Clean Room Design Principles

When your goal and project or product or even research or construction in a space that is as much as possible controlled by environmental parameters, it is important to consider the principles of clean room design and construction of the site you want . This means that careful planning must be done for airflow, clean room pressure, clean room airborne particles, clean room temperature, relative humidity, and other factors that may affect the required clean room classification.

Clean rooms for clean processes that can range from pharmaceutical production and packaging, medical laboratory and academic research, aerospace industrial applications, computer components, semiconductors, injection molding, liquid vapors, medical cannabis and many more Used and a vital requirement.

There are many important factors to consider when planning to build a clean room. In this post, we want to start with the basics of "cleaning" a clean room


Is everything dependent on airflow?

This is not entirely true. There are other factors that can negatively affect your work, but how you control air quality is the key to achieving success in achieving your clean space standard. The main concern is the concentration of particles and microbial contamination in the air or space of the clean room. Here are four factors that will help you define the cleanliness of your clean room.

Is everything dependent on airflow?

Filtration systems - At the heart of most clean rooms is a highly efficient particulate air purification system called a HEPA filter. Areas that need even cleaner air may use more complete filters called ULPAs.

ISO Classification - In clean room spaces, air cleanliness is classified according to ISO 14644-1 Cleanroom Standard. ISO 1-9 classifies air quality based on the number of particles in the environment with different microscopic sizes. The lower the ISO number, the higher the sensitivity of the output and the "cleaning" of the room. Conventional production operations are performed in clean rooms with ISO 7 or 8 classification.

Air changes per hour - Air changes per hour measure the number of times air passes through room filters. The higher the passage, the fewer particles there are in the air. Ach is calculated by dividing the volume of air passing through HEPA filters by the volume of the room.
An ISO 5 space will circulate around 240 to 360 ach, while an ISO 8 function will only include 10 to 25 ach. For comparison, a typical room or office area takes about two to four ach.

Air Circulation Strategy - Clean room air circulates in one of two ways.

  1. Air flow recirculation - supply of clean and air conditioned air to clean room space through HEPA terminal filter and return to AHU via return channel
  2.  Single Pass air flow - Provide clean and air conditioned air to the clean room space through the HEPA terminal and enter it outside.
    There are advantages to both methods.
    If your performance is also sensitive to temperature and humidity, rotating airflow may be a preferred strategy.
    Air expelled from the air stream with a passage due to the evacuation of air from the environment helps to reduce small loads as well as hazardous concentrations.


Clean room application?

The environmental sensitivity of the work to be done in a clean room determines the needs of ISO-based clean air classification.

For example, medical equipment, cell therapy and gene therapy research laboratories, and sterile injectable vaccines are produced in clean rooms with ISO 5 class-sensitive ratings. Solid medicine, touch screen membrane assembly is performed in ISO 7 environment, while general production processes, non-sterile compounds require only an ISO 8 workspace.

Clean room application?


Think thoroughly about the design

In addition to the clean room, the surrounding space should also be considered. No matter how well the airflow is controlled, there may be cases of intrusion and explosion. Also, regardless of how the clean room is designed, air pollution is possible through the doors. In fact, an important design point is a door that reduces air loss through this architectural feature.

The surrounding space is very important. Clean rooms should be designed so that there is no difference of more than two degrees between adjacent clean rooms. For example, an ISO 5 space can be next to an ISO 7 room, but should not be attached directly to a clean ISO 8 room.

See how air penetrates and leaks from your space
Air, sometimes in unplanned and unpredictable ways, enters (enters) a clean room and leaves. The goal is to control the incidence of both. Air leakage should be controlled at a speed of 1 to 2%.

By adjusting the air pressure inside, the amount of air filtration can be controlled from the outside. Positive air pressure controls "dirty" air from adjacent spaces and prevents it from entering a clean room. Having a pressure differential of 0.02 to 0.05 hydrometer (w.g.) between the space and the dirtier environment greatly reduces the risk of contaminants penetrating.

