What is the standard pressure for automotive air conditioning refrigerant?
2 Answers
Automotive air conditioning refrigerant pressure standards are as follows: 1. When the compressor is running at 1500~2000 rpm: High pressure (discharge pressure) should be around 1.5~2.0 MPa, and low pressure (suction pressure) should be around 0.15~0.35 MPa under normal conditions. The exact values may vary depending on different vehicle air conditioning system configurations and ambient temperature conditions. 2. At idle speed: If the ambient temperature is high (such as under direct sunlight in summer), the high pressure may be slightly higher, reaching up to approximately 2.5~2.8 MPa, but generally should not exceed 3.1 MPa.
Every summer when I drive, if the air conditioning cooling effect in my car decreases, I usually check the refrigerant pressure. The standard values consist of two parts: the high pressure should be around 150 to 200 PSI, and the low pressure should be between 25 to 45 PSI. This also depends on the ambient temperature—for example, on hot days, the pressure might be slightly higher. I remember the last time I measured it with a pressure gauge, at 30°C outside, a low pressure of 30 PSI and a high pressure of 170 PSI were considered normal. If the pressure is too low, it might indicate insufficient refrigerant and a need for a refill; if the pressure is too high, there could be an issue with the expansion valve or compressor. Generally, the vehicle manual provides recommended ranges, and I suggest regular checks to avoid waiting until the AC completely fails before taking action. Always turn off the AC system before checking—safety first. With my old car, I’ve developed a habit of checking it every quarter to avoid getting overheated on the road or spending a fortune on repairs later.
