The Importance of Clean Room Air Filters

Clean Room, also known as “cleanroom”, is an environment where temperature and humidity, cleanliness, room pressure, airflow velocity and distribution, noise and vibration, lighting and static electricity are strictly controlled. It is an environment where the temperature and humidity, cleanliness, pressure, air velocity and air distribution, noise and vibration, lighting and static electricity are strictly controlled, and is used in industries that are particularly sensitive to environmental cleanliness, such as semiconductor production, biotechnology, biotechnology, precision machinery, pharmaceuticals, food and hospital operating rooms.

Clean Room Grades

The smaller the value, the higher the level of cleanliness.

  1. ISO 1-3: This is the highest level of clean room, representing no more than 1 particle per cubic foot of air, and is suitable for extremely stringent applications such as micro lenses, wafer fabrication plants, optical components, and other semiconductor industries.
  2. ISO 4-5: This is the higher class of clean room, representing no more than 100 air particles per cubic foot, and is suitable for the production of medical products, electronic products, medical and aviation industries.
  3. ISO 6-7: This is the medium class clean room, representing no more than 10,000 airborne particles per cubic foot, and is suitable for the manufacture of food products, printing products and automotive parts. 4.
  4. ISO Class 8: This is the lowest class of clean room, representing no more than 100,000 particles per cubic foot, and is suitable for general manufacturing and production processes.
Cleanrooms grades
applications of cleanrooms

Introductions of Clean Room Filters

Air filters play an important role in keeping tiny airborne particles out of the clean room. Depending on the level of the clean room and the application requirements, the choice of filter will also vary, and the combination of Primary Filter + Secondary Filter + High Efficiency Filter or Primary Filter + High Efficiency Filter is usually used. Although high efficiency filters can also filter large size particles, it will quickly shorten the life of the filter, and the cost will also increase. Therefore, using a lower grade filter for larger particles and allowing the high efficiency filter to focus on smaller particles is the only way to save money on consumables.

The choice of filter has a great impact on the effectiveness of the clean room. When selecting primary, secondary and high efficiency products, different application scenarios and filtration requirements need to be considered. The following are some of the most common clean room filter options:

  1. Primary FilterThe primary filter is installed in front of the main filter, which can capture larger particles, reduce the dust capacity of the main filter and extend its service life. The Primary Paper Frame Filter is one of the common filters, which can effectively filter particles from 3 to 10 microns, but it is less effective in filtering tiny particles smaller than 3 microns in diameter. The Primary Metal Filter can be washed or cleaned with water, and has a longer service life, but care should be taken to avoid deformation or damage to the filter. The primary filter is suitable for frequent replacement and can be replaced easily and quickly to maintain the cleanliness of the clean room.
  2. Secondary Filter: Bag Filter is a kind of sub-high efficiency filter, composed of several bags, which can effectively filter tiny particles larger than 1~3 microns in diameter, and has a longer service life. ASHRAE Ultra Sonic Synthetic Bag Filters and ASHRAE Synthetic Rigid Cell Filters are also common secondary filters, which can effectively filter tiny particles with diameter larger than 0.5~1 micron and are usually used in occasions with higher requirements for cleanliness.
  3. High Efficiency Filter: HEPA (High Efficiency Particulate Array) filter is used in clean rooms of ISO 5 or above, which can effectively capture microorganisms and bacteria and other particles. HEPA Mini-pleat Filters can effectively filter tiny particles with a diameter greater than 0.3~1 micron, and its filtration efficiency is 99.99%, which is the first choice for high cleanliness requirements. In addition, Ducted Terminal ModulesHEPA High Temperature Separator Box Filters and HEPA HV(High Volume) V bank Filters are designed for different applications and are commonly used in Fan Filter Unit(FFU).

In addition to choosing qualified air filters, it is also important to note that the greatest source of pollution in a clean room comes from the users themselves, so those who work in clean rooms need to be thoroughly educated and trained in pollution control theory. When entering and leaving the clean room, workers need to wear clean clothes through the shower to ensure that contaminants and other particles naturally produced by the body and skin do not enter the clean room. In addition, as the operation time grows, the debris and protective coatings from the processing equipment or machines in the clean room may start to fall off and be released into the air, which is a source of pollution that is often overlooked.

The importance of clean room filters should not be overlooked. Choosing the right class of clean room and the appropriate filter can ensure efficient operation of the clean room and reduce the impact of contaminants on product quality, health and safety and productivity. However, when selecting and using filters, it is also necessary to pay attention to factors such as filter efficiency, replacement intervals and installation locations in order to ensure the stable operation of the clean room.