AIR CONDITIONING AND VENTILATION SYSTEM

An air conditioning and ventilation system S comprising: an air conditioner A that has a heat exchanger 22 for generating conditioned air by exchanging heat with a refrigerant, and sends the conditioned air to a space R to be air-conditioned; a ventilator 30 that ventilates the space R to be air-conditioned; a refrigerant sensor 24 for detecting the concentration of the refrigerant in the space R to be air-conditioned; and a control unit 40 that controls the operation of the air conditioner A and the ventilator 30. Upon determining that the refrigerant concentration obtained from the refrigerant sensor 24 exceeds a first predetermined value, the control unit 40 stops the operation of the compressor 13 of the air conditioner A and operates the ventilator 30. Upon determining that the refrigerant concentration, which had exceeded the first predetermined value, has become less than or equal to the first predetermined value, the control unit 40 continues to stop the compressor 13 of the air conditioner A and operate the ventilator 30 until a predetermined timing.