WHAT IS A CLEANROOM?
A cleanroom is basically a controlled environment that has the minimum level of pollutants such as dust particles, airborne microbes, aerosol particles, and chemical vapors. A cleanroom has an exact minimum level of contamination, that depends upon the size of the particles and the number of the particles per cubic meter.
WHERE ARE CLEANROOMS USED?
Cleanrooms are practically used by many industries where the contamination in the air can adversely affect the manufacturing process. For instance, cleanrooms are used in pharmaceutical industries, bio-medical industries, semi-conductor manufacturing industries and medicine manufacturing industries. It is highly necessary to control the contamination or the number of dust particles in the environment in order to carry out critical manufacturing processes.
CHARACTERISTICS OF AN ISO 8 CLEANROOM
Cleanrooms are characterized by their classes and by the number of particles it can trap from the air. Each class has its own characteristics. The three main characteristics of an ISO 8 cleanroom which differ it from the other classes are:
ALLOWABLE PARTICLE COUNT FOR ISO 8
ISO 1 traps the most particles from the air while ISO 9 represents a standard room. Most of the cleanrooms are constructed using ISO 3 to ISO 8. ISO 8 cleanroom allows greater number of particles in the air than the previous ISOs. ISO 8 is of class 100,000. Which means that, it allows for the highest concentration of particles for a particular cleanroom.
- If the size of the particles range from 0.1 micrometers to 0.3 micrometers, ISO 8 allows a higher volume of particles per cubic meter, for a cleanroom.
- If the size of the particles is less than 0.5 micrometers, ISO 8 allows only 3,520,000 countable particles for a cleanroom.
- Only 832,000 particles per cubic meter are allowed if the size of the particles is equal to less than 1.0 micrometers.
- If the size of the particles is 5.0 micrometers, ISO 8 allows only 29,300 particles per cubic meter for a cleanroom.
AIR CHANGES PER HOUR
The key component in a cleanroom is a High Efficiency Particulate Air (HEPA) filter that is used to trap the particles. This filter varies from class to class. ISO 3 requires the maximum air changes per hour while ISO 8 requires the minimum air changes per hour. Typically, an ISO 8 cleanroom requires 15-25 air changes per hour if the air flow is non-unidirectional. But this factor mainly depends upon the cost of construction, size of the room, number of users, type of processes in the room and the types of equipments in the room.
While planning to construct a cleanroom project, it is important to know about the cleanroom space, layout of the space, number of anticipated users, number of equipments and the types of manufacturing processes that would be carried out in an ISO 8 cleanroom. If you want to switch from ISO 9 to ISO 8, you can do it directly, without an airlock. Some cleanrooms have gowning rooms, depending upon the manufacturing processes.
Cleanrooms are becoming a necessity, where industries can carry out critical manufacturing processes. Cleanrooms allow minimal interference with the critical manufacturing processes by limiting the number of particles per cubic meter.