Ventilation system and ventilation methods

PROBLEM TO BE SOLVED: To provide a ventilation system capable of preventing contaminated air from diffusing to a place where people exist, and maintaining comfort.SOLUTION: A controller 80 of a ventilation system 100 locates the position of a person from a detection result of a human position detection sensor 11, and locates the position of a contamination source from a detection result of a contamination degree detection sensor 12. Then, in order to form air flow from the position of the person toward the position of the contamination source, air amounts of a plurality of air supply fans 210, 220, 410, and air amounts of a plurality of exhaust fans 230, 240, 310, 510, 610 are controlled.SELECTED DRAWING: Figure 4