Should I Use Recirculation or Fresh Air Mode for Defrosting Windows?
3 Answers
Fresh air mode should be used for defrosting windows. Below is relevant information about fresh air mode: 1. Fresh air mode button: The air conditioning control panel has both recirculation and fresh air mode buttons. The recirculation button icon shows a car with an arrow circulating inside the vehicle. The fresh air mode button icon shows a car with an arrow entering from outside the vehicle. Drivers can locate these buttons on the air conditioning control panel. All car air conditioning systems have both recirculation and fresh air functions. When fresh air mode is activated, outside air will enter the vehicle. 2. When to use fresh air mode: Fresh air mode is suitable when it's inconvenient to open windows for ventilation, such as when driving on highways. However, when passing through areas with heavy dust or traffic congestion, recirculation mode should be used. If fresh air mode is activated in heavy traffic areas, exhaust fumes may enter the vehicle.
When dealing with frost on the windshield, I've found that using the external air circulation is the best choice. The internal circulation recirculates the humid air inside the car, trapping moisture like exhaled vapor, which only makes the fog worse. The external circulation draws in fresh, dry air from outside and, when combined with the heater, directs it toward the windshield, quickly evaporating the frost and fog. I often encounter fogging on winter mornings, so I turn on the air conditioning, switch to external circulation mode, increase the fan speed, set a higher temperature, and aim it at the windshield. Within minutes, it clears up. Avoid the temptation to use internal circulation, as it will cause the fog to keep coming back, compromising driving safety. As a side note, regularly cleaning the interior glass to remove oily residues can help prevent frost buildup and maintain clear visibility.
As a car user, I recommend selecting the external air circulation mode for defogging. The principle is simple: internal circulation seals the cabin, increasing humidity which causes fog to condense on the windows; external circulation introduces dry outside air, diluting moisture and accelerating defogging. In practical operation, press the defog button on the AC, switch to external circulation mode, and appropriately heat the air. From experience, I know fogging occurs most frequently on rainy or cold days, and adding warm air works even better. Meanwhile, check if the fan is functioning properly - higher fan speed can enhance the effect. Prolonged use of internal circulation also tends to accumulate odors, which are harmful to breathing, so developing the habit of using external circulation is both healthier and more effective.
