Why does it take more than 10 minutes for the car air conditioning to cool down?

[Rachel]

Here are the reasons why it takes more than 10 minutes for the car air conditioning to cool down: 1. Insufficient refrigerant: The main cause of insufficient refrigerant is usually a leak in the system. If there is not enough refrigerant in the air conditioning system, the amount of refrigerant sprayed into the evaporator from the expansion valve will also decrease. As a result, the heat absorbed during the evaporation of the refrigerant in the evaporator will be reduced, leading to a decrease in cooling capacity. 2. Moisture infiltration in the air conditioning refrigeration system: There is a component in the refrigeration system called the dryer (or receiver), whose main function is to absorb moisture from the refrigerant to prevent excessive moisture from reducing the cooling capacity. However, when the desiccant in the dryer becomes saturated, it can no longer filter out moisture. When the refrigerant passes through the expansion valve's throttle orifice, the pressure and temperature drop, causing the moisture in the refrigerant to freeze in the small orifice. This can lead to restricted refrigerant flow, increased resistance, or even a complete blockage. 3. Reduced heat dissipation capacity of the condenser: Due to the varying working environments of cars, the condenser located in front of the engine can become covered with oil, dirt, or debris, reducing its heat dissipation capacity. Additionally, issues with the cooling fan, such as a loose drive belt, reduced fan speed, or high-speed fan problems, can also impair the condenser's heat dissipation. The solution is to clean the condenser surface with a soft brush and promptly address any fan malfunctions.