Can the Air Conditioning Be Turned On Without Starting the Engine?

[OAshley]

No, the air conditioning cannot be turned on without starting the engine, because the air conditioning compressor cannot operate without the engine running, and thus the air conditioning cannot provide cooling. The car air conditioning cooling system consists of components such as the compressor, condenser, receiver-drier, expansion valve, evaporator, and blower. These parts are connected by copper pipes and high-pressure rubber hoses to form a sealed system. When the cooling system is in operation, the refrigerant circulates through this sealed system in different states. The process is mainly divided into four stages: compression, heat dissipation, throttling, and heat absorption. The compressor draws in low-temperature, low-pressure refrigerant gas from the evaporator outlet, compresses it into high-temperature, high-pressure gas, and discharges it from the compressor. The high-temperature, high-pressure superheated refrigerant gas then enters the condenser, where, due to the reduction in pressure and temperature, it condenses into a liquid and releases a significant amount of heat. The high-temperature, high-pressure refrigerant liquid passes through the expansion device, where its volume increases, and its pressure and temperature drop sharply, exiting the expansion device in a mist-like form. The mist-like refrigerant liquid enters the evaporator, where, because the boiling point of the refrigerant is much lower than the temperature inside the evaporator, it evaporates into a gas. During this evaporation process, it absorbs a large amount of heat from the surroundings, and the resulting low-temperature, low-pressure refrigerant vapor re-enters the compressor. When using the car air conditioning, attention should be paid to the timing of turning the air conditioning on/off, the use of the internal/external air circulation, and the direction of the airflow. It is best to adjust the airflow direction to blow only toward the face, with the air vents positioned horizontally or slightly upward for optimal performance.