Effects of the Removal of 0.1 μm Particles in Industrial Cleanrooms with a Fan Dry Coil Unit (FDCU) Return System

A wall-return ventilation system, containing ceiling-supply and wall-return air grilles, is traditionally used in non-unidirectional airflow cleanrooms. In such a wall-return cleanroom, the pathways of return airflow towards the wall-return grilles may be affected by locations and layouts of the production lines and tool equipment; moreover, especially considering the needs for relocation of production lines and rearrangement of tool equipment in the industrial cleanrooms, this study proposed a fan dry coil unit (FDCU) return system, containing ceiling-supply and ceiling-return air grilles, and conducted experimental works in a full-scale cleanroom to investigate the performance of the innovative and traditional ventilation systems. The influences of air change rates and supply air plenum pressures on the removal of 0.1 mu m particles were examined in the experiment. Results presented in this paper were subject to the particle size of 0.1 mu m. The FDCU-return ventilation arrangement may provide viable solutions to effective contamination control. The results showed that the innovative FDCU-return system can effectively eliminate about 50% of 0.1 mu m particles from the cleanrooms more than the conventional wall-return system. Moreover, the outcomes from this study suggested that particle removal rates for the given cleanrooms were significantly affected by air change rates.