FFU is a device used in cleanrooms and other particle-controlled environments like laboratories, healthcare facilities and manufacturing plants to maintain a high level of air cleanliness and particle control. FFUs are typically installed in a grid pattern on the ceiling of a cleanroom to provide a continuous flow of clean and filtered air from above. This downward laminar airflow helps maintain a controlled and clean environment by preventing airborne particles from settling on surfaces or contaminating sensitive processes or products. They are known for their energy efficiency and ease of installation, making them a popular choice in particle-controlled environments