Does running only the air conditioning without driving the car have any impact on the vehicle?
3 Answers
Running only the air conditioning without driving the car does not have a significant impact on the vehicle, but it will increase fuel consumption. Here are some precautions regarding the use of car air conditioning: Select the appropriate fan speed setting: During normal operation, to prevent excessive frosting of the evaporator, which could affect the air conditioning system's performance, the air supply speed and temperature control should not be set to the lowest for extended periods. When the vehicle speed is below 25km/h, the fan speed switch should be set to the low-speed position to avoid insufficient power generation and inadequate cooling. Duration of single air conditioning use: If the interior temperature has reached a comfortable level, the air conditioning can be turned off or switched on intermittently. Prolonged use of the air conditioning can increase the pressure on the condenser, causing wear and tear to the refrigeration system. Therefore, the duration of each air conditioning use should not be too long.
Yesterday, my neighbor Lao Zhang's car broke down because of this. He said he took a nap in the car with the air conditioning on during lunch break, and after two hours, the battery was completely dead. In this situation, running the air conditioning without starting the engine directly leads to rapid battery discharge. The car's air conditioning compressor requires the engine to operate, so when the engine is off, only the blower can be used, which solely relies on the battery's power. A standard car battery may become depleted if it discharges continuously for over an hour, and frequent use like this can also shorten the battery's lifespan. Many cars nowadays come with auto start-stop features, which already place a heavy load on the battery, making it more prone to issues. Especially during hot summer days, some people prefer to rest in parking lots with the air conditioning on, often resulting in the need for emergency jump-starts.
Last time at the 4S shop, I saw a case where the owner always liked to park with the AC on while waiting. They had to replace the battery after just three months. Let me explain the principle: For AC cooling, the engine must drive the compressor. Simply turning on the power only activates the blower mode. What seems like blowing cold air is actually draining the battery, which consumes far more power than playing music. A typical car battery has a capacity of about 60 ampere-hours, and running the blower at maximum speed for two hours can completely drain it. More importantly, deep discharging damages the internal plates, causing permanent reduction in charging capacity. Older cars need extra attention, as aged wiring may also pose short-circuit risks.
