Cleanroom HVAC systems, especially those requiring fan filter units (FFU) for recirculating air, typically account for a large portion of energy use in cleanrooms.

Performance of HVAC systems varies significantly from cleanroom to cleanroom largely because of various factors, such as contamination control requirements, air handling unit designs, air system resistance, and efficiency levels offered by system components. Studies have uncovered energy-saving opportunities in many cleanroom applications, and that optimizing aerodynamic performance in air recirculation systems appears to be a useful approach to improve energy efficiency in cleanrooms.

Because of their ease of installation, adaptability, and specific contamination control schemes, FFUs are being used more and more in air recirculation systems in cleanrooms. The large number of small fans can consume considerable energy in providing air recirculation. Therefore, understanding the performance of FFUs is important and can help to promote best practices in cleanroom design and operation. To date, typical manufacturer’s data sheets usually contain claims that are seemingly similar; however, they usually do not reveal test methods, if they exist at all. Furthermore, statements of performance data that include power, airflow, and sound are commonly vague and could be misleading.

In recent years, industries have shown growing interest in having a uniform method for testing and reporting FFU performance. Lawrence Berkeley National Laboratory (LBNL) is performing research to improve energy efficiency in contamination control facilities such as cleanrooms. The project goal is to develop a standard testing method for evaluating the performance of an FFU.

From: “Introducing a Standard Testing Method for FFUs”