Should You Use Internal or External Air Circulation for Car AC in Summer?

[ConnorLee]

In summer, car air conditioning generally uses internal circulation, switching to external circulation for air exchange. Choose an appropriate temperature based on the level of heat, typically between 22 to 24 degrees Celsius in summer for relative comfort. Regarding the use of internal and external circulation, it is recommended to use external circulation when you need to quickly lower the cabin temperature or exchange air inside the vehicle; otherwise, internal circulation is sufficient. Here are some considerations: Expel hot air in advance: Before using the AC in summer, ventilate the cabin to let the hot air escape. The main method is to open the same-side door or lower the window fully while keeping the opposite-side window closed, then swing the door to facilitate hot air flow; alternatively, open all four windows or diagonally opposite windows while driving to accelerate hot air circulation. Once the interior and exterior temperatures are similar, close the windows, turn on the AC cooling function, and set the air circulation to external. The temperature can be adjusted to the lowest setting to speed up cabin temperature stabilization.