Understanding 3 Key HVAC Systems in Cleanrooms: MAU, DCC & FFU

Clean Room, also known as “Cleanroom”, is an environment where temperature and humidity, cleanliness, room pressure, airflow velocity and distribution, noise and vibration, lighting and static electricity are strictly controlled.

The source of clean air in a clean room is Outside Air, which is processed by various air conditioning and filtration equipment in the clean room system to meet the cleanliness requirements of the clean room. There are three key equipment: MAU, DCC and FFU.

MAU(Make-up Air Unit)

The MAU (Make-up Air Unit), also known as the outside air conditioning unit, has the greatest impact on the clean room environment. Its main function is to control the dew point, create clean air and ensure positive pressure in the clean room. Clean rooms require fresh air at constant temperature and humidity, so fresh air must be extracted from the outdoors and passed through the MAU for dust removal, humidity control, and temperature control to adjust the air to meet the clean room’s needs and replace the existing air.

DCC(Dry Cooling Coil)

A DCC (Dry Cooling Coil) is a equipment that is used to control the temperature of a room and to remove all types of heat from the room. In a clean room, these include heat generated by people, lighting, machinery, etc. The DCC can be used with a MAU to provide a clean room solution.

The DCC can adjust the temperature of the airflow in the return air ducts in accordance with the air temperature provided by the MAU, which reduces the amount of chilled water needed to circulate the cooling coil and adjusts the heat load of the clean room at any time.

FFU(Fan Filter Unit)

FFU (Fan Filter Unit) is a filtration and air supply equipment made of HEPA (High Efficiency Particle Air Filter) or ULPA (Ultra High Efficiency Particle Air Filter) and a miniature air supply unit. It is commonly used in clean rooms with turbulence or laminar flow, and can be regarded as a self-contained end-of-pipe filtration and air supply equipment, which is widely applied in clean rooms.

In a clean room, MAU, FFU and DCC work together. The MAU is responsible for pre-filtering, primary filtering, humidification, dehumidification, cooling and heating of the outside air to filter and control the temperature and humidity of fine dust before sending it into the clean room’s recirculation ducts, while the DCC dry cooling coils further cool down the recirculation air in the recirculation ducts to meet the requirements of the clean room. The FFU then filters the air with ultra-high-efficiency filters and circulates the air in the clean room, removing fine dust and heat to achieve the desired cleanliness and air exchange. Eventually, the clean air is supplied back to the manufacturing area (Fab) in the clean room.

By using a combination of MAU, DCC and FFU systems, you can ensure that the environment in your clean room meets the required cleanliness standards. Understanding how these equipment work and their features can help us to better operate our clean rooms and achieve a high quality production working environment.