How to distinguish between the low-pressure pipe and high-pressure pipe of a car air conditioner?
2 Answers
During refrigeration, the thin pipe is the high-pressure pipe, and the thick pipe is the low-pressure pipe. Here is extended information: 1. The air conditioning system mainly consists of the following components: car air conditioning compressor, condenser, throttle expansion structure, evaporator, and pipelines. 2. Air conditioning compressor: It is the heart of the refrigeration system and the power source that drives the refrigerant to circulate continuously in the refrigeration system. 3. Exhaust pipeline: The connecting pipeline between the compressor and the condenser, which is the high-pressure pipe. The refrigerant flows from the compressor to the condenser. 4. Condenser: A heat exchange device that releases heat from the high-temperature and high-pressure superheated refrigerant vapor discharged by the compressor to the air outside the condenser through metal wall pipes and fins, thereby condensing the superheated gaseous refrigerant into a high-temperature and high-pressure liquid. 5. Throttle expansion structure: It plays a role in throttling and pressure reduction in the entire system and is the boundary component between high pressure and low pressure in the entire system. 6. Evaporator: It is the device where the low-temperature and low-pressure liquid refrigerant, after being throttled by the throttle expansion structure, absorbs heat and vaporizes to achieve the refrigeration effect. 7. Suction pipeline: The connecting pipeline between the evaporator and the compressor. The refrigerant flows from the evaporator to the compressor.
As someone who frequently works on DIY car repairs, distinguishing between the high and low-pressure lines in a car's air conditioning system is quite straightforward. Look at the pipe sizes: the low-pressure line is generally thicker because it connects to the evaporator, operates at lower pressure, and feels cool to the touch. The high-pressure line is thinner, connects to the compressor, operates at higher pressure, and tends to get hot. Here's a tip on their locations: the low-pressure line is usually near the front, close to the windshield, while the high-pressure line is closer to the rear of the engine. After turning on the car's AC, the temperature difference is obvious—the high-pressure line feels warm, and the low-pressure line stays cool. Be cautious when handling them: the high-pressure line has high pressure, so avoid direct contact to prevent burns or refrigerant leaks. For safety, it's recommended to turn off the engine and wait a few minutes before inspection. Use a temperature gun or gloves for protection during checks. These details are practical for DIY repairs and help avoid mistakes that could damage the system.
