What are FFU module dimensions?

FFU is a modular device designed with standard module dimensions to facilitate uniform installation and flexible combination on the clean room ceiling keel. Module size is derived from imperial units, 1 module is approximately 2 feet (610mm), and is usually rounded to an integer after metric conversion to form a standard size series common in the industry.

The overall dimensions of the FFU need to match the keel grid of the clean room ceiling. Common keel grids are 600×600mm, 1200×600mm, 1200×900mm, 1200×1200mm, etc. The size of FFU usually corresponds to these grid sizes to achieve seamless installation.

FFU standard size specifications

The mainstream dimensions of FFU currently on the market include the following:

(1) Imperial dimensions (converted to metric)

(2) Commonly used metric dimensions

In addition, some customers will also use specifications such as 610×610mm, 610×1220mm, etc. that are close to the original imperial size according to their own clean room keel spacing requirements.

Application scenarios of FFU of different sizes

575×575mm (2×2 feet)

Suitable for small-area clean areas, clean workbench facilities, laboratories and scientific research institutions. The air volume of a single unit is usually 500-800m³/h, which is suitable for independent use or combination in small quantities. Light weight, easy for one person to install and carry.

1175×575mm (4×2 feet)

The mainstream size in the market and the most widely used. The air volume of a single unit is usually 1000-1600m³/h, which is suitable for most clean room scenarios such as semiconductors, panel displays, pharmaceuticals, electronics, and food. Seamless installation is possible in the 1200×600mm keel grid.

1175×1175mm (4×4 feet)

It is suitable for large-area high-cleanliness clean rooms. The air volume of a single unit is usually 2000-2500m³/h. Compared with small-size FFU, fewer installations are required for the same area, which can reduce the number of equipment and joints. However, the weight of a single unit is heavier and the load-bearing requirements for the ceiling are higher.

How to choose FFU size in different scenarios?

The relationship between FFU size, cleanliness and air volume

Under the same face wind speed, the larger the size of the FFU, the larger the air outlet area, and the larger the air volume of a single FFU. Conventional clean room design usually requires the wind speed on the FFU outlet surface to be between 0.35-0.55m/s, and the air volume calculation formula is:

Air volume (m³/h) = Air outlet area (m²) × Surface wind speed (m/s) × 3600

Taking 1175×575mm FFU (air outlet area about 0.65m²) as an example, at a surface wind speed of 0.45m/s, the air volume of a single unit is about 0.65×0.45×3600=1053m³/h.

When selecting the FFU size, it is necessary to comprehensively consider the clean room area, target cleanliness level, FFU coverage rate and ceiling keel layout to strike a balance between the number of equipment, installation cost and energy consumption.

Non-standard customized FFU size

In addition to the above standard specifications, many projects require FFU of non-standard sizes due to equipment layout, ceiling structure or process requirements. Aili Industrial supports customizing non-standard size FFU according to customer needs. It can flexibly design and manufacture according to the actual keel spacing, equipment top space and air volume requirements of the clean room, ensuring that the FFU perfectly matches the on-site installation conditions.

Customizable content includes:

• Appearance length and width (any non-standard size)

• Cabinet thickness (standard or ultra-thin)

• Box material (galvanized plate, stainless steel, aluminum alloy, etc.)

• Air outlet structure (diffusion plate type, opening ratio, etc.)

Common misunderstandings in FFU size selection

Myth 1: Bigger is better. FFU size is not always better. Large-size FFUs weigh more and have higher load-bearing requirements on the ceiling, making installation and maintenance more difficult. Reasonable selection should be based on actual air volume requirements and keel layout.

Misunderstanding 2: Ignoring keel matching. When selecting FFU, you must ensure that the size matches the clean room ceiling keel grid, otherwise tight installation cannot be achieved, which may result in air leakage or substandard cleanliness.

Misunderstanding 3: Ignoring weight. The weight of a single large-size FFU increases significantly, and the ceiling load-bearing capacity needs to be confirmed before installation.

Summarize

The size selection of FFU is directly related to the rational layout, installation convenience and long-term operation stability of the clean room. Common standard specifications such as 575×575mm, 1175×575mm, and 1175×1175mm each have their own applicable scenarios. When selecting, the clean room area, target cleanliness level, ceiling keel layout, and single unit air volume requirements should be comprehensively considered.

For unconventional installation conditions, it is particularly important to choose an FFU manufacturer with non-standard customization capabilities to ensure that the equipment perfectly matches the site conditions.

Aili Industry—Full industry chain FFU manufacturer

Aili Industrial has been deeply involved in the field of clean room equipment for nearly two decades. From fan winding, box processing to control system development, the entire industry chain independently manufactures FFU fan filter units. The products cover standard sizes such as 575×575mm, 1175×575mm, 1175×1175mm and various non-standard customized sizes. They support full-dimensional customization of size, material, motor, control method, filtration level, etc., and adapt to the different cleaning needs of 13 major industries such as semiconductors, panel displays, pharmaceuticals, food, and data centers.

If you need FFU selection suggestions or customized solutions, please contact the professional technical team of Aili Industry.