Displaying items by tag: classification
Cleanrooms are classified according to the number and size of particles permitted per volume of air. Large numbers like "class 100" or "class 1000" refer to FED-STD-209E, and denote the number of particles of size 0.5 µm or larger permitted per cubic foot of air. The standard also allows interpolation, so it is possible to describe, for example, "class 2000".
As-build - A clean room that is complete and ready for operation, with all services connected and functional, but without production equipment or personnel in the room.
Operational - A term used to describe a clean room in normal operation with all services functioning and with production equipment and personnel present and performing their normal work functions.
One of the most important factors that you have to determine when constructing a cleanroom is what size of particle you will need to filter out. Is it any size particle? Is it a specific size or range of particles? Most often you find that people look at the cleanroom classification and they go to the lowest level particle count to determine what classification they need.
Every time you go down a class, or up a class, for instance from an ISO 8 (class 100,000) to an ISO 7 (class 10,000), that’s going to take twice as much air. The cost of filtering and moving air is a significant cost of operating a clean room. This process translates all the way down through to the number of filters that you need, the amount of return air space that you need, the amount of air conditioning you need to cool that return air and so forth. And this multiplies itself as you go through the process.
Everything depends on the amount of air cleanliness that is required; the number of filters you need, the amount of CFM that you need – everything is a result of that decision. Therefore, that decision sets the tone for every other decision that has to do with designing and constructing a clean room. And it adds the cost up front, as well as the operational cost.
There are a lot of determining factors involved in choosing a cleanroom classification and every industry has a default standard to start with. In medical device packaging for instance, the default classification is ISO 7 (or a class 10,000) cleanroom.