*Results are based on emission of the bacterium Pseudomonas Fragi (a simulant for a relevant pathogen) directly from clean units and clean filters, after 1,6 and 24 hours of continuous use, varying in water consumption from 30 to 120 ml/hr, using sterilized water spiked with said bacterium. Measurements were conducted using a 1 m3 (35 cuft) chamber refreshed at 560 L/min (148 gpm). Bacteria introduction into the air in the room depends on many factors such as room size or configuration.