Cleanrooms and equipment

What is the main reason the air pressure inside a cleanroom is kept higher than its surroundings (positive pressure)?

  1. ATo raise the oxygen concentration in the room
  2. BTo reduce noise
  3. CTo keep dirty air from entering from outside
Show answer and explanation

Answer: C. To keep dirty air from entering from outside

With positive pressure, air flows from inside to outside when doors open and through gaps, making it hard for dirty outside air to enter. Rooms with higher cleanliness are given higher pressure so that air flows toward less clean areas.

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More Cleanrooms and equipment questions

  1. Which is a major source of particles in cleanrooms, addressed by wearing cleanroom suits?
  2. Which term refers to gaseous contaminants (acids, bases, organics, etc.) rather than particles in a cleanroom?
  3. In 300 mm wafer fabs, which system automatically transports FOUPs between tools along rails on the ceiling?
  4. Which facility at a cleanroom entrance blows strong jets of clean air at workers to remove dust from the surface of their clothing?
  5. What is the main reason temperature is held extremely constant in cleanrooms, especially in exposure areas?