What is the difference between the internal circulation and external circulation of car air conditioning?
4 Answers
The differences between the internal circulation and external circulation of car air conditioning are: 1. Different icons: The internal circulation icon is a closed car with a circulating arrow inside; the external circulation icon is an open car with an air arrow pointing into the car from outside. 2. Different working methods: Internal circulation allows the air inside the car to circulate in a closed environment; external circulation brings outside air into the car. 3. Different functions: The function of internal circulation is to heat or cool the air inside the car and then recirculate it; the function of external circulation is to heat or cool the outside air and then bring it into the car, enabling gas exchange between the inside and outside of the car.
As a seasoned driver with over a decade of experience, I've always paid attention to the difference between recirculation and fresh air modes, which relates to both comfort and safety. The recirculation mode continuously circulates the air inside the vehicle without drawing in outside air, making it ideal for avoiding exhaust fumes or dust in city traffic jams and allowing the AC to cool or heat quickly. However, keeping it on for extended periods can easily cause windows to fog up, especially on rainy days, which dangerously obstructs visibility. Switching to fresh air mode at this point draws in outside air, helping to dehumidify and ventilate. During highway driving, using fresh air mode is more fuel-efficient and maintains fresh air circulation—I often adjust it this way when traveling with family. The auto AC's smart mode can switch automatically, which is quite convenient, but I recommend manual control to ensure optimal conditions.
For car modification enthusiasts, I've studied how the air conditioning system works. Pressing the recirculation button means the fan only blows interior air without drawing in external air; the fresh air mode does the opposite, bringing in outside air. The key lies in air filtration – during recirculation, the filter needs frequent cleaning, otherwise dust buildup affects health and makes the air stuffy. Switch to recirculation during heavy smog for protection, but immediately activate fresh air mode if there's odor inside. Vehicle ventilation design makes a big difference – for instance, during rain or fog, just a few minutes in fresh air mode solves the problem with simple, efficient operation.
As a new driver who just got my license, I'm exploring the AC buttons. The recirculation mode keeps air circulating inside the car without letting outside air in; while fresh air mode draws in outside air. Use recirculation in city driving to block exhaust fumes, but switch to fresh air when windows fog up after prolonged use. On highways, fresh air mode works better - it's more fuel-efficient and comfortable. Winter or rainy/foggy days may lead to misoperation, but it becomes second nature with practice.
