Is it okay to sleep in the car without turning on the air conditioning?
3 Answers
It is okay to sleep in the car without turning on the air conditioning. In fact, it is better not to turn on the air conditioning, especially when the doors and windows are closed. Here are the reasons why you can sleep in the car without turning on the air conditioning: Car "Internal Circulation": Internal circulation means the air circulates within the car without any external air entering. In this mode, outside exhaust fumes and dust do not enter the car, and the air conditioning's cooling and heating effects are more efficient. Internal circulation is suitable for use in traffic jams or polluted areas. However, if you sleep in the car with the air conditioning on and internal circulation activated, the small space and lack of air exchange with the outside can lead to oxygen depletion inside the car over time, potentially causing suffocation due to lack of oxygen. Car "External Circulation": External circulation allows a small amount of outside air to enter the car while the air is circulating, providing fresh air to the interior. However, this reduces the efficiency of the air conditioning's cooling and heating. External circulation is suitable for situations with many passengers or long drives. If you sleep with external circulation on and the car is in a confined, poorly ventilated space, such as a garage or near a wall, exhaust fumes can accumulate around the car and enter through the air conditioning intake, leading to carbon monoxide poisoning.
I think sleeping in the car without turning on the AC is quite dangerous, especially if you leave the engine running. Harmful gases like carbon monoxide can accumulate inside the car, and inhaling them for just a few minutes can lead to poisoning. Once, during a family road trip, I tried to save fuel by not using the AC while resting by the roadside at night. Luckily, a passing driver reminded me to open the windows. Since then, I always advise against sleeping in the car. If you must do it, make sure to crack the windows for ventilation—never seal them shut. Temperature control is another issue. In summer, it's too hot to sleep, and in winter, you'll shiver from the cold. It's safer to find a motel or set up a tent instead. Safety should always come first.
From my experience of trying to sleep in a car overnight, it's really uncomfortable to sleep in a car without turning on the air conditioning. For example, during a long trip when I was too tired and wanted to take a nap, even with the window slightly open without the AC, I still woke up in the middle of the night sweating all over and feeling completely exhausted. I think this has an impact on health, as poor sleep quality leads to lack of energy for driving the next day. Moreover, doing this long-term may cause respiratory issues or colds. I suggest bringing a thin blanket to regulate body temperature, or simply avoid sleeping in the car too often. Comfort is important, so try not to stay in excessively hot or cold environments for too long.
