How the exhaust fan works will depend on the type of activation system it has. Manual types are activated at the press of a button. Meanwhile, those connected to the light switch are activated by turning on the bathroom light. There are also models with more advanced technology. They are activated by detecting the presence of a person through infrared systems. The hygrostats with sensors are activated according to the humidity of the environment. The ones with timers can renew the atmosphere from time to time. If you have an axial type exhaust fan connected to the light switch, entering the bathroom will turn it on automatically. The fan, thus, begins the process of ventilation and removal of air. This eliminates bad odors and reduces humidity in this space.