Why does the car air conditioner not cool when idling?

[Henderson]

When the car air conditioner doesn't cool while idling but works when driving, it's mostly due to insufficient pressure. It's recommended to visit a repair station for inspection. The specific reasons for insufficient pressure are as follows. Lack of refrigerant: When the vehicle is idling, the compressor speed decreases proportionally with the lower engine speed. If there's a lack of refrigerant, the instant pressure boost won't reach the standard state. This results in excessively low high pressure, affecting the car air conditioner's cooling performance. In this case, simply adding refrigerant will solve the problem. Compressor pressure leakage: Compressor pressure leakage directly causes severely low pressure during idling. This situation requires replacing the compressor.