How to Calculate the Number of FFU Fan Filter Units
In the design and construction of cleanrooms, FFU (Fan Filter Unit) is a commonly used air purification device. Accurately calculating the number of FFUs is critical to ensuring optimal air quality and purification performance in the cleanroom. Below are the key parameters and calculation methods to help you determine the correct number of FFUs needed.
Key Parameters
- Cleanroom Area: This is the foundation of the calculation. It requires precise measurements of the length, width, and height of the cleanroom.
- Cleanroom Classification: Based on the concentration of airborne particles, different cleanroom classes have varying requirements for air cleanliness.
- FFU Air Volume: The volume of air processed by an FFU per unit time, usually measured in cubic meters per hour (m³/h).
- FFU Efficiency: The filtration efficiency of the FFU for airborne particles, typically expressed as a percentage.
Calculation Methods
Air Changes Per Hour (ACH) Method
Based on the cleanroom class and its area, calculate the required total air volume to be replaced every hour. Then divide this number by the airflow rate of a single FFU to get the total quantity needed. The formula is as follows:
Number of FFUs = Cleanroom Area × Air Changes per Hour ÷ FFU Air Volume
Average Air Velocity Method
Calculate the average air velocity required within the cleanroom based on its classification and area. Then use the FFU’s airflow rate and efficiency to determine the number of units required. The formula is:
Number of FFUs = Cleanroom Area × Average Air Velocity × 3600 ÷ (FFU Air Volume × FFU Efficiency)
Important Considerations
- The calculated result should be adjusted according to actual conditions, such as cleanroom layout, number of personnel, and quantity of equipment.
- Select appropriate FFU models and specifications to ensure they meet the air quality standards of the cleanroom.
- Follow the installation and commissioning instructions provided by the FFU air filter manufacturer to guarantee proper operation.
- Perform regular maintenance and servicing of the FFUs to extend their service life and maintain consistent purification performance.
By using the above methods, you can accurately determine the required number of FFUs to ensure that the cleanroom meets air quality standards, thereby improving production efficiency and product quality.
About E-FILT
E-FILT is a professional air filter manufacturer dedicated to delivering high-performance air filtration solutions for cleanrooms, laboratories, industrial facilities, and HVAC systems. With a focus on innovation, quality, and reliability, E-FILT provides a comprehensive range of products, including HEPA filters, ULPA filters, and FFU units. Our engineering team ensures that every solution is tailored to meet specific project requirements, helping clients achieve cleaner environments and more efficient operations. Whether you’re building a new cleanroom or upgrading an existing system, E-FILT is your trusted partner for advanced air filtration technology.
