Is It Safe to Sleep in a Car with the Air Conditioner and Windows Open?

[DeReese]

Sleeping in a car with the air conditioner and windows open is a safe practice. When the car is stationary with the air conditioner running, the engine operates in an idle state, leading to incomplete fuel combustion, which generates carbon monoxide. This carbon monoxide can enter the car's interior through the air conditioning system. However, if there is air exchange with the outside, it will not pose a harm to the human body. The car's "internal circulation" and "external circulation" modes: Internal circulation means the air circulates within the car without any outside air entering. In this mode, external exhaust fumes and dust do not enter the car, and the air conditioning's cooling or heating efficiency is better. Internal circulation is suitable for use in traffic jams or polluted areas. External circulation, on the other hand, allows a small amount of outside air to enter while the air inside the car circulates. This helps replenish fresh air inside the car but may reduce the efficiency of the air conditioning's cooling or heating. External circulation is suitable when there are many passengers in the car or during long drives. Safe methods for sleeping in a car: Do not close the windows tightly; maintain good air circulation inside the car. Open the windows slightly while sleeping to prevent the risk of suffocation. Park the car in an outdoor area with ample space before sleeping, as small spaces may have poor air circulation, making it difficult to ensure fresh air inside the car. Check for any exhaust leaks, as car exhaust entering the interior can easily lead to poisoning.