What is a BFU fan filter unit?

BFU is the abbreviation of Blower Filter Unit, which usually refers to a clean air supply unit that combines a blower/Fan with a filter.

Its basic function is:

The air is sucked into the equipment → powered by the fan → passes through the high-efficiency filter → enters the clean space through the air supply structure.

Compared with using a filter box alone, BFU combines power and filtration functions in one equipment unit; when used in conjunction with a central air conditioning system, the air duct connection method can also be used according to the project structure.

Some BFU adopt a self-circulation structure, which directly returns air from the clean room and is filtered before being sent into the room again; another type is connected to the air duct system and the air is provided by the external air conditioning system.

Therefore, the BFU is not a single fixed structure, but a modular device that can be configured according to the cleanroom system, installation method and air treatment needs.

Depending on the air source, the BFU can adopt different structures

A｜Self-circulating BFU

Clean room air → BFU return air → Fan → HEPA / ULPA → Clean air is returned to the room

This structure is suitable for applications that require continuous air circulation inside a clean space.

B｜Duct connection type BFU

Air conditioning system → air duct → BFU → filter → clean room

This method can be combined with central air conditioning or clean room air conditioning system and designed according to the project air volume and static pressure conditions.

Why do clean rooms use BFU? ——What clean air treatment needs is BFU suitable for?

There is not necessarily just one way to handle air in a clean room.

For some projects that require further modularization of filtration, air supply and local air circulation, the BFU can be used as a clean room terminal air treatment device.

Modular air handling

Each BFU can be used as an independent air supply unit and configured according to the clean room layout.

local area control

According to the cleanliness requirements of different areas, the corresponding number and operation mode of air supply equipment can be configured.

Integrated with air conditioning system

Duct-connected BFU can be used with upstream air conditioning and air supply systems.

Self-circulating air supply

The self-circulating BFU can complete air circulation, filtration and air supply inside the clean space.

The specific system form needs to be comprehensively determined based on the clean room area, cleanliness level, ventilation needs, temperature and humidity control, and air conditioning system solutions.

What is the difference between BFU and FFU?

It should be noted that BFU and FFU are not completely unified in the product definitions of different manufacturers, so the actual selection should be based on the specific equipment structure and project system plan.

BFU filtration system - HEPA / ULPA filtration, configured according to cleanliness level

BFU filters need to be selected based on the clean room grade, target particle control requirements, air volume and system resistance.

HEPA filter

For common high-efficiency air filtration needs.

ULPA filter

Used in clean environments with higher requirements for finer particle control.

filter level

Specifically, you can choose the corresponding HEPA or ULPA grade according to project requirements.

filter size

Determine based on the BFU box size, air volume requirements and installation method.

Filter replacement

The filter is a maintenance component of the BFU and needs to be inspected and replaced according to the operating environment, pressure difference and clean room management requirements.

BFU from different manufacturers can be equipped with HEPA or ULPA filters. The actual filtration level and filter efficiency need to be based on the specific product model and test standards.

Fans and motors—select fans based on air volume and static pressure

BFU's fans are not a fixed configuration.

Different clean rooms have different air supply volumes, static pressures, filter resistances and installation methods, so the fans need to be matched according to the system working conditions.

EC motor

Suitable for applications requiring speed regulation and operation control.

DC motor

Can be configured based on the power and control requirements of the specific project.

AC motor

Suitable for projects with corresponding power supply conditions and operating modes.

Fan selection

The fan ultimately needs to be combined with:

Target air volume → system static pressure → filter resistance → power supply → control mode to determine.

Therefore, the BFU page does not recommend giving a fixed air volume and power parameter that applies to all products. The specific data should be based on the specific model.

Air flow organization-after filtration, how is the air flow sent out evenly?

BFU not only needs to complete air filtration, but also needs to consider the airflow organization downstream of the filter.

After the air passes through the filter, if it directly enters the clean space, the airflow distribution may be affected by the fan position, box structure, filter resistance and installation method.

Therefore, some BFU adopt:

Internal air duct → guide structure → diffusion plate/Punching Plate → air outlet surface to further distribute the filtered air.

The airflow organization methods used by different BFU products are not exactly the same, and the specific structure needs to be determined based on the product design and target air supply conditions. For example, different airflow diffusion structures such as Punching Plate and Air Blade.

BFU installation method - choose the installation method according to the clean room structure

Ceiling installation

BFU is commonly found in clean room ceiling systems as terminal clean air supply equipment.

Duct connection

The BFU can be connected to the upstream air conditioning duct according to the system design.

Self-looping

Some BFU can take air from inside the clean room and send it into the room again after being processed by fans and filters.

Non-standard installation

For the space above the equipment or special clean area, the structure can be designed according to the installation conditions.

