Brothers, 20 models of Maiteng 330. After collecting the car for a few days, I felt hot wind blowing on my face when I was in the driver's seat. At first, I didn't care. I thought the air conditioner was on. Later, I found that the air conditioner could not be turned on, but there was also obviously hot air. When I went to the 4S store, the maintenance worker said that it was because the external circulation was turned on, which brought the heat of the engine into the car. If it was internal circulation, there would be no hot air. Practice has proved that there is no hot air when opening internal circulation. But is this a normal phenomenon? In addition, it is said that the new car should use the external cycle. Is there any problem with driving the internal cycle for such a long time? Ask friends to answer!