Ventilation System

The ventilation system of a clean room is one of its most important components. This system is designed to keep the air moving and reduce particles and other contaminants in the air. Through an efficient ventilation system, unclean air can be expelled and fresh, filtered air can be introduced. This design ensures the air quality inside the clean room, providing the necessary environmental safeguards for precision manufacturing and research activities.

Filters

The filters in a clean room are critical to ensuring the cleanliness of the air. Common filters include HEPA (High Efficiency Particulate Air) and ULPA (Ultra High Efficiency Particulate Air). These filters capture and remove minute particulate matter, ensuring that airborne particulate matter is maintained at an acceptable concentration level.

Air Quality Control

Cleanrooms typically use negative or positive pressure systems to control air quality. A negative pressure system maintains the indoor air pressure lower than the outside world, preventing the entry of contaminated air from the outside; on the contrary, a positive pressure system maintains the indoor air pressure higher than the outside world, avoiding the spread of internal air contamination to the outside. This design helps maintain a relatively closed and clean environment.

Clean Clothing

Operators working in a clean room are often required to wear special clean suits, including helmets, face masks, gloves and specialized clothing. This equipment minimizes contamination from personnel and maintains the cleanliness of the cleanroom.

Preparation before installation

Before installing an FFU in the top of a clean shed, the clean shed must be thoroughly cleaned and wiped to ensure that the inside of the purified air conditioning system is free of dust. If a high-efficiency filter is to be installed in a technical mezzanine or suspended ceiling, the technical mezzanine or suspended ceiling also needs to be thoroughly cleaned and wiped.

FFU system testing

After the clean booth and FFU system have met the cleaning requirements, the FFU system should be tested. After 12 hours or more of continuous operation, clean the clean room again and immediately install the FFU matching high-efficiency filter.

Transportation and storage of FFU high-efficiency filter

The transportation and storage of FFU high-efficiency filters should be carried out according to the direction of the manufacturer's instructions. During transportation, it should be held lightly to prevent violent vibration and collision.

Inspection before installation

Before installing FFU high-efficiency filter, the package should be unpacked and inspected at the installation site, including whether the filter paper, sealant and frame are damaged; whether the side length, diagonal and thickness dimensions are in accordance with the requirements; whether there are burrs and rust spots on the frame (for metal frames); whether there is a certificate of conformity of the product, and whether the technical performance is in accordance with the design requirements. After that, check whether there is leakage, and those qualified by inspection and leakage detection should be installed immediately.

Allocation of filter resistance

The installation should be reasonably allocated according to the resistance of each filter. For unidirectional flow, between the filters of the same air outlet or air supply surface, the difference between the rated resistance of each filter and the average resistance of each filter should be less than 5%.

The Importance of Clean Rooms

Clean rooms are widely used in industries such as semiconductor manufacturing, biomedical, and food processing, where the control of contaminants such as particles, microorganisms, and chemicals is particularly critical. As a result, the testing of clean rooms has become a key part of ensuring product quality.

Testing Standards

The cleanliness of a clean room is usually measured in terms of particle counts per cubic meter (PCM) or per cubic foot (PCF). This is regulated in detail by the Chinese standard ISO 14644 and the U.S. Federal Standard 209E. For example, the ISO 14644-1 standard specifies particle count limits for different cleanliness levels.

Testing Programs

Testing programs for clean rooms include, but are not limited to, temperature, humidity, airborne particles, fresh air volume, differential pressure, and airflow conditions. These tests are essential to ensure the environmental conditions in the clean room.

Testing Process

The testing process of a clean room usually includes on-site sampling, laboratory testing, and issuance of a test report. The testing period is usually 7 working days.

Testing Equipment

Commonly used testing equipment includes particle counters, differential pressure meters, anemometers, air volume hoods, noise meters, illuminance meters, temperature and humidity meters, etc.