Why Does Carbon Monoxide Poisoning Occur When Using Air Conditioning in a Car?
2 Answers
Carbon monoxide poisoning from car air conditioning occurs because the tight sealing of car doors and windows makes it difficult for air inside and outside the car to circulate. When the car is stationary but the air conditioning is still running, the carbon monoxide produced by the engine can accumulate inside the car, leading to poisoning and loss of consciousness, and in severe cases, death. Below is an introduction to car air conditioning: 1. Introduction: The car air conditioning system consists of a compressor, condenser, throttle element, evaporator, fan, and necessary control components, designed to regulate the temperature and humidity inside the car, providing a comfortable environment for passengers. 2. Working Principle: When the compressor operates, it sucks in low-temperature, low-pressure gaseous refrigerant from the evaporator. After compression, the temperature and pressure of the refrigerant increase, and it is sent to the condenser. Inside the condenser, the high-temperature, high-pressure gaseous refrigerant transfers heat to the outside air passing through the condenser, causing it to liquefy. The liquid refrigerant then flows through the throttle device, where its temperature and pressure decrease before entering the evaporator.
Once I took a nap at a highway rest area with the AC on and almost had an accident, so I did some research afterwards. When idling with the AC on, the engine keeps running and produces exhaust fumes. If the car is sealed and using recirculated air, carbon monoxide from the exhaust can seep into the cabin through gaps under the car or in the AC vents. This invisible killer binds to hemoglobin more easily than oxygen and can cause confusion in as little as 20 minutes. It's especially dangerous in older cars with poor seals or when parked in a garage. Now I always crack open a window for ventilation when idling with the AC on—safety first.
