What is the working pressure of automotive air conditioning R134a refrigerant?

[LeJake]

Automotive air conditioning R134a refrigerant pressure standards: The normal high pressure should be 1.3-1.7 MPa or 13-17 kg/cm², and the normal low pressure should be 0.15-0.25 MPa or 1.5-2.5 kg/cm². R134a is the most widely used medium-low temperature environmentally friendly refrigerant with excellent comprehensive performance. It is a highly effective and safe substitute for dichlorodifluoromethane and can be used in most applications where dichlorodifluoromethane refrigerant was previously used. A refrigerant pressure gauge, also known as a refrigerant meter or Freon gauge, is used to measure the current pressure in a refrigeration system. It is primarily used to detect the pressure values of the refrigerant at different stages of the system, allowing users to monitor the operational status of the equipment. The outermost scale on the low-pressure gauge represents MPa. For example, if the needle points to "3," the current pressure is 0.3 MPa. The second scale from the outside on the low-pressure gauge represents kg/cm². The red numbers on the innermost scale of the high-pressure gauge represent bar. For example, if the needle points to "20," the current pressure is 20 bar. The conversion formulas for different pressure units are: 1 MPa ≈ 101 kg/cm² ≈ 10 bar ≈ 145 Psi. Measuring the high and low pressures of an automotive air conditioning system: The engine should be idling, and the measurement should be based on an ambient temperature of 35°C. If the low pressure is higher or lower than this range, it indicates improper adjustment of the expansion valve or a problem with the compressor. When the engine throttle is increased, the measured low pressure should decrease with the engine speed. The faster the speed, the quicker the pressure drop, indicating good compressor performance; otherwise, it suggests a compressor fault. Automotive air conditioning refrigerant, commonly known as Freon, is also referred to as "snow seed" or "refrigerant" in the market. It is categorized into environmentally friendly (R134a) and non-environmentally friendly (mainly F12) types. Generally, automotive air conditioning systems do not require refrigerant replenishment for 3-5 years. However, if the cooling effect becomes poor, refrigerant may need to be added. After the air conditioning switch is turned on normally for a while, if the air blowing on your body feels cool and the set temperature is quickly reached, and the outdoor compressor can temporarily stop working like a refrigerator, it indicates normal operation. Otherwise, refrigerant may be needed. Using a thermometer to measure the temperature difference between the inlet and outlet of the indoor unit, if the difference is above 8°C, it indicates normal operation. The larger the temperature difference, the better the air conditioner's performance, with an ideal difference of around 15°C. If the difference is below 8°C, refrigerant may need to be added.