How much fuel is consumed when idling with the air conditioning on for 3 hours?
2 Answers
Idling with the air conditioning on for 3 hours consumes approximately 3-4.5 liters of fuel. Below is relevant information: Air conditioning: The air conditioning system mainly consists of components such as the compressor, expansion valve, condenser, evaporator, and blower. Cold air is produced by pressurizing the compressor to liquefy the refrigerant, which then vaporizes, absorbing heat from the air to achieve a cooling effect. Using air conditioning in winter: The warm air used in winter mainly comes from the engine, so it does not consume much fuel. However, summer is different; using the cold air function will definitely consume more fuel. During idling: The vehicle consumes about 2 liters of fuel per hour while idling because the engine is in an idle state with low RPM, resulting in reduced air intake efficiency. Besides fuel consumption and carbon buildup, idling also causes certain environmental pollution.
My own car is a 1.5L sedan, and I usually don't idle with the AC on. But that one time during summer when I was stuck in traffic for three hours, I decided to test it. At idle, the engine runs at around 800 RPM, consuming about 0.7 liters of fuel per hour. With the AC compressor on, it increases by approximately 0.3 liters per hour, totaling 1 liter per hour. Over three hours, that's about 3 liters. This is considered a moderate level—larger displacement SUVs might double that. I think doing this not only wastes money but also leads to carbon buildup and engine damage, and the AC compressor is prone to excessive wear. I recommend avoiding idling with the AC on unnecessarily; it's better to park and rest somewhere. If you must use it, keep it under half an hour and regularly check the battery voltage to avoid draining it.
