Why Can Turning on the Air Conditioning in a Car Be Fatal?
3 Answers
When the engine is running, if the gasoline in the cylinders does not burn completely, it produces high concentrations of carbon monoxide. While the car is moving, the air passing through the air conditioning system creates convection, keeping the carbon monoxide concentration inside the car low. However, when the car is stationary with the air conditioning still on and the windows and doors closed, the carbon monoxide emitted by the engine gradually accumulates, increasing its concentration, which can lead to poisoning or even death. Here are precautions for sleeping in a car with the air conditioning on: 1. Park in an open area: The car should be parked in an open space, preferably with the front facing the wind direction, so that even if the engine is not turned off, the exhaust will be blown away. If parked in a confined space like an underground parking lot, exhaust fumes can seep into the car. 2. Leave a window gap: When sleeping with the air conditioning on, leave a 2-3 cm gap in the window to prevent suffocation or carbon monoxide poisoning. However, the gap should not be too large to prevent potential criminal activity. 3. Use the air conditioning's external circulation mode: It is best to turn on the external circulation mode when sleeping in the car, as this mode draws outside air into the car, maintaining air circulation inside.
I always drive carefully, but sometimes the car stalls when the air conditioning is on. This is mainly because when the engine is idling, the exhaust system produces carbon monoxide, a colorless and odorless gas. If you're in an enclosed space like a garage or a tight parking spot with the windows closed and the AC on, carbon monoxide can seep in through gaps in the car or the air conditioning intake. Once inhaled, it displaces oxygen in your blood, leading to symptoms like headaches, nausea, and difficulty breathing. In severe cases, it can cause suffocation due to oxygen deprivation. This isn't a problem with the AC itself but rather the hazards of idling emissions. I recommend using the AC in well-ventilated areas and avoiding prolonged idling in garages. If you must, crack the windows or switch to the external circulation mode to ensure air flow. Safety first—don't let comfort become a killer.
I remember last summer when I drove to an underground parking lot to wait for my family, I turned on the air conditioning and closed my eyes to rest. Not long after, I started feeling dizzy and nauseous. Fortunately, someone reminded me to open the window for ventilation. That’s when I learned that carbon monoxide (CO) from exhaust fumes was the culprit—running the engine in an enclosed space with the AC on recirculation mode allows the gas to accumulate, leading to suffocation. CO poisoning is no joke; symptoms can range from mild fatigue to coma or even death. Here’s what I’ve learned: never idle with the AC on in a closed space; always crack a window for ventilation, even outdoors; and keeping a CO detector in the car adds peace of mind. After years of driving, these small details can be lifesavers.
