This a smart ventilator fan system. When it detects the presence of a user, it spins in one direction and blows the air towards the user, very much like an electric fan. However, it starts at a particular lower speed and increase to the top speed only if the user remains detected after a fixed delay. Otherwise, the ventilator sucks air out from the room when no user is detected. During maintenance, the technician can toggle off this automatic mode with a Push Button and use the Potentiometer to check that the fan works in both speeds and in both directions.-This is a smart ventilator fan system. When it detects the presence of a user, it spins in one direction and blows the air towards the user, very much like an electric fan. However, it starts at a particular lower speed and increase to the top speed only if the user remains detected after a fixed delay. Otherwise, the ventilator sucks air out from the room when no user is detected. During maintenance, the technician can toggle off this automatic mode with a Push Button and use the Potentiometer to check that the fan works in both speeds and in both directions.