What is Downflow?
A cleanroom airflow method that sends clean air in one direction from the entire ceiling to the floor, quickly carrying generated particles away under the floor.
Field: Cleanrooms and equipment
Downflow in the explanations
In the downflow method, air blown from ceiling filters is drawn through the perforated floor into the underfloor space, then returns to the ceiling through side passages and the like to recirculate.
In downflow cleanrooms, why are perforated floor panels (gr…In downflow cleanrooms, a slow unidirectional airflow of about 0.3–0.5 m/s flows from the ceiling.
What is a typical guideline for the air velocity blown from…Downflow cleanrooms blow air from the entire ceiling at about 0.3 to 0.5 m/s, so a room a few meters high works out to several hundred air changes per hour.
In a high-cleanliness downflow cleanroom, which is closest …
Questions that mention Downflow (5)
- What is the main purpose of the downflow method, in which air flows in one direction from ceiling to floor in a cleanroom?
- In downflow cleanrooms, why are perforated floor panels (gratings) used?
- What is a typical guideline for the air velocity blown from the ceiling in downflow cleanrooms?
- In a high-cleanliness downflow cleanroom, which is closest to the typical number of times the room's air is replaced per hour (air changes per hour)?
- What is the role of the thick concrete floor with a grid of holes (waffle slab) used in fab cleanrooms?
Related terms
Airborne molecular contamination (AMC) EFEM FFU (fan filter unit) FOUP HEPA filter ISO 14644-1 Mini-environment OHT (overhead hoist transport) ULPA filter