Airflow & ventilation in cleanrooms
The Role of Airflow in Cleanroom Cleanliness
In cleanrooms, airflow and ventilation systems play a critical role in maintaining the desired levels of cleanliness by controlling the movement of air and filtering out contaminants.
The way air flows through a cleanroom directly impacts the room’s contamination control, which is crucial for sensitive production processes.
Cleanrooms are typically classified based on the type of airflow system they use, and the level of contamination control they require.
There are two primary types of airflow systems used in cleanrooms. See below:
Non-Unidirectional Airflow Cleanroom
In non-unidirectional airflow cleanrooms, clean air is supplied through HEPA or ULPA filters, usually installed in the ceiling. The fresh, filtered air mixes with the room air and dilutes or removes airborne contaminants generated by personnel, equipment, or processes. The contaminated air exits the room through low-level air extractors, typically located near the bottom of the walls. This creates a consistent circulation pattern where the air is constantly being refreshed, although the flow is not unidirectional.
Typical Classification Levels
Non-unidirectional airflow systems can achieve cleanliness levels up to ISO Class 6, depending on the size of the room and the processes being conducted.
Alternative Configuration for Lower Classifications
For ISO Class 8 cleanrooms, less stringent air control may be sufficient. In these cases, air extractors can be placed in the ceiling as opposed to the walls.
Ideal Use Cases
This ventilation method is ideal for cleanrooms that require moderate control over airborne contamination but do not demand the highest levels of particle control.
It is a more cost-effective solution compared to unidirectional airflow systems, making it a versatile option for industries such as pharmaceuticals, biotechnology, and food processing.
Unidirectional Airflow Cleanroom
Unidirectional airflow cleanrooms use a more sophisticated ventilation system to ensure high levels of air cleanliness.
In this system, high-efficiency HEPA/ULPA filters are installed throughout the ceiling. The air is swept vertically into the room unidirectionally and exits through the floor, effectively removing airborne contaminants and ensuring the environment stays as clean as possible.
High Airflow and More Filters
Since unidirectional airflow cleanrooms require more airflow and filters, they tend to be more expensive than non-unidirectional systems.
However, they provide much higher air cleanliness and are capable of meeting more stringent cleanroom classifications.
Compliance with Stringent Classifications
Unidirectional airflow systems can comply with highly stringent classifications such as:
ISO Class 5, ISO Class 4, ISO Class 3, ISO Class 2, and the most stringent level, ISO Class 1.
These cleanrooms are typically used in industries where the highest level of contamination control is required, such as in
pharmaceutical production, semiconductor manufacturing, and biotechnology research.
Key Differences Between Non-Unidirectional and Unidirectional Airflow Systems
See table below
| Feature | Non-Unidirectional Airflow | Unidirectional Airflow |
|---|---|---|
| Airflow Pattern | Mixed airflow (lturbulent) | Unidirectional airflow (vertical or horizontal) |
| Filtration | HEPA/ULPA filters in the ceiling | HEPA/ULPA filters throughout the ceiling |
| Contamination Control | Moderate control of airborne particles | High control of airborne particles |
| Typical Classifications | Up to ISO Class 6 | ISO Class 5 and more stringent classes |
| Ideal For | Moderate control, cost-effective for various industries | High-precision applications requiring strict contamination control |
Why Cleanroom Ventilation Matters
Ventilation is essential to cleanroom performance. The airflow system directly impacts:
Contamination Control
The ability of the airflow system to remove particles from the air ensures that cleanrooms maintain their intended cleanliness levels.
Temperature and Humidity Regulation
The ventilation system plays a role in maintaining the correct temperature and humidity levels, which is crucial for sensitive materials and equipment.
Product Integrity
For industries like pharmaceuticals and electronics, the proper air circulation prevents contaminants from damaging products, ensuring they are manufactured according to the required standards.
Contact Me for Cleanroom Ventilation Guidance
Choosing the right airflow system and ventilation design for your cleanroom is critical to maintaining a controlled environment.
If you have any questions or need assistance with understanding which ventilation system is right for your industry and requirements, feel free to reach out.
I am here to help you navigate the best cleanroom solutions for your specific needs, ensuring that your cleanroom operates efficiently and meets industry standards.
Contact me today to learn more about cleanroom ventilation systems and how to optimize airflow for your cleanroom!