What Causes Excessive Pressure in Car Air Conditioning?
3 Answers
The car air conditioning system is a device that cools, heats, ventilates, and purifies the air inside the vehicle, providing a comfortable environment for passengers, reducing driver fatigue, and improving driving safety. The reasons for excessive pressure in the car air conditioning system are as follows: 1. Cooling water: Insufficient cooling water flow or excessively high water temperature. 2. Condenser tube: Excessive dirt buildup or blockage in the condenser copper tubes or fins, leading to poor heat exchange efficiency. 3. Excessive refrigerant: This is indicated by a hot feeling at the exhaust outlet. 4. Air in the system: If there is air in the system, the refrigerant should be completely evacuated and refilled. 5. Expansion valve: A malfunctioning expansion valve is indicated by heavy condensation or frost on the low-pressure pipe. Check if the expansion valve is installed correctly, and if it is, the expansion valve needs to be replaced.
I previously encountered excessively high air conditioning pressure, with common issues being overcharging of refrigerant. The system pressure must be maintained within a reasonable range; adding too much will overload the AC lines. Another problem could be with the cooling system—if the condenser is too dirty or the fan is broken, heat can't dissipate, causing the pressure to rise rapidly. Additionally, if the expansion valve is stuck or the AC lines are blocked, refrigerant can't flow properly, similar to a clogged blood vessel. Extremely high external temperatures can also cause abnormal pressure, especially noticeable after exposure to intense summer heat. If the high-pressure warning light comes on, don't continue running the AC—shut off the engine immediately and go to a repair shop for inspection. Otherwise, damaging the compressor could result in costly repairs. Regularly cleaning the radiator and condenser, along with periodic checks of refrigerant levels, can help prevent this issue.
High AC pressure can occur in several scenarios. Overcharging refrigerant is the most common cause – a professional gauge can immediately show how much it exceeds the standard. Faulty fans are another issue, especially when electric cooling fans stop working, causing a significant drop in cooling efficiency. A condenser surface clogged with dust and debris impedes heat dissipation – I've seen cases where cottonwood seeds completely blocked the grille, causing pressure spikes. Pay special attention to blocked refrigerant lines – a stuck receiver-drier or expansion valve can trigger high pressure. A less common factor is extreme ambient heat, like driving in desert conditions. The solution is straightforward: first turn off the AC to let the system cool, then have a technician check refrigerant levels and cooling components. Never attempt to manually release refrigerant by opening valves – improper handling can be dangerous.