What Causes Low High Pressure in Car Air Conditioning?
2 Answers
Car air conditioning low high pressure is caused by: 1. System issues: refrigerant leakage, blockage, dirty heat exchangers; 2. Electrical issues: abnormal operation of compressor, solenoid valve, four-way valve, or motor. Under normal air conditioning operation, the low pressure should be around 3bar and high pressure around 15bar. Note this refers to normal operation when the cabin blower is set to the fourth speed, radiator cooling fan runs at high speed, and external condenser has good heat dissipation. The car air conditioning system is designed to cool, heat, ventilate and purify cabin air, providing passengers with a comfortable environment, reducing driver fatigue and improving driving safety.
I've encountered the issue of low high pressure in car air conditioning several times, usually due to insufficient refrigerant, meaning there's a refrigerant leak. If there are too many leakage points in the system, the pressure won't rise, and the AC blows hot air, making it feel like the AC isn't on at all. Compressor failure can also cause insufficient high pressure, such as internal wear or a damaged electromagnetic clutch. Or, the AC lines might be blocked, especially if the condenser is too dirty or the expansion valve is stuck. A non-functioning condenser fan can also lead to this, as poor heat dissipation in high-temperature environments exacerbates the issue. I recommend not ignoring these problems—driving in hot weather is unbearable. Get the pressure gauge and safety valve checked at a professional shop as soon as possible. Regular cleaning of the condenser and fan can prevent many issues.
