FFU, abbreviated as Fan Filter Unit, is professionally referred to in Chinese as an air purifier. The FFU air purifier can be modularly connected for use, and is widely applied in clean rooms, clean benches, clean production lines, modular clean rooms, and local 100-level applications. The FFI is equipped with primary and secondary filtration nets. The fan draws in air from the top of the FFU and passes it through the primary and filter, then the filtered clean air is uniformly discharged across the entire outlet at a velocity of 0.45 I/S ± 20%. It is suitable for obtaining a clean environment in various environments. It provides high-quality clean air for clean rooms and micro-environments of different sizes and cleanliness levels. In the construction or renovation of new clean rooms or clean factory buildings, it can enhance the cleanliness level, reduce noise and vibration, significantly lower construction costs, and is convenient for installation and maintenance, making it an ideal component for clean environments. Field tests have shown that international brands often struggle to adapt to "Chinese environmental factors," and although their quality is generally higher than domestic companies, stability tests after one year are often unsatisfactory; conversely, the engineering quality of most domestic low-end brands is also rather disappointing. In recent years, the purification engineering industry has started to focus on the dual standards of product quality and stability, and has gradually adopted field testing data (previously relying on industry reports) to more authentically reflect the cost-effectiveness of the project, which has far surpassed international brands and set a new international standard for Chinese FFU enterprises.