The difference between HEPA filter box and Fan filter unit (FFU)
Both Fan filter unit (FFU) and HEPA filter box are used in the the construction of cleanrooms as the key terminal air filtration equipment of air supply systems to meet the air purification requirements,are all widely used in purification air-conditioning systems in medicine, sanitation, electronics, chemical industry and other industries.But they are greatly defferent in the actual application and the product itself。Then what's the between HEPA filter box and Fan filter unit (FFU)?
Fan filter unit (FFU) is an self-powered device, is composed of housing,HEPA filter,fan and motor,which can be installed on the indoor ceiling or placed on a bracket.The fan filter unit sucks in the air from its top and passes it through inside HEPA filter.The filtered clean air is evenly sent out at a net speed of about 0.45M/S±20% on the entire air outlet surface，so don't need to be connected with air duct.
The FFU fan filter unit can adopts modular connection, mainly used in large clean rooms, which can conveniently realize on-site decentralized control and centralized and unified management functions. It can flexibly control the start, stop and speed regulation of FFU fans,it's mainly used in the clean rooms of Class 10 or Class 100,Class 1000 or others. And 4x4 Hepa Fan Filter Unit and 2x4 Hepa Fan Filter Unit are the most widely used type.
HEPA filter boxesare not equipped with fan and motor, it's just composed of housing,HEPA filter and air duct,and sometimes the air diffuser can be equipped,it's not a self-powered device.The HEPA filter box has an "air inlet" on the top or side, and the "air inlet" is connected to the MAU air-conditioning box through the air duct. The use position is located on the top of the clean room, and it is used in a turbulent flow clean room.The HEPA filter box normally are not used in the Class 10 and Class 100 clean room,but in the Class 1000,Class 10,000 or others.
Besides above difference,1) FFU can also be equipped with Primary filter or chemical filter to meet the requirements of different industry. 2) In terms of cost, the initial investment of HEPA filter FFU is higher than that of using HEPA box, but in the later operation, it highlights the characteristics of energy saving and maintenance-free, so the later operation cost is lower.
