What factors should be considered when choosing an FFU?

When choosing an FFU (Fan Filter Unit), the following multiple factors need to be considered:
Cleanliness requirements: Select based on the cleanliness level standards of the usage environment. For example, in semiconductor manufacturing workshops, it is usually necessary to achieve ISO level 1 or higher in terms of cleanliness. This requires FFUs to have highly efficient filtration capabilities and be able to filter out particles of extremely small sizes. Generally, high-efficiency air filters (HEPA) or ultra-high-efficiency air filters (ULPA) need to be configured. For some ordinary cleanrooms, such as the general production areas in pharmaceutical factories, achieving ISO level 7 or 8 cleanliness is sufficient, and FFUs with corresponding filtration efficiency can be selected.
Air volume requirement: Determine the required air volume based on the room size, air change rate, etc. For instance, for a clean room with an area of 100 square meters and a height of 3 meters, if it is required to change air 20 times per hour, the total air volume needed would be 100×3×20 = 6,000 cubic meters per hour. Then, based on the number of FFUs arranged in the clean room, calculate the air volume required for each FFU. Generally speaking, the air volume range of FFU is between 800 and 2,340 cubic meters per hour. You can choose a product with an appropriate air volume according to your actual needs.
Filtration efficiency: Different application scenarios have different requirements for filtration efficiency. For instance, in medical operating rooms, it is necessary to filter out bacteria, viruses, and other microorganisms in the air. The filtration efficiency of the FFU should reach over 99.97% (for particles with a diameter of 0.3 microns), that is, HEPA filters should be adopted. In some electronics factories with high requirements for dust, ULPA filters with higher filtration efficiency may be needed, which can achieve a filtration efficiency of over 99.999% for particles with a diameter of 0.12 microns.
Fan performance: including the type, power, rotational speed, noise, etc. of the fan. Common types of fans include centrifugal fans and axial fans. Centrifugal fans have high air pressure and stable air volume, making them suitable for clean rooms that need to overcome significant resistance. Axial flow fans have a large air volume and low energy consumption, but their air pressure is relatively small. They are suitable for places where the requirements for air pressure are not high. The power and rotational speed of the fan determine the air volume and pressure. Appropriate parameters should be selected based on actual needs. At the same time, attention should be paid to the noise level during the operation of the fan. In some environments with strict noise requirements, such as laboratories and hospital wards, FFUs with low noise should be selected, generally not exceeding 60 decibels.
External dimensions and installation method: Select the appropriate external dimensions and installation method of FFU based on the on-site spatial layout and installation conditions. The common external dimensions of FFUs include 610×610 millimeters, 600×1200 millimeters, 1200×1200 millimeters, etc. The installation methods include hoisting, pedestal installation, embedded installation, etc. For example, in places where the ceiling space is limited, a floor-mounted FFU can be chosen; In some cleanrooms that require an overall aesthetic appearance, embedded FFUs can be adopted.
Energy consumption and operating costs: Consider the power of the FFU, the energy efficiency ratio, and the electricity cost for long-term operation. For instance, DC FFUs have a higher energy efficiency ratio compared to AC FFUs. Although the initial investment may be larger, it can save a considerable amount of electricity in the long run. Take a cleanroom with 100 FFUs as an example. If each DC FFU saves 1 kilowatt-hour of electricity per day compared to an AC FFU, and calculated based on 300 days in a year, 30,000 kilowatt-hours of electricity can be saved. The electricity cost is considerable.