What is the FFU?
What is FFU?
A Fan Filter Unit (FFU) is a relatively simple device consisting of a filter laminar diffuser, with an integrated fan and motor. The integrated fan is used to, instead of relying on the main air handling unit (AHU), provide sufficient static pressure to overcome the pressure drop of the attached HEPA or ULPA filters; therefore, by using an FFU system, the size of the AHU required can be significantly reduced.
Another benefit of using a decentralised system with multiple FFUs is the reduction in potential downtime. The loss of one FFU has a negligible effect on the overall system, whereas the loss of a central AHU can be extremely limiting.
FFUs are mainly used in microelectronics manufacturing facilities based on several key advantages: decentralised air handling, high airflow capacity and modularity, which allows individual units to be easily added or removed.
FFU Configuration Installation
1. Draws Air from a Common Duct
One of the main advantages of a common ducting FFU system is that it essentially converts the ceiling ducting into a negative pressure space, thus eliminating the risk of contaminants migrating from the ceiling ducting into the clean space below. Negative pressure is created by the FFUs drawing in ambient air from a common return air outlet as well as fresh outside air from the AHU. In this configuration, the FFU should be selected with a constant flow motor programme that automatically adjusts the motor torque and speed in an energy-efficient manner to overcome the rising static pressure as the filter load increases.
2. The FFU can be fed directly from the AHU or the end unit.
In this arrangement, the FFU and the upstream end device are directly coupled, so both devices must not attempt to actively control the airflow rate at the same time. If pressure-independent venturi valves or constant volume terminals are used to control the airflow rate, a constant torque motor programme should be selected for the FFU to ensure that the two systems do not work against each other to maintain a constant airflow into the space.
If the purpose of the ducted FFU is to maintain a constant airflow rate, the constant flow motor programme should be used in conjunction with an upstream manually balanced damper rather than a pressure-independent terminal. The pressure at the ducted FFU inlet must be as close to neutral as possible.
FFU Constructions
1. Fan equipment
Fan equipment is often used in various places, and there are many types of fan equipment; different fan equipment have different filtering requirements. However, no matter what type of fan equipment, FFU is designed according to the requirements of the fan equipment, which can achieve the ideal purification effect and ensure the operating performance and service life of the fan. Therefore, everyone should not ignore the effect of FFU when using a fan.
FFU is an important part of the fan. When using the fan, the user must regularly check and maintain the equipment to ensure that the FFU in the fan maintains a good performance for a long time and can meet the application requirements of the equipment.
2. Air conditioning equipment
FFU is also used in air conditioning equipment, which can be used as an end filter to efficiently purify the air and ensure that the air conditioner has the ideal performance. However, when consumers choose FFU, they must pay attention to the model and other information to ensure that the purchased FFU equipment meets the needs of air conditioners and assists the air conditioners to exert their ideal effects.
Air-conditioning applications must pay attention to the application of filter equipment. Because air-conditioning filters mainly purify the pollution in the air, the heating and cooling effect of the air-conditioning is better, and the service life of the air-conditioning is extended to meet the actual application needs of users. Here is a reminder: For long-term use of air conditioning, we must pay attention to the cleaning of the FFU to avoid affecting the application of air conditioning equipment.
