Should You Use Internal or External Air Circulation When Running the Car AC on Hot Days?
1 Answers
On hot days, for regular cooling, first turn on the internal circulation before switching to external circulation. If the car has been exposed to direct sunlight, open the windows first before turning on the external circulation. Here is some relevant information about internal and external air circulation in cars: 1. The Principle of Internal and External Circulation: External circulation essentially draws air from outside the vehicle, filters it through the AC filter, and delivers it into the cabin via the blower. Internal circulation, on the other hand, simply blocks the external air intake. Whether using internal or external circulation, exhaust air inside the car is expelled through the vents, so there's no need to worry about oxygen levels even when using internal circulation. 2. When to Use External Circulation: Whether heating or cooling, windows are usually closed initially to quickly reach the desired cabin temperature. Over time, without fresh air, the cabin air becomes stale and oxygen levels drop. At this point, switching to external circulation allows fresh outside air to enter, facilitating quick air exchange. 3. When to Use Internal Circulation: Internal circulation is typically used when first turning on the heater or AC. Additionally, when outside air quality is poor, it's advisable to switch from external to internal circulation to prevent harmful gases from entering the cabin. Don’t assume that internal circulation makes the cabin airtight—even with internal circulation on, exhaust air is still expelled through the vents, though outside air is blocked.
