
Running the AC while the car is stationary can damage the vehicle. Impacts of running the AC while stationary: It increases the condenser pressure, causing wear to the cooling system and leading to carbon buildup in the engine. Additionally, after turning on the AC, the engine needs to cool down the heat from the AC condenser, which keeps the cooling fan running continuously. If there are issues with the cooling or heat dissipation systems, it can result in high engine coolant temperature, potentially harming the engine. Precautions for using the car AC: Turn off the AC switch during startup and rapid acceleration, avoid setting the AC temperature too low, adjust the air vent direction properly, refrain from immediately turning on the AC after the car has been exposed to intense sunlight, and always turn off the AC before shutting down the engine when parking.

I think keeping the car stationary with the air conditioning on can be quite damaging to the engine. Since the engine operates insufficiently at idle, it’s prone to increased carbon buildup, and over time, this may lead to overheating issues or even component wear. I remember one summer when I waited too long in the car with the AC on for a friend, and later during a repair, I found the spark plugs covered in carbon deposits. Generally, running it for a few minutes is fine, but if it’s over an hour continuously, the increased load will strain the battery as well, not saving electricity but harming the car instead. It’s advisable to avoid prolonged idling with the AC on—for safety, you can open the windows for ventilation or turn off the engine to rest, protecting the car and saving fuel. Regular maintenance to check the engine’s health is crucial, especially for older cars, as this habit can significantly extend the vehicle’s lifespan.

The most annoying thing about idling with the AC on is the wasted fuel. I've calculated that idling for an hour with the AC running can burn two to three liters of fuel, equivalent to dozens of dollars flying away. Over time, this significantly increases fuel consumption, not only hurting your wallet but also causing more harmful emissions due to incomplete engine combustion, polluting the air. I'm in the habit of rolling down the windows or turning off the AC when waiting in the car, saving money and being eco-friendly. If I must use the AC, such as in extreme heat to prevent heatstroke, I limit it to short bursts of ten minutes to avoid draining the battery. Cars are designed to move, and keeping them stationary while putting extra load on the system is never good. For the sake of my car's longevity, I'd rather endure a bit of heat.

If the car is stationary with the AC on, the battery load will increase. The engine's idling power generation efficiency is low, and the high power consumption of the AC may cause unstable battery voltage. It's fine for short periods, but prolonged use can accelerate battery aging. I once left the AC on for two hours while parked at night, and the next day the car had difficulty starting. Remember to regularly check the alternator and battery condition, and replace them as needed to reduce risks.


