Is it harmful to idle the car and turn on the air conditioner?
3 Answers
Idling the car and turning on the air conditioner can be harmful. Causes battery drain: While the air conditioner compressor is driven by the engine, the blower fan is powered by the battery. When the car is idling, it may not necessarily charge the battery. Excessive power consumption by the blower fan can lead to long-term battery drain. Risk of carbon monoxide poisoning: Idling with the air conditioner on means the engine is running at a low speed, which can result in incomplete fuel combustion. In such cases, if the windows and doors are closed, the poorly combusted exhaust gases can enter the car, increasing the risk of carbon monoxide poisoning for the driver. Increased fuel consumption: According to related tests, idling with the air conditioner on can increase fuel consumption. When the air conditioner is on, both the air conditioner unit and the condenser need to work, which creates additional resistance for the engine. To maintain stable idling, the engine requires more fuel, leading to higher fuel consumption compared to not using the air conditioner.
Parking with the engine running to use the AC does pose real hazards. As a veteran driver with decades of experience, I've personally encountered this danger. Once while waiting in an underground garage with the AC on, I started feeling dizzy and weak after just 10 minutes – later realizing these were signs of carbon monoxide poisoning from exhaust fumes. That colorless, odorless gas can seep through tiny gaps into the vehicle cabin and prove fatal in severe cases. That's why I strongly recommend only doing this in open, ventilated areas. Beyond safety risks, idling causes incomplete fuel combustion leading to increased carbon deposits that degrade performance, while placing extra strain on the AC compressor that may cause premature failure. With an aging battery, power drains faster and could leave you stranded. For health considerations, it's better to avoid this practice altogether – opt for open windows and fresh air to ensure safe travels.
As a cost-conscious car owner, I must emphasize the economic cost of idling with the air conditioning on. When the engine idles, it consumes a significant amount of fuel—potentially several liters per hour, which translates to tens of RMB wasted. This is especially true in summer when the air conditioning is on, drastically increasing fuel consumption and hitting the wallet hard. The long-term effects are even worse: accelerated carbon buildup in the engine requires frequent cleaning and maintenance, adding extra costs. The air conditioning system, under high pressure while parked, is prone to malfunctions, leading to hefty repair bills. If the battery is low, running the air conditioning might drain it completely, leaving you unable to start the car and requiring a tow truck—another unnecessary expense. To save money and extend my car's lifespan, I now turn off the engine if parked for more than 30 seconds or find a shaded spot to roll down the windows for ventilation—simple and effective.
