Cleanroom Classification Assessment as per ISO 14644-1

Air Particulate Concentration Levels

Cleanroom classification is an essential part of the qualification activities in Data Center and other associated critical facilities.

There are two types of airborne contaminants that most data centers have to contend with: solid particles and gases. Even with a physical separation of equipment in a data center, industrial processes can produce unacceptable levels of particulate contamination.

Particulate contaminants can impact the sustained operations of computer hardware. Effects can range from intermittent interference to actual component failures. Therefore, airborne contaminants should be maintained within defined limits to help minimize their potential impact on the hardware by regularly scheduled decontamination.

ISO 14644-1 cleanroom classification

ISO 14644 cleanroom classification is now the accepted worldwide standard for classifying the cleanliness of the air in cleanrooms and clean zones.

ISO 14644 states contamination levels as the maximum number of particles per cubic meter of air in six distinct sizes. Permitted concentration of particles for each considered particle size is determined from threshold sizes defined by the standard. Air cleanliness class by particle concentration is designated by an ISO Class number.

Recommended Air Particulate Concentration Levels

Cleanrooms operate at different classes of cleanliness depending on what their purpose is. The lower the ISO Class, the fewer particles in the room and, consequently, the cleaner the room is. Most cleanrooms like those used in medical device manufacturing or the aerospace industry are ISO Class 5 to 8.

ASHRAE recommends that Data Centers should be kept clean to ISO Class 8.