Why does the car air conditioning not cool when not accelerating?

[KennedyFitz]

Here are the specific reasons why the car air conditioning does not cool when not accelerating: 1. Dirty air filter: If maintenance has not been performed for a long time, the filter may be too dirty, affecting the cooling efficiency of the air conditioning. 2. Dirty condenser: A dirty condenser can also lead to poor cooling performance. The car air conditioning condenser is located at the front of the vehicle and can be rinsed with a water hose. 3. Insufficient refrigerant: A lack of refrigerant in the air conditioning system's pipelines reduces pressure, resulting in poor cooling. Refill the refrigerant and check for any refrigerant leaks in the air conditioning pipes.

[LaEden]

I encountered this situation while driving - the AC doesn't cool well at idle, but gets cold when accelerating. This is normal because the AC compressor is driven by the engine. At low idle RPM, compression is insufficient, reducing cooling capacity. Sometimes it's due to worn compressor clutch slipping at idle and not fully engaging, or insufficient fan speed leading to poor heat dissipation. Another common issue is slight refrigerant leakage causing insufficient pressure circulation at low pressure. For simple checks, clean dust accumulation on the condenser and ensure the fan operates normally. It's best to perform regular AC maintenance, like replacing refrigerant every two years to prevent aging leaks. During hot weather traffic jams, slightly opening windows can assist cooling to avoid heatstroke risks - driving safety comes first.

[LaAdam]

The AC doesn't cool when idling, a common annoyance I face, caused by the compressor's low RPM. At low speeds, the engine idles around 800 RPM, which also drives the compressor at a lower speed, preventing efficient refrigerant compression. Various reasons: like an aging fan motor lacking power at idle, leading to poor heat dissipation; a dirty or clogged condenser affecting the cooling cycle; or a loose, slipping AC belt. It could also be a minor sensor fault misjudging the temperature and not increasing cooling output. First, check the fan's operation sound and condenser cleanliness yourself. If that doesn't help, visit a professional shop to inspect the compressor and refrigerant. Remember, long-term neglect can damage major compressor components, so early action saves big repair costs.