BFU control system

From stand-alone operation to centralized control

Single machine control → wind speed adjustment → multiple group control → centralized control → remote monitoring

Depending on project requirements, BFU can be configured with different control schemes. For clean rooms that require unified management of multiple devices, group control and centralized control systems can be further considered.

The control method should be confirmed based on the motor type, on-site electrical system, and customer automation requirements.

Aili Industrial BFU box material - choose box material according to the environment

Aili industrial manufacturing capabilities - from fans, motors, filters to clean equipment

Aili Industry has established a product manufacturing system around clean air treatment equipment covering fans, motors, filters, sheet metal structures and control systems.

Fans and motors

Product matching is carried out according to the air volume, static pressure and control requirements of the clean equipment.

filter

Configure high-efficiency filtration solutions such as HEPA and ULPA.

Sheet metal manufacturing

Carry out box processing according to BFU size and internal structure.

control system

Configure speed regulation and control solutions according to motor and project control requirements.

Whole machine assembly

Complete machine assembly and product inspection of fans, filters, boxes and control components.

Through the collaboration of multiple links, it is easier to configure the combination of size, material, filter and control requirements in the BFU project.

BFU technical parameters

Note: The air volume, static pressure, power, noise and other parameters of BFU are related to product size, fan, motor, filter resistance and system working conditions. Therefore, the final parameters should be based on the specific model and technical plan.

BFU selection

How to choose the right BFU?

01 Cleanliness level → 02 Room area → 03 Installation space → 04 Target air volume → 05 System static pressure → 06 Filter level → 07 Fan and motor → 08 Control method → 09 Installation form → 10 BFU quantity

It is recommended to provide this information

Clean room area · Cleanliness level · Room height · Installation location · Target wind speed · Air volume requirement · Static pressure · Filtration level · Power supply · Control method · Number of BFU

If the project does not yet have complete air volume and static pressure data, you can also provide room size, cleanliness level, installation space and air conditioning system information before proceeding with subsequent selection.

Frequently Asked Questions about BFU Fan Filter Unit

What is BFU?

BFU is the abbreviation of Blower Filter Unit. It is a clean air supply equipment that combines blower/Fan, filter and air supply structure. It can be used for air filtration and air supply in clean rooms and local clean spaces.

What is the difference between BFU and FFU?

Both BFU and FFU are powered filter air supply equipment, but the product definitions and structures of different manufacturers are different. BFU usually emphasizes the combination of blower and filter, and can adopt air duct connection type or self-circulation structure; FFU is usually a modular air supply unit composed of a fan and a filter. Specific judgments need to be made based on the product structure and project system.

Can BFU use HEPA filters?

Can. HEPA is one of the common filter configurations of BFU. The specific filtration level needs to be selected based on the cleanliness level, target particle control requirements and system resistance.

Can BFU use ULPA filters?

Can. For clean environments that require a higher level of particulate matter control, ULPA filters can be selected based on project requirements.

Can BFU be connected to air conditioning ducts?

Can. Some BFUs adopt an air duct connection structure, and the air is provided by the upstream air conditioning system, which is then filtered by the BFU and sent to the clean space.

Can BFU self-circulate?

Can. Some products adopt a self-circulation structure, taking air from inside the clean room, and then sending it into the room again after being processed by fans and filters. The specific structure needs to be confirmed according to the project plan.

Is BFU suitable for installation on the ceiling of a clean room?

Can. Ceiling installation is one of the common application methods of BFU. The product size and installation method can be designed according to the clean room ceiling structure and installation space.

Can BFU use EC motors?

Can. Whether to use an EC motor needs to be determined based on air volume, static pressure, power supply and control requirements. For projects that require speed regulation or centralized control, the corresponding motor and control system can be selected according to the specific plan.

Can BFU customize the size?

Can. The size of the BFU needs to be determined based on the installation space, filter size, air volume and internal structure, so it can be customized according to project conditions.

Can BFU use stainless steel cabinets?

Can. According to the project requirements, stainless steel materials such as SUS304 and SUS316 can be selected, and other box materials can also be selected according to the environment and project standards.

How often do BFU filters need to be replaced?

There is no uniform fixed value for the filter replacement cycle, which will be affected by factors such as the clean room environment, air dust content, operating time, and changes in the initial resistance of the filter. During actual maintenance, it is recommended to make judgments based on the filter pressure difference, clean room management requirements and equipment operating status.

How does BFU determine air volume?

It needs to be comprehensively determined based on the clean room area, cleanliness level, ventilation requirements, target wind speed, filter resistance and system static pressure, rather than selecting a fixed air volume based only on the room area.

What is the price of BFU?

BFU price is related to product size, fan, motor, filter, box material, control method and purchase quantity. Only after the specific configuration is determined can an accurate quotation be made.

Can Aili Industrial customize BFU?

Can. Aili Industry can carry out BFU product configuration and structural design based on installation space, cleanliness level, air volume, static pressure, filters, motors, materials and control requirements.