Cleanrooms are designed for conducting research or manufacturing in extremely clean environments. And, in critical environments, the cleanliness relies heavily on airflow.

Creating and maintaining the perfect cleanroom is no easy task. You need to meet hefty standards, such as ones directed by the FDA. Additionally, you need the room and your scientific equipment consistently tested and certified.

Failing to maintain uniform airflow and velocity can negate your clean environment. As part of our Standard Operating Procedures, our services include testing of airflow volume, velocity testing, room air changes, and more.


Types of Cleanroom Airflow

Depending on your cleanliness needs and the size of your facility, you will need a different airflow. Additionally, we recommend assessing factors such as amount of personnel, quality of cleanroom garb, and amount of entries/exits.

Cleanrooms use air filtration to limit particles contaminating the air. Generally, the filter used is a HEPA filter, which stands for “highly efficient particulate air”.

Laminar Air Flow

Laminar airflow means thats the air is uniformly supplied in one direction. Typically, the airflow direction is vertical.

Cleanrooms in the ISO-1 to ISO-5 classes will rely on laminar airflow, as it is most effective in limiting contamination.

The unidirectional flow is maintained by laminar airflow hoods. In addition, the cleanroom structure will contribute to keeping the airflow unidirectional.

Turbulent Airflow

Turbulent or non-unidirectional airflow is sufficient for class ISO-6 and above cleanrooms. The air will not be regulated for direction or speed.

Swirling air will allow particles to move around, rather than flow down and out like the rigorous laminar airflow system. Industries that do not need higher classes of cleanrooms will find turbulent airflow sufficient. Moreover, pressure-controlled areas can be used to supplement the clean room for specific activities.

Cleanroom graphic showing airflow and pressure direction

Pressure Controlled Environments

Clean spaces can be created for performing specific tasks. These pressure controlled environments protect the samples or materials, as well as the workers using them. For these reasons, air pressure is a vital component of a cleanroom.

The defining characteristics of pressure is high or low. Depending on the application, you may need a positive or negative pressure workspace.

However, it is possible to have high/low pressure vary within your facility. For instance, you may have an ISO-7 cleanroom with an ISO-4 laminar flow unit for certain operations. By assessing your lab needs, we can help determine the type of cleanroom or equipment to satisfy regulations and preserve your end-product.

Positive Pressure Cleanrooms

Positive pressure will prevent contaminated air from entering clean areas. Lower pressure air is less likely to contaminate the air do to the high pressure of the cleanroom.

In some cases, multi-chamber cleanrooms are designed with varying pressures. The room that needs to be the cleanest will be held at the highest pressure. The filtered air will flow from the cleanest to less clean spaces.

Positive pressure is used for things such as creating drugs or other substances for human consumption. They are clean and contaminant-free environments.

Negative Pressure Cleanrooms

A negative pressure cleanroom will pull more air out than what is entering, leading to a low-pressure environment. Following regulations of bio safety levels (BSL), negative pressure ensures that any hazards are controlled within the room.

In some research activities, limiting outside contamination is less important than exposing people to the sample. For this circumstance, a negative pressure room will provide safety to the personnel and surrounding area.

Inspection testing and certification Air velocity, airflow volume and room air change rate - Cleanroom Testing & Certification