Cleanroom Air Filtration
Cleanrooms are facilities designed for conducting research or manufacturing products that require extremely clean environments. Typically, cleanrooms apply a broad range of techniques to prevent air particles, bacteria, and other contaminants from entering the workspace. However, one of the major forces keeping a cleanroom particle free is the air filter system. Cleanrooms apply many different types of filters, including HEPA filter and ULPA filter according to the efficiency the cleanrooms may need to reach, there one one standard air flow pattern that is consistently used laminar flow.
Cleanrooms are necessary for various kinds of scientific research and experiment that require particle- and bacteria-free environment. For example, when scientists grow cultures, it is important to reduce the introduction of other bacteria so that results will not be compromised. Manufacturing various kinds of products like microprocessors also requires particle-free environment, because even a human hair contacting the small chips of a microprocessor can inhibit or destroy functionality.
Cleanrooms are graded depending on how clean the air in the facility is. Usually there are two standards used for this determinationall over the world: the ISO and United States federal standards.Because people often work in cleanrooms, they are required to follow dress and behavior guidelines to limit the amount of particles they will bring into a cleanroom or particles they will shed while working in the environment. Workers must change from street clothes into specially designed outfits, often with full hood coverings, gloves, and breathing masks. Workers must also enter through an air shower to eliminate remaining particles on the cleanroom suit, and then pass items into the cleanroom through a small chamber that prevents outside air from entering the clean environment.
Cleanroom Air Filtration
Cleanrooms employ air filtration to limit the particles in the environment air. Typically, this is through the use of either a highly efficient particulate air (HEPA) or ultra low particulate air (ULPA) filter. These filters can remove roughly 99.9 percent of all microparticles in room air by applying either laminar air flow or turbulent air flow techniques to the environment air.
Laminar air flow refers to air that flows in a straight, unimpeded path. Unidirectional flow is maintained in cleanrooms through the use of laminar air flow hoods that direct air jets downward in a straight path, as well as cleanroom architecture that ensures turbulence is lessened. Laminar air flow utilizes HEPA filters to filter and clean all air entering the environment. Laminar filters are often composed of stainless steel or other non-shed materials to ensure the amount of particles that enter the facility remains low. These filters usually compose roughly 80 percent of the ceiling space. Cleanrooms employing laminar air flow are typically referred to as Unidirectional Airflow Cleanrooms.