Q：What are advantages and disadvantages of one HEPA combining with forced draft fan (FFU)?

A：Advantages: ① In established space of common air conditioners, FFU with clean shed is added to increase cleanliness, which is compact and convenient.
②It makes up the short air from main AHU.
③It can be used with common AHU.。
Short comings：①Disadvantages: In clean room of unidirectional flow, in case of part failure, 「non-unidirectional flow」 will occur and cause major impact on cleanliness
②Setup of air outlet display below air outlet (Or tie to a string) is recommended to find faulty unit in a timely manner.
③In the place where inner height of the ceiling is insufficient, clean maintenance is not easy.
④It necessitates higher height of ceiling.