Why Is Airflow Management Critical in Clean Room Environments?

Clean rooms are carefully engineered spaces with extremely low concentrations of airborne particulates. Manufacturers of pharmaceuticals, electronics components and other high-value, in-demand products are fabricated and handled in clean rooms to prevent contaminants from interfering with their performance. Airflow management is a significant part of maintaining effectively operating clean rooms. What should professionals know about clean room airflow principles?

Choose the Appropriate Clean Room Airflow Type

Airflow management professionals must choose between three airflow options for their clean rooms.

Unidirectional

Unidirectional systems move air in one direction, usually vertically but sometimes horizontally.  The action happens when air from fan filter units hanging from the ceiling blows into an exhaust system below. All air inlets and outlets are in parallel arrangements to enable a consistent airflow, minimizing the chances of contaminants affecting the room’s surfaces.

People must carefully design the room to achieve the appropriate layout and reduce the chances of insufficient airflow or turbulence. One issue with the latter problem is that it can degrade contamination control efforts by making equipment operate less efficiently. However, using laminar airflow hoods in clean rooms reduces turbulence. They feature material such as stainless steel, which will not contribute to the environment’s particulate matter count through shedding.

Airflow insufficiency can cause dead zones or air pockets where air moves too slowly. Contaminants can build up in them, which could be transferred to critical equipment.

Non-Unidirectional

Whereas the air in unidirectional clean room setups flows in one direction, it takes several paths in rooms with non-unidirectional airflow management, some of which may include routes around objects. Additionally, high turbulence, filtration and circulation maintain the necessary cleanliness.

Non-unidirectional strategies often result in the air forming a vortex shape, especially when clean air enters and mixes with what is already there. Although this involves filtration, the air movement is also a significant factor since its randomness and the quantity of air passing through the filters keep contaminants from reaching unsafe levels.

Mixed

Some clean rooms have critical areas — such as those associated with sensitive materials or components — over which laminar airflow hoods maintain unidirectional airflows. However, in the rest of the room, filters enable non-unidirectional airflow.

Professionals interested in adding these rooms to their facilities should carefully plan occupant levels, work tasks, and other specifics that impact the type and level of potential contaminants.

Airflow Management Depends on the Product’s Requirements

Although it is important for people to know about the three airflow types, they must also choose the right one based on the products made in the environment. There are nine cleanliness classes for clean rooms, each based on permissible levels of particulate contaminants. Additionally, each class generallyallows 10 times fewer than the one below.

For example, medical device and consumer electronics manufacturers most commonly choose Class 7 and 8 clean rooms. A Class 8 clean room allows 100,000 particles per cubic meter volume of air, but the permitted count is only 10,000 in a Class 7 environment.

Clean rooms also have specific required features at some levels. For example, those categorized as Class 7 or above must have positively pressurized entrances that stop particulate transmission into the environment. Additionally, all workers must enter gowning rooms to don the necessary equipment before entering the controlled environments.

Once leaders understand their products' specific clean room airflow requirements, they should strongly consider using industrial monitoring equipment to verify that the environment stays within the required parameters. It can also tell decision-makerswhich production aspects cause the most air quality challenges. That information can give them the information needed to behave proactively rather than facing situations where contaminants become poorly controlled due to low awareness.

Industry Specifics Dictate Clean Room Airflow Needs

People involved in maintaining the appropriate clean room airflow must also understand the industry specifics that could impact their work. For example, three fewer clean room classes existed under a previous framework called Federal Standard 209E. However, people in the United States and Canada now follow ​​ISO 14644-1. It indicates the decimal logarithm for particles measuring 0.1 microns or larger per cubic meter of air. However, there are additional specifics for some clean room classes.

In a Class 7 clean room, the particle concentration for those measuring 0.5 or larger must be below 352,000, and the room cannot have more than 83,200 particles of 1-4 microns. The particle count for those 5 microns and above must be below 2,930.

Staying familiar with the specific industry standards and regulatory requirements is the best way to prioritize safety and prevent recalled products, fines or other unwanted consequences caused by inadequate airflow management.

Technology Can Improve Awareness and Cause Improvements

Airflow management professionals should also consider how technologies could help them make strategic facility enhancements. Monitoring sensors are excellent for everyday awareness, but options exist to help people make meaningful choices at other times.

Parties involved in the construction of new factories or upgrades for existing ones may use digital twins to test various options before approving them. Such approaches could prevent costly errors or wrong assumptions regarding the type and placement of filtration equipment or other specifics.

Alternatively, people can run airflow visualization studies to verify they get the desired results based on the clean room’s setup. These tests involve introducing smoke or fog into the environment perpendicular to the airflow. Auditors watch its movement and see whether it lingers or becomes concentrated in particular areas. The associated reports can tell executives whether their facilities follow airflow management best practices or need improvements.

Exploring the latest advancements for clean room airflow is also valuable for showing people the possibilities. One example comes from a company with a solution that goes beyond keeping a room within preset ventilation parameters. It makes real-time changes based on contamination fluctuations in a clean room. That approach saves money and cuts emissions by increasing ventilation to the required areas.

Succeed With Airflow Management for Manufacturing Resilience

Maintaining appropriate clean room airflow is essential for production quality control, consumer safety and operating within regulatory requirements. People should understand the link between factory changes that could impact airflow or contaminant levels and require specific actions to combat problems.