Tim Sandle has written a new article
for Cleanroom Technology around the subject of cleanroom construction. A new
part of ISO 14644 – part 14 – came out last year which covers cleanroom equipment
specification. Tim Sandle looks at why it was introduced and its relevance for
those specifiying equipment for use inside cleanrooms.
Cleanrooms are designed to minimize the
ingress of airborne particles (achieved through HEPA or ULPA filters) and to control
what happens to particles generated within the cleanroom. Good air flow design
— such as turbulent flow — helps to prevent particles from being deposited onto
surfaces (particles settle by two primary mechanisms: gravitational sedimentation
and turbulent deposition). The removal of these particles is achieved through the
extraction of room air with the addition of clean air into the room (air exchange
rates). The flow of particles in air from a less clean area can also be blocked
from entering an area of a higher cleanliness level through positive pressure differentials.
The reference is:
Sandle, T. (2017) Applying design and
construction standards to cleanroom builds, Cleanroom
Technology, 25 (8): 16-18
Posted by Dr. Tim Sandle