Every cleanroom is designed to uphold a certain cleanliness level and ISO classification — and a major component of meeting those standards is establishing and maintaining a proper airflow pattern. In fact ISO 14644-4 designates an entire annex section to discussing the necessary airflow patterns for maintaining low contaminant and particle counts. 

But what goes into achieving the right airflow pattern for your cleanroom? Below, we’ll provide an overview for how cleanroom airflow patterns are designed, and how you can ensure yours are meeting all necessary cleanliness requirements. 

TYPES OF CLEANROOM AIRFLOW PATTERNS

Cleanrooms employ a number of HEPA and/or ULPA fan filters in order to limit how many contaminant particles enter the clean environment. Generally speaking, the more filters installed, the more treated your cleanroom will be. However, HEPA and ULPA filters are also capable of creating different airflow patterns, which can also affect cleanliness levels. 

The two main types of airflow patterns are turbulent airflow and laminar airflow. 

TURBULENT CLEANROOM AIRFLOW PATTERNS

Turbulent, or non-unidirectional, airflow occurs when air flows in various currents throughout your cleanroom. It’s mostly commonly caused by non-uniform air speeds or obstructions in the air’s path. 

Turbulent airflow patterns can threaten the cleanliness of your environment. They can cause uncontrolled movement of contaminating particles, or they can cause dead zones where no air is moving — allowing those particles to build up over time. 

LAMINAR CLEANROOM AIRFLOW PATTERNS

Laminar, or unidirectional, airflow occurs when air flows in flat, uniform layers throughout your cleanroom. Typically, laminar airflow patterns follow a vertical path from the ceiling straight down to the floor. They require as little disturbances as possible in order to maintain a uniform pattern. 

Laminar, uniform airflow patterns are important in achieving the most controlled cleanroom environment possible. They work to keep particle movements consistent, and to prevent dead zones from popping up. 

HOW TO ACHIEVE CLEANROOM AIRFLOW UNIFORMITY

To achieve a uniform airflow pattern, you first need to install HEPA and/or ULPA fan filters in the ceiling of your cleanroom. Make sure you have the correct amount of fan filters for your desired level of cleanliness. Then, those filters will push treated air out vertically, downward toward your work surfaces and eventually to the floor of your cleanroom. 

An important step of ensuring airflow uniformity is to minimize, remove, or account for any factors that could cause turbulence. You can do this by designing your cleanroom airflow pattern to accommodate your layout, equipment, furniture, and personnel. 

Need some tips on how to accommodate each of these factors? Try some of these:

Ensure large equipment or furniture pieces aren’t blocking fan filter units

Adjust equipment with aerodynamic attachments or design features

Use perforated cleanroom tables to allow air to pass through uninhibited

Modify behavior of personnel to not block airflow within critical zones

THE BENEFIT OF EXPERT, CUSTOM CLEANROOM AIRFLOW DESIGN

As your cleanroom’s ISO classification becomes more stringent, hiring an expert to design your cleanroom airflow pattern becomes more critical. They have the tools and experience needed to design a layout that optimizes airflow to meet your requirements. 

In many cases, a custom cleanroom designer or engineer will use fluid dynamics to map out your cleanroom. Then, they’ll place fan filter units and outlets appropriately to meet necessary standards. This process allows them to visualize the airflow patterns and make adjustments for systems, equipment, furniture, and personnel in order to achieve uniformity. 

Whether you want to install your own cleanroom or have it installed professionally, your cleanroom airflow pattern is something you need done right. Kang Cleanroom can help! Our experts design every inch of your modular cleanroom before it’s built and delivered to you. We provide detailed instructions for installation in case you choose to DIY — but we also offer professional installation services to set it up quickly and effectively for the best possible results. Contact our team to learn more.