environment that regulates particle size and the movement of air in and out of the space.

Softwall Cleanrooms are great for smaller applications, relatively easy to install, maintain and move around within a larger space. Typically constructed with steel or aluminum frames they have clear vinyl curtain strips or panels around the perimeter and are pressurized via fan filter modules. Optics Lab

Modular Cleanrooms are more commonly used for larger cleanrooms inside a manufacturing space. As the name implies, these cleanrooms are flexible to long term expansion and moving large equipment through the removable wall panels. Modular cleanrooms also have the flexibility of utilizing a once thru or recirculating HVAC design. In addition, the variety of wall panel construction and surface material allows these systems to be practical in virtually any environment.

Built-in-Place refers to the larger manufacturing cleanroom environments that are an integral part of the building structure. Most applicable for new construction, these rooms can be built to fit any environment, handle any heat load, classification and incorporate both modular and softwall features within the space. Conversion of smaller office-to-cleanroom renovations incorporate this design as well.

Cleanroom Classifications:

The ISO (International Organization for Standardization) has recently established a guide for controlled environments.

	Class Limits (Particles /m^3)
	0.1 micron	0.2 micron	0.3 micron	0.5 micron	1 micron	5 micron
ISO Classification Number
ISO Class 1	10	2
ISO Class 2	100	24	10	4
ISO Class 3	1,000	237	102	35	8
ISO Class 4	10,000	2,370	1,020	352	83
ISO Class 5	100,000	23,700	10,200	3,520	832	29
ISO Class 6		237,000	102,000	35,200	8,320	293
ISO Class 7				352,000	83,200	2,930
ISO Class 8					832,000	29,300
ISO Class 9						293,000

 

Many people find the older Federal Standard 209 chart easier to understand and apply.

Classes	Particles 0.5 microns or larger / cubic foot
Class 1			1
Class 10			10
Class 100			100
Class 1,000			1,000
Class 10,000			10,000
Class 100,000			100,000

 

There are additional standards applied to the air changes per hour: (filter face velocity = 90 feet per minute)

Class	Air Changes Per Hour m^3 / m^2 x H		Velocity m/s	Type of Airflow
ISO Class 2			0.3 -0.5 m/s	Unidirectional
ISO Class 3			0.3 -0.5 m/s	Unidirectional
ISO Class 4			0.3 -0.5 m/s	Unidirectional
ISO Class 5			0.2 -0.5 m/s	Unidirectional
ISO Class 6		70-160		Non-Unidirectional or Mixed
ISO Class 7		30-70		Non-Unidirectional or Mixed
ISO Class 8		10-20		Non-Unidirectional or Mixed
ISO Class 9		0-10		Non-Unidirectional or Mixed

 

Architectual Finish:

Cleanrooms come in all shapes and sizes and as such a variety of materials is often necessary. Most of the time the wall, ceiling, and floor materials are determined by economics, however, keep in mind that certain process chemicals and gases, cleaning agents and acids react differently to certain substrates. Consult your MSDS for more specific information.

Flooring options include: solid heat seam-welded vinyl, self-leveling epoxy, tile floors and conductive raised access flooring.

Wall Materials can be aluminum, vinyl hardboard, painted steel, stainless steel, PVC, and epoxy painted sheetrock.

Grid Systems may be PVC or anodized aluminum, range from 1", 1.5" or 2" wide. The seal may be a gasket of low-off gassing cellular urethane, low VOC material, neoprene, polyethylene, antibacterial, or fire retardant. 2" wet-seal grid systems are also available used knife edge ceiling tiles and filters.

Ceiling Tiles may be vinyl hardboard with sealed edges, aluminum, steel or PVC.

Lighting may be provided using 2' x 4' troffers, tear drop light fixtures, integrated flow thru light troffers, yellow lenses and a variety of bulbs.

Filters are either HEPA or ULPA, efficiencies ranging from 99.97% efficient at 0.5 microns to 99.99995% at 0.12 microns. Depending on the mechanical design, Terminal diffusers or Fan Filter Modules may be used. Other options include gaskets downstream, room-side replaceable filter housing, and size.

Ionization is used for critical environments where static charge is a concern, emitting positive and negative ions into the space neutralizing the surface area. Systems range from complete room ionization using ceiling emitters to more localized blowers and fans. Installation and certification are included on all room ionization packages.

Particle Counting Systems may be as simple as a portable particle counter to larger machines with remote sensors monitoring particle size, matter, and frequency. Most sytems are programmable or come with computer software that can create graphes and charts for display.

Cleanroom Certification is assurance that your cleanroom meets spec and provides your customers with confidence of the manufacturing environment.

Air Showers are used to gain entry into cleanrooms blowing filtered air on and around the person to remove any surface contaminants before entering the clean space.

Pass Thrus are small airtight enclosures in the wall used to pass sensitive material from one room to another without being contaminated.

More questions? Call: 770-455-1656