Leaving your car running with the air conditioning (AC) on for about an hour without moving it is generally not ideal for several reasons:
Fuel consumption: Keeping the engine running unnecessarily for an extended period will consume fuel. It's not an efficient use of resources, and it may lead to unnecessary expenses.
Engine wear and tear: Idling the engine for long periods can cause increased wear on engine components. The engine is designed to be most efficient while in motion, and idling can lead to incomplete combustion, which can result in the buildup of carbon deposits and other issues.
Battery drain: Running the AC and other electrical systems while the engine is idling can put a strain on the car's battery, especially if the battery is older or already weakened.
Overheating: Although running the AC can help keep the cabin cool, idling for extended periods can lead to engine overheating, especially in hot weather or if your car's cooling system isn't functioning optimally.
Environmental impact: Unnecessary idling contributes to air pollution and greenhouse gas emissions, which can be harmful to the environment.
If possible, it's best to turn off the engine when you don't need to use the car, especially during extended breaks. If you want to keep the cabin cool, you can consider using a sunshade on the windshield and windows or parking your car in a shaded area. Additionally, some modern cars have a feature called "auto stop-start," which automatically turns off the engine when the car is stationary and restarts it when you press the accelerator pedal. This feature helps save fuel and reduce emissions.
If you need to take a break during a long drive and want to use the AC, it's generally better to find a safe parking spot, turn off the engine, and then turn it back on when you're ready to continue driving. This way, you can reduce fuel consumption, save wear on the engine, and be more environmentally friendly.