Understanding the Design & Construction of Cleanrooms
Cleanrooms are specialized workspaces for critical processes and operations. They are designed to maintain strict standards of cleanliness for certain types of manufacturing and product preparation. Cleanrooms are commonly used for some applications in the manufacture of electronics, semiconductors, pharmaceuticals, medical devices, and aerospace equipment, as well as in labs and research settings.
Here, we’ll look at the major goals of cleanroom design, how they are constructed to meet those goals, and some of the standards cleanrooms must meet.
Understanding the Design & Construction of Cleanrooms
Cleanroom design is focused on controlling the environmental conditions in an enclosed space, as well as the size and number of particles (i.e., contaminants) in the area. Strict guidelines and classifications are set by international standards for cleanrooms. For these reasons, when constructing a new cleanroom, it is critical to consider environmental conditions and requirements like temperature, ventilation and filtration, airflow, and air pressure.
Working with an experienced cleanroom contractor is the best way to ensure all systems are designed and installed correctly and that they function as intended.
Begin by analyzing workflow and patterns of movement within and into and out of the room (this includes people and equipment). These impact airflow, temperature and humidity, and particle or contaminant levels. Materials used for ceilings, walls, and flooring can also have an effect on airflow, dust accumulation, and moisture levels. All of this information is used to plan HVAC and filtration systems that create and maintain the right conditions when the room is at rest and in use.
Many systems and equipment can be used in a cleanroom to achieve the required conditions, and not all cleanrooms are designed and built identically. Some examples of the components that may be used in a cleanroom include:
- Air showers
- Air pressure monitoring equipment
- Airlock entry and exit systems
- Gown rooms, donning/doffing space, and storage for protective equipment
- HVAC systems
- Fans equipped with high-efficiency particulate air (HEPA) filters
- Sticky mats to trap particles on shoes or that fall from above
A new cleanroom is evaluated at three points during construction to ensure proper conditions can be maintained:
- As built, when construction is complete but equipment and machinery are not moved in yet.
- At rest, when all equipment and systems are installed but not yet operational.
- In operation, when employees and equipment occupy and use the room for regular operations.
Cleanroom Classifications
The current international cleanroom design standards are ISO Standard 14644-1. It sets nine classifications (i.e., ISO 1 through ISO 9), each designating positive pressure requirements and the allowable number of particles of different sizes per cubic meter within the room. Particle sizes are grouped into six ranges from ≥ 0.1µ to ≥5µ.
For example, an ISO class 1 cleanroom, the most “clean” environment, requires that there be no more than 10 particles ≥ 0.1µ per cubic meter and no particles larger than that at all. In contrast, an ISO class 7 cleanroom allows more particles of different sizes per cubic meter, resulting in a slightly less “clean” setting:
- No requirements for particles ≥ 0.1µ to ≥ 0.3µ
- Up to 352,000 particles ≥ 0.5µ
- Up to 83,200 particles ≥ 1µ
- Up to 2,930 particles ≥ 5µ
ISO 14644-1 standards are very similar to the former US Standard 209 requirements, which have not been in use since 2001.
Different applications and manufacturing processes must comply with different cleanroom classifications, and this plays a major role in the design and construction of the room. Some applications may have additional requirements, such as sterile drug compounding. This process is subject to USP chapter 797 requirements, which include limits on particle sizes and counts and sets air pressure requirements, along with guidance for equipment and personnel procedures.
Cleanroom Supplies from Liberty Industries
To learn more about the design and construction of cleanrooms, please download our free in-depth Understanding the Design & Construction of Cleanrooms guide here!
Since 1953, Liberty Industries has specialized in cleanroom equipment, supplies, and construction services for customers in a range of industries. We provide everything required for your cleanroom or contamination control applications from cleanroom design engineering to protective garments, and from airflow equipment to particle counters.
Contact us today to learn more about our capabilities or to discuss the requirements of your cleanroom application.
