FFU Selection Guide: Comparison of Application Advantages of Single and Dual Fans

In modern cleanroom construction, Fan Filter Units (FFUs) are core air purification equipment. Depending on the number of fans, FFUs can be categorized as single-fan or dual-fan. Choosing the right FFU type is crucial for maintaining air cleanliness, reducing energy consumption, and extending equipment life. This article provides a detailed comparison of the two types based on performance, installation space, air volume, and application scenarios to help users make informed choices.

Single-Fan FFU

A single-fan FFU is the most commonly used fan-filter unit (FFU) in cleanrooms. It features a simple structure consisting of a housing, fan, aluminum impeller, and a high-efficiency HEPA filter. It can be configured with an H13, H14, or U15 terminal HEPA filter.

Advantages of Single-Fan FFUs

• Easy Installation: Single-fan FFUs are compact, fit into standard ceiling spaces, and are easy to install and maintain.

• Lower Cost: Compared to dual-fan FFUs, single-fan FFUs have lower initial investment and energy consumption, making them suitable for small to medium-sized cleanrooms.

• Suitable for low to medium air volume requirements: For cleanrooms with smaller areas or low air volume requirements, single-fan FFUs can meet air circulation and filtration requirements.

Suitable Applications

• Small to medium-sized pharmaceutical or electronics laboratories

• ISO Class 6–7 cleanrooms

• Production or research environments with less stringent air uniformity requirements

Dual-Blower FFU

A dual-blower FFU adds a second fan to a single-blower unit, achieving higher air volume and static pressure within the same space, ensuring stable air flow. Its core components also support H13, H14, and U15 HEPA filters, effectively filtering particles and microorganisms 0.1–0.3μm in size.

Advantages of a Dual-Blower FFU

• High Air Volume Output: Achieves higher air flow than a single-blower unit in limited space.

• Overcomes High-Resistance Filters: Suitable for environments equipped with H14 and U15 ultra-high-efficiency filters, ensuring stable air volume.

• Strong Stability and Reliability: The dual-blower units provide redundancy, ensuring that even if one fan fails, the other can still maintain partial air flow.

• Strong Intelligent Expansion: Optional differential pressure sensors, temperature and humidity sensors, and particle counters enable remote monitoring and automated management.

Applicable Scenarios

• Large cleanrooms (ISO Class 5 and above)

• High-standard environments such as pharmaceuticals, biological laboratories, and semiconductor manufacturing

• Applications requiring high airflow or high-resistance filters despite limited space

• Long-term continuous operation with high demands on equipment reliability

How to Choose the Right FFU Type

When selecting an FFU, consider the following factors:

• Cleanroom Area and Air Volume Requirements: For small cleanrooms with low air volume requirements, a single fan can be selected; for large cleanrooms with high air volume requirements, a dual-fan FFU is recommended.

• Filter Grade and Resistance: High-grade HEPA or U15 ultra-high efficiency filters are recommended with dual fans to ensure stable air volume.

• Space Constraints: If ceiling height or installation space is limited but high air volume is still required, a dual-fan FFU can be selected to achieve high efficiency output from a single unit.

• Uptime and Reliability: For environments with long-term continuous operation or high system reliability requirements, a dual-fan FFU is more suitable.