Does the car air conditioner cool in external circulation or internal circulation?

[McMason]

Car air conditioner cools in external circulation. The air conditioner has two circulation states: internal circulation and external circulation. The following is relevant information about internal and external circulation: 1. Meaning of internal and external circulation: Internal circulation means the air inside the vehicle is circulating, i.e., the air from the vents comes from inside the cabin, which is sealed and not connected to the outside atmosphere. External circulation means outside air enters the cabin, and the air from the vents comes from outside the cabin, which is connected to the atmosphere and not sealed. 2. Technical characteristics of internal and external circulation: Internal circulation means the air blown by the blower circulates only inside the vehicle. Since no external air is involved, it has the advantages of fuel efficiency and faster cooling (or heating), but the disadvantage is poor air renewal inside the vehicle. External circulation means the blower draws fresh air from outside into the vehicle, which ensures better air quality inside the cabin, but cooling (or heating) is slightly slower and consumes more fuel.