Views: 0 Author: Site Editor Publish Time: 2025-04-25 Origin: Site
Cleanrooms often play a vital role in modern industrial, medical and research environments. In order to ensure that airborne particles, micro-organisms and contaminants are effectively controlled in a Clean Room, it is essential that airflow patterns are designed appropriately. So, what are the common airflow patterns in Cleanrooms? What are their characteristics?
Unidirectional flow, also known as laminar flow, is a pattern in which air flows smoothly in a single direction. The air usually flows from the top of the clean area to the ground, taking particles out of the air. This mode is often used in environments with extremely high cleanliness requirements, such as semiconductor production lines and sterile pharmaceutical workshops.
In unidirectional flow Cleanroom, FFUs (Fan Filtration Units) are often used, whereby the FFUs pass the outside air through their own inbuilt fans and HEPA filters, and then uniformly feed it into the clean space, ensuring that the air continues to flow in a unidirectional manner, reducing the risk of vortexes and the risk of contamination in dead-end areas.
Non-unidirectional flow, also known as turbulent airflow, refers to the way air circulates indoors in different directions and irregular movements. It relies on the air conditioning system to deliver air uniformly into the Cleanroom and then out through the return air outlets. This method cannot completely eliminate eddy currents, but it can control indoor particulate concentrations within permissible limits by increasing the number of air changes.
In this type of airflow pattern, a HEPA Box is often used, which is a high-efficiency filter box installed at the end of the air supply duct in the cleanroom to re-filter the air at the end of the supply duct to ensure that the air entering the Cleanroom meets the desired cleanliness level, while maintaining the stability of the airflow in the room.
Hybrid airflow combines the characteristics of unidirectional and non-unidirectional flow, usually with unidirectional flow in critical areas and non-unidirectional flow in peripheral areas. This ensures the cleanliness of the core operating areas while maintaining overall space flexibility and economy.
When choosing a cleanroom airflow pattern, it is necessary to consider various factors such as cleanliness level, usage scenarios, equipment arrangement and operating costs. For example:
Unidirectional flow or partial unidirectional flow mode is recommended for high class Cleanroom (like ISO 5).
Medium and low level cleanrooms can adopt non-unidirectional flow or mixed airflow design.
Thus, according to different project requirements, scientific and reasonable planning of cleanroom airflow pattern, in order to achieve efficient, stable and economic clean control.
