What is the Appropriate Pressure for Adding Refrigerant to a Car Air Conditioner?
3 Answers
For car air conditioner refrigerant recharge, the appropriate pressure is 150 to 250 kPa for the low side and 1300 to 1500 kPa for the high side. After completing the refrigerant recharge, close the low-pressure manual valve on the manifold gauge, shut off the charging valve on the refrigerant canister, stop the engine, and quickly remove the manifold gauge from the compressor to prevent excessive refrigerant leakage. There are two methods for charging car refrigerant: it can be done from the high-pressure side or the low-pressure side. The car air conditioner is used to regulate and control the temperature, humidity, air cleanliness, and air flow inside the vehicle cabin to a comfortable state, providing a pleasant environment for passengers.
Regarding the refrigerant charging pressure for car air conditioners, I think it's necessary to clarify this matter. Generally speaking, the high-pressure side should be within the range of 15 to 25 kilograms, while the low-pressure side should be maintained between approximately 2 to 3 kilograms. These values can be affected by environmental conditions—for instance, the pressure tends to be higher during hot summers and lower in winter. If the pressure is too low, the cooling efficiency will suffer, resulting in less cool air output; if it's too high, it can easily damage the air conditioning compressor, and in severe cases, may even cause the system to rupture, leading to costly repairs. From my own experience with refrigerant charging, I've found that maintaining the pressure around 20 kilograms delivers the best performance. Before adding refrigerant, it's advisable to check the system for leaks and use a proper pressure gauge for accurate measurements. If you're unsure, it's better not to attempt it yourself—consulting a professional technician for pressure testing is a more reliable approach. Regularly monitoring the pressure during air conditioning maintenance can also help extend its lifespan.
Having driven for so many years, I'm quite familiar with AC refrigerant charging. The high pressure is usually around 25 kg, and the low pressure around 2.5 kg is fine. If it's too high, like 30 kg, the compressor can't handle it and is prone to burning out; if it's too low, like 15 kg, the cooling effect is poor, and the vents don't get cold quickly. Once I DIY charged it to 28 kg, and the AC stopped working on the spot. Later, the mechanic said 25 kg is normal in summer, but don't exceed it. Pressure requirements may vary slightly by car model, like larger SUVs needing slightly higher pressure than small cars. Before charging, check if the cooling has weakened and measure the pressure gauge first. Once the pressure is right, the AC cools instantly, making driving more comfortable. I suggest using reliable tools to try it out, and beginners shouldn't rush to add too much. Regularly check the pressure to avoid malfunctions.
