Fan-filter unit systems are used for re-circulating clean air in cleanrooms are gaining popularity in California as well as in the rest of the world. Under normal operation, fan-filter units require high power demand, typically ranging from 100 to 300 W per square meter of cleanroom floor area (or approximately 10-30 W/ft2). Operating 7 by 24, they normally consume significant electric energy, while providing required contamination control for cleanrooms in various industries. Previous studies focused on development of a standard test procedure for fan-filter units. This project is to improve the methods, and develop new information to demonstrate the methods can be used to assist the industries to apply more energy-efficient fan-filter units in cleanrooms.

Specifically this project expands previous developmental activities of a test protocol to characterize a pool of 17-sample fan-filter units (FFUs) recruited from Asia, Europe, and North America. Through laboratory experiments and modeling, the project develop and demonstrate means of identifying and applying existing or new filtration techniques with higher energy efficiency in the market. All the FFUs had a nominal size of 61-cm-by-122-cm (2-ft by 4-ft). We established a new testing facility, performed new laboratory test using a refined test method, conducted data analyses, developed models to characterize energy performance of the 17 FFUs. Based upon the laboratory test results, we developed a relative ranking system to compare energy efficiency of the FFUs, and recommended options of formulating initial energy-incentive criteria for consideration and use in utility companies' future rebate programs.