Cleanrooms are used for many different processes ranging from the production of medications to creating microchips. Although the cleanrooms look similar to normal rooms with features like walls and doors, they are actually quite different. One of the main differences that set cleanrooms apart from other rooms has to do with airflow.
In a standard office, HVAC units typically produce two to ten changes of air per hour. In a controlled environment like a cleanroom you expect to see 20 to upwards of 600 air changes per hour. This means much more air is being moved in the cleanroom which is designed to combat particulates and contamination.
Cleanrooms require a high volume of air which is usually pushed through the HEPA, or high efficiency particle air filters. You’ve probably seen these filters before in your vacuum or car, and the ones in the cleanroom work in the same way. HEPA filters are meant to capture particles before they enter the cleanroom. For some cleanrooms that require a very high standard of cleanliness, ULPA (ultra low particle air) filters which add an enhanced level of air purification.
The air in the cleanroom passes through the HVAC and flows down into the cleanroom. There are several different types of airflow in a cleanroom, although laminar flow is the most common. The air flows down from the ceiling in flat layers. From here the air reaches the ground and is then captured through floor level grilles where the cycle is started all over again. Some rooms that have positive or negative pressure may require additional equipment to add additional clean air to the cleanroom.
The surfaces in a cleanroom are quite different than those found in standard rooms. In an environment that needs to be cleaned quite frequently, the surfaces in a cleanroom are designed not to emit particles, as well as being easily cleaned. This includes smooth surfaces and avoiding a design with excessive cracks and crevices..
In addition to airflow and easily cleaned surfaces, cleanrooms may employ specialized entryways and air showers. Like the air filters, these are additional means to keep particulates out of the cleanroom and not contaminate the room. Those who work in cleanrooms usually wear some type of protective clothing that may range from gloves all the way to a fully protective suit
In conclusion, cleanrooms are controlled environments that are continually waging war against particulates. Specialized HVAC units, HEPA filters and air showers all help keep the environment clean and in working order.