Air conditioner service! How is Split AC Gas Filling Done?

Does your AC technician suggest an AC gas filling? Step-by-step, important points for air conditioner refrigerant filling

This article is for you. Having confirmed that your air conditioner is well maintained, it’s alright. You will need a refill for your air conditioner to enable you to keep moving in case the level of gas in the air is low. Air conditioning gas is a toxic chemical used to help in the cooling process. They contain the coils of the air conditioner, which help humidify the indoor air.

We have different types of gas that are used to refill the AC. The gas makes air conditioning possible since it is contained in the coils of an air conditioner. These liquid gases are very efficient because they cool and dehumidify the indoor air effectively. However, the process of refilling the AC gas is very dangerous and requires a lot of care and safety measures.

The procedure of AC gas filling: It’s very important to highlight a few types of AC gases since not all air conditioners work with a common refrigerant.

Types of AC gases

Puron (R410A): This type of gas is hydrofluorocarbon and is commonly used in the latest air conditioners. It doesn’t affect the ozone layer and is embraced by many as residential air conditioning. The gas is very efficient at heat transfer, helping the AC unit do less work for a comparable amount of cooling. The gas also works at very high pressure.


Freon (R22): this type of gas is hydrochlorofluorocarbon. It contributes to ozone layer reduction. This type of gas is not recommended for residential air conditioners. It’s known to have harmful effects on the environment.

R32 refrigerant is mildly flammable, has low global warming potential, and has zero ozone-depleting potential.

It’s always good to note that the refrigerant in air conditioners is toxic and can easily cause frostbite. So, kindly, it’s very important to read below the highlighted precautions you need to take before you begin the process of refilling the AC gas. These liquid gases are very efficient because they cool and dehumidify the indoor air effectively. The process of refilling the AC gas is very dangerous, and one is called to care.

Care measures

  • Always ensure that you are wearing gloves.
  • Your eyes are vital, so kindly wear protective eyeglasses.

Equipment required

  • Refrigerant
  • A Vacuum pump
  • A horsepower
  • A set of AC manifold gauges.

How is AC Gas Filling Done? AC Gas Filling Procedure

r22 ac coolant
  • With factual tools and safety attire, filling AC gas is usually a straightforward thing. To begin with, you will be required to check and locate the low side, which is the suction line, and the discharge line, which is the high side of the air conditioner.
  • The two are set behind a window AC and in a riven AC in the out-of-doors unit. The suction line is cool to the touch and is placed just above the discharge line. However, the discharge line is warm to the touch, and it’s located under the suction line. To recharge the gas in the AC, you will use the suction line.
  • To enable you to fix the lines, you will be required to unscrew the bolts on the suction line. Loosen the screws to let the gas out since these screws act as the valve used to draw the gas. The screw is efficient, and it won’t let the refrigerant flow in or out until it is closed. However, to enable you to refill the AC gas, you will have to loosen the screw.
AC Vacuum Pump
  • To enable you to connect the blue hose of the AC, you will have to remove the bolt fixed on the left side and then connect the blue hose of the AC manifold gauge to the port you unscrewed. Ensure that the yellow pump is connected to the vacuum pump. Make sure that all the air is removed from the system. While handling this step, be more careful since if any moisture penetrates inside the compressor, it will damage it.
  • Ensure and confirm that all the valves of the AC manifold gauge are well closed. Thereafter, you link the yellow hose to the refrigerant tank. Slightly loosen the yellow hose at the manifold end. Make sure that the hose doesn’t have any air inside, and it’s always good to confirm the same by opening and closing the cylinder knob. This will help to release any air that may be inside the pipes. After doing that, remember to tighten the yellow hose.
  • Before turning on the AC, open the low side knob of the manifold and then close it. After doing that, turn on the AC and wait until the compressor kicks in.
  • At this point, it’s advisable to keep a closer eye on the gauge

When the compressor starts, you will have to open and close it for a few seconds. Also, monitor where the pressure settles in the gauge; you will need to keep on opening and closing it for efficacy. You will have to repeat the procedure until the pressure settles between 60 and 70 psi.

  • Always remember that if you release all the gas at once, You can easily cause damage to the compressor, that’s why the AC refrigerant is filled in small amounts.
  • Close the manifold valve on reaching the 60–70 PSI range. Then you close the manifold valve and close the refrigerant tank knob. Lastly, you unscrew the blue hose from the suction line and the yellow hose from the refrigerant tank.
Tools for AC gas filling

Reasons for AC gas leakage

Listed below are the reasons why we have gas leakage.

  • The improper installation
  • Manufacturing defects
  • Accidental damage to a copper pipe or rusted valves.
  • Wear and tear.


As written above, now you know everything about AC gas leakage, refilling, the types of gases used, and the precautions to take. Always ensure to follow the procedure given in AC Gas Filling.

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