Cleanrooms are used for a variety of processes from the production of pharmaceuticals to the manufacture of microchips. Although clean rooms look similar to regular rooms with features such as walls and doors, they are actually quite different. One of the main differences that distinguish clean rooms from other rooms has to do with air flow.
In a standard office, the HVAC unit typically produces two to ten air changes per hour. In a controlled environment such as a clean room, you would expect 20 to 600 air changes per hour. This means more air is moved in a clean room designed to combat particulate matter and contamination.
Cleanrooms require a high volume of air which is usually pushed through a HEPA, or high-efficiency particulate air filter. You’ve probably seen this filter before in a vacuum or your car, and the filter in a clean room works the same way. The HEPA filter is intended to capture particles before they enter the clean room. For some clean rooms that require very high standards of cleanliness, the ULPA (Ultra Low Particle Air) filter adds an even better level of air purification.
The air in the clean room passes through the HVAC and flows down into the clean room. There are several types of airflow in a clean room, although laminar flow is the most common. Air flows down from the ceiling in a flat layer. From here the air reaches the ground and is then captured through the floor grille where the cycle starts all over again. Some rooms that have positive or negative pressure may require additional equipment to add additional clean air to the clean room.
Surfaces in clean rooms are very different from those found in standard rooms. In environments that require frequent cleaning, the surfaces in the clean room are designed to emit no particulate matter and are easy to clean. This includes smooth surfaces and avoiding designs with excessive cracks and crevices.
In addition to airflow and easy-to-clean surfaces, clean rooms can use dedicated entrances and air showers. Like air filters, they are an additional means of keeping particles out of the clean room and not contaminating the room. Those who work in clean rooms usually wear some type of protective clothing which may range from gloves to full protective clothing
In conclusion, a clean room is a controlled environment that is constantly at war with particles. Dedicated HVAC units, HEPA filters and air showers all help keep the environment clean and functioning properly.