You can keep your car's air conditioning (AC) system on while the engine is running and the car is parked for as long as you need or want, provided that the engine is in good working condition and there is sufficient fuel in the tank. Modern car engines are designed to handle idling for extended periods without any issues.
However, there are a few considerations to keep in mind:
Fuel consumption: Idling with the AC on will consume fuel, and this can add up if you leave the engine running for an extended period. If you plan to keep the AC on while parked for a long time, it's a good idea to monitor your fuel level or consider turning the engine off if it's not needed.
Battery: The AC system puts additional load on the car's battery. If you keep the AC on while the engine is off (key in the accessory position), it may drain the battery over time, potentially causing starting issues later. If you plan to use the AC without the engine running, it's better to keep the engine idling to avoid battery drain.
Environment: If you're concerned about the environmental impact of idling, consider turning the engine off when you don't need the AC. Prolonged idling contributes to unnecessary emissions and air pollution.
Overheating: Modern cars are designed with cooling systems that can handle idling, but in very hot weather conditions, there's a slight risk of overheating if the engine is idling for an extremely long time. This risk is relatively low, but it's something to be mindful of, especially in extreme heat.
In summary, you can keep your car's AC on while the engine is running and the car is parked, but be mindful of fuel consumption, battery health, and environmental impact. If you plan to stay parked for an extended period, consider turning off the engine periodically or when the AC is not needed.