Why is the high pressure of car air conditioning so high?
3 Answers
The reasons for the high pressure in car air conditioning are as follows: 1. Incomplete evacuation during maintenance, leading to air mixing into the system and increasing the condensation pressure; 2. Use of inferior refrigerant, the condenser electronic fan cannot open normally or the wind speed is insufficient; 3. The condenser is blocked by foreign objects and cannot dissipate heat normally, or the expansion valve is slightly blocked. If both high and low pressure values are measured to be too high, the reasons are as follows: 1. There is air in the system, and the system should be completely evacuated and refilled with refrigerant. 2. The system is blocked, mostly due to expansion valve blockage or failure, and the solution is to replace the expansion valve. 3. Excessive refrigerant, the system should be completely evacuated and refilled with a quantitative amount of refrigerant. 4. The condenser does not cool properly, and the solution is to clean the dirt from the condenser and radiator grille, and replace them if necessary.
I've been driving for over 20 years and have encountered many issues with high AC system pressure, usually caused by cooling system problems. If the condenser or cooling fan gets clogged with dirt or leaves, heat can't dissipate properly, causing pressure to spike. For example, last week when repairing a friend's sedan, the high-pressure gauge shot into the red zone due to a failed fan motor causing system overheating. Overcharging refrigerant is another common issue - excess refrigerant makes the compressor work harder and increases pressure instability. Environmental factors play a key role too, like being stuck in highway traffic during summer heat waves when engine heat transfers to the AC system, worsening pressure buildup. My advice is to regularly clean cooling fins and check fan operation to prevent minor issues from becoming major repairs - safety always comes first.
When I was younger, I often modified cars. High AC system pressure is mostly caused by poor heat exchange efficiency. After the compressor compresses the refrigerant, it should release heat in the condenser. But if the radiator fins are dirty or the fan speed is insufficient, heat can't dissipate, causing pressure to build up. Once during a long summer drive, I noticed the system alarm triggered by excessive high pressure—turned out the condenser was clogged with accumulated insect remains. After cleaning, the pressure returned to normal. Learning from this, I started using an infrared thermometer to regularly monitor heat dissipation components, addressing issues promptly. High pressure not only affects cooling performance but may also damage pipelines, so don't overlook routine maintenance—it saves both money and hassle.