It is important to minimize architectural air outlets. Penetration occurs through room lighting fixtures and electrical outlets, door and window frames, and where walls meet floors and ceilings. These are important when designing a clean room space.
Building materials

When creating a clean room space, it is important to use materials that cause shedding, particulate matter, space for microorganisms, or static electricity. The surface should also be suitable for easy cleaning. The best smooth and easy to clean materials include HPL, powder coated GI, glass, stainless steel and other materials. The best clean room.

Material quality, strength, modularity and durability are other factors that should be considered when reducing leakage and maintenance.

Walls, ceilings, doors, modular windows can be built with the concept of GMP principles (good construction method).


Employees are also polluting

Consider the workflow as well as the airflow. It is estimated that up to 80% of clean room pollution is due to workers in the clean room space.

Reduce pollution by having access corridors and entrance doors. It is also important to create a controlled space environment that is large enough to meet your needs. Consider the number of workers, the work they do, how it works, and even the entry and exit points of materials. To maintain a clean room, it is important to design an optimal personal and material flow that can reduce cross-contamination. Many companies design facilities that have a one-way flow pattern, separate entry and exit points, and appropriate evening dress methods.

Depending on your application and workflow, there may be many factors to consider.


  • What comes out of a clean room - do they interfere with a particular level? Remove as much as you can during design and construction. Common offenders include:
  • Lights
  • Smoke detectors
  • Strengths
  • Sprinklers
  • Fire doors

Power supply and lighting

Know where this equipment is located and how it is located, then coordinate the location of the power points / MCC.

  • Power outlets should be embedded in the wall (slim design), without sharp edges. Make sure no service / cabling is exposed to a clean room.
  •  How is it serviced? Can this be done from outside
  • the room or do you need to close the room to replace the lamp connections? Use sealed IP65 lighting types with high maintenance access. LED lighting types are preferred.
  • Make sure there is enough light level for the required work, ie 400 lux recommended in AS / NZS 1680. Also make sure the light is uniform.
    Do you do certain tasks that require a higher level of brightness? For example, in instrumentation, inspection and so on
  • Lighting control modules should be located outside a clean room.
  • Provide emergency lighting and output to the current needs of the building code.
    View Window - Corridors
  •  Have you seen enough windows in the clean room for the supervisor / visitor to pass through without entering the clean room?


If you have a window between two sterile areas, consider double-glazed windows - this will allow the glass panes to align with the wall (without thresholds), making it easier to clean.

  • Air lock

Having personal and material air locks should be considered. It depends on the program, it can be separate or combined.

  • Personal air lock is used to cover and separate to enter a clean room from non-GMP areas.


Frequently Asked Questions

Q: - What are the suggested instructions for designing and building a clean room?

ISO 14644-4: 2001 - Cleanroom design, construction and commissioning

Q: What is the ISO classification for clean rooms and how are they defined?

Clean rooms are classified based on how clean the air is. Creating a clean ISO room is an advanced process that measures air quality. In designing and cleaning a clean room, it is important to determine the quality of cleaning in an ISO Clean room and the various clean room designs produced by Andishgaran Company.
Air change every hour is also an important criterion that must be approved in order to be certified as a clean ISO room. The following is the FS209E classification for air change rates:

Q: What is the ISO classification for clean rooms and how are they defined

Q: - Clean room certification reference

The Cleanroom Certification Test is recommended to be performed in accordance with FS 209E and ISO 14644 classification guidelines and IEST-RP-CC006.3.

Q: - What are the different ways to build a clean room?

A. Ordinary construction - gypsum wall with epoxy paint
B. Modular construction - prefabricated panels insulated with aluminum, HPL, GI.
C. Coating on existing structure - FRP, PVC, aluminum sheet
Q: - What are the permissible particles in each ISO classification?
The following is a table of ISO 14664-1 clean room system standards

What are the permissible particles in each ISO classification

We hope that at the end of this article, the mentioned contents have been useful for you, and whenever you need advice, design and construction of a clean room, the experts of Andishgaran Company are ready to cooperate with you.