Which is cooler, the car air conditioner's external circulation or internal circulation?
2 Answers
Using the car air conditioner's internal circulation is cooler. Here is the relevant information: 1. Internal and external circulation: Generally, when turning on the air conditioner, you can first activate the internal circulation to quickly lower or raise the temperature inside the car. Once the temperature stabilizes, you can appropriately switch to external circulation to exchange air with the outside. 2. Location: The air intake for the internal circulation is inside the car, meaning outside air cannot enter, and inside air cannot exit. The air intake for the external circulation is located below the front windshield wiper, at the junction of the windshield and the engine hood. This draws in outside air. A more noticeable difference lies in the air freshness. Over time, the air in internal circulation becomes stale, oxygen levels drop, which can make people feel hot, fatigued, anxious, and affect driving safety.
As a seasoned driver with years of experience, I believe using the car's air conditioning in recirculation mode cools down the cabin much faster. It only processes the air inside the vehicle. For instance, when you first get in the car on a hot summer day with scorching wind blowing outside, switching to recirculation mode can bring the temperature down within minutes—this effect is especially noticeable during highway traffic jams. I've also found it helps save fuel since the compressor works less. However, don't keep it on continuously for too long, as the air can become stuffy over time, sometimes even making your mouth feel dry. That's why I switch to fresh air mode every half hour to circulate some outside air. This way, you stay cool without discomfort. Remember to regularly check and clean the air filter too. Overall, using recirculation mode provides significantly better cooling than fresh air mode.
