Switch cabinet arrangement having at least one switch cabinet housing and at least one cooling unit for cooling air accommodated in the switch cabinet arrangement, the cooling unit having at least one refrigerant circuit which has a flammable refrigerant, the switch cabinet arrangement having two refrigerant sensors which detect a concentration of the flammable refrigerant in the air and are evaluated by a control unit which is set up to trigger a safety function for lowering the concentration of the flammable refrigerant in the air below the limit value if a limit value of the concentration is exceeded, the safety function having a locking mechanism of the cooling unit, by means of which an air inlet of the cooling unit which is open to the interior of the switch cabinet and an air outlet of the cooling unit which is open to the interior of the switch cabinet can be closed, wherein the safety function further comprises a ventilation mechanism with at least one closing member (12, 16) adjustable between an air inner circuit and an air outer circuit of the cooling unit between an open position and a closed position, wherein in the closed position of the closing member (12, 16) the air outer circuit and the air inner circuit are fluidically separated from each other and wherein, in the open position of the closing member (12,16), ambient air is discharged from the air outer circuit into the air inner circuit and from the air inner circuit into the air outer circuit and from there into the environment of the switch cabinet arrangement, the safety function comprising a venting and exhausting mechanism, via which the switch cabinet arrangement is ventilated with ambient air and the air taken up in the switch cabinet arrangement is discharged into the environment of the switch cabinet arrangement, wherein an air refrigerant heat exchanger of the refrigerant circuit is arranged in the air inner circuit which has a first of the two refrigerant sensors on its inflow side and a second of the two refrigerant sensors on its outflow side, and wherein, in the event of a leakage detected with the aid of the refrigerant sensors, the control unit, which is likewise arranged in the interior of the cooling unit, can activate the locking mechanism, close off all the air passage openings (6, 7) between the inner circuit of the cooling unit and the inside of the cabinet housing, while opening the closing member (12,16) of the ventilation mechanism, so as to establish an air short-circuit between the inner circuit and the outer circuit of the cooling unit. safety function having a locking mechanism of the cooling unit, by means of which an air inlet of the cooling unit which is open to the interior of the switch cabinet and an air outlet of the cooling unit which is open to the interior of the switch cabinet can be closed, wherein the safety function further comprises a ventilation mechanism with at least one closing member (12, 16) adjustable between an air inner circuit and an air outer circuit of the cooling unit between an open position and a closed position, wherein in the closed position of the closing member (12, 16) the air outer circuit and the air inner circuit are fluidically separated from each other and wherein, in the open position of the closing member (12,16), ambient air is discharged from the air outer circuit into the air inner circuit and from the air inner circuit into the air outer circuit and from there into the environment of the switch cabinet arrangement, the safety function comprising a venting and exhausting mechanism, via which the switch cabinet arrangement is ventilated with ambient air and the air taken up in the switch cabinet arrangement is discharged into the environment of the switch cabinet arrangement, wherein an air refrigerant heat exchanger of the refrigerant circuit is arranged in the air inner circuit which has a first of the two refrigerant sensors on its inflow side and a second of the two refrigerant sensors on its outflow side, and wherein, in the event of a leakage detected with the aid of the refrigerant sensors, the control unit, which is likewise arranged in the interior of the cooling unit, can activate the locking mechanism, close off all the air passage openings (6, 7) between the inner circuit of the cooling unit and the inside of the cabinet housing, while opening the closing member (12,16) of the ventilation mechanism, so as to establish an air short-circuit between the inner circuit and the outer circuit of the cooling unit.