Basic Documentation

Room Pressurization Control Application Guide
Clean Rooms
Nearly all pharmaceutical, biomedical, microelectronics, as well as the optical industry and
many others, need to prevent contamination of their products or processes by maintaining a
clean room environment. In particular, the pharmaceutical and biomedical production facilities
require very careful room pressurization control to ensure against biological and chemical
agent contamination as a condition for meeting and maintaining regulatory (FDA)
compliance.
Microelectronics fabrication and electronic component assembly areas need a high degree of
environmental purity to prevent particulate contamination in the manufacturing process. As
microelectronic chips and data storage media continue to become more miniaturized while
providing greater processing power and data storage capacity, even the smallest airborne
particle could create an undesirable circuit-to-circuit bridge. Today’s microelectronic circuit
conductors are 100 times smaller in width than a human hair and use even smaller spacing
between conductors. These applications all require the most intensive form of contamination
prevention. As some components created by the micro electronics and optics industry
become even more miniaturized, contamination concerns extend down to the single
molecular level.
In all clean room applications, infiltration of contaminants from adjacent areas and the
outdoors (dust particles, pathogens, aerosols, etc.) is prevented by maintaining the clean
room space at a substantial positive pressure with respect to the surrounding areas. In many
clean room applications the surrounding areas are also positively pressurized in order to act
as buffer zones to help ensure against accidental contamination of the most critical areas.
8 Siemens Building Technologies, Inc.