How to refill Air-condition Refrigerant (Freon) | AC Gas Charging

Hot summer is the most expensive season on your electric utility bill, especially here in Kolkata. Running your inefficient AC is not pleasurable. If your unit doesn't have the correct amount of refrigerant, your electricity bills will surpass the AC Maintenance cost, and at the same time, it will not cool your home.

If your AC is not cooling properly, the most common reason for that is the coolant/refrigerant in your home or office air conditioner has exhausted. You should call the AC Technician, nearby, immediately.

Though it is possible to Gas Charge your air conditioner unit yourself, you'll need a few specific tools and a little general knowledge about ACs. The process involves risks, so if you are not confident enough, just leave and hir a qualified AC professional I like us.

Things you will need

• Protective Masks, eye goggles, gloves
• Gas charging kit - Freon Repair Kit (reusable injection hose and AC sealant)
• Pressure Gauge
• And general tools

- Make sure to use protective masks, gloves, and eye goggles, Freon is not good for health.

Before doing anything on the unit turn off the power supply. If you need later, switch it on again, but by default always keep it off.

Choose the right type of refrigerant for your unit.

Most of AC used in Kolkata uses refrigerant R-22. And some modern AC's are using refrigerant R410A.

Make sure what refrigerant your air conditioner is using. Because putting the wrong refrigerant in your unit can cause even combustion or injury.

To find the refrigerant you will be using, just check your AC manufacturer’s operating guide. If you can't find your manufacturing guide, check the Unit's cabinet, beside the electrical unit.

Type of Freon can be found on the Cabinet

If you do not see that too, at least manage to find the Model no. of your AC, then Search in the web or call support and ask what refrigerant your AC is using.

- If you are buying new AC, we would recommend one using R410A, as R-22 is an ozone depleting material, and it is slowly phasing out, and number ACs using R410A is increasing.

Diagnose if there is any problem regarding low refrigerant

Before beginning the Gas charging process, make sure the problem of not cooling properly is caused by low refrigerant only.

Broken thermostat too can cause the same problem of AC not cooling properly.

One way to differentiate is, by checking the airflow from the vent if it warm or room temperature. If it is because of low refrigerant, there will be a steadily grow in temperature as the refrigerant keeps depleting. Where in the case of the broken thermostat, or any other issue causing the warm air, the temperature will fluctuate.

Gas charging or refilling refrigerant Freon [R22]

First, we will see how the connections are for the unit and different Components, that you need to know a bit.

Suction port and Liquid Port

In the Outdoor unit, there are two ports or lines for the coolant gas, coming out of the body.

The Larger one is the Suction Line and the smaller one among the two is called the liquid line.

The suction port is three way port and Liquid port is two way port.

You have to attache the hoses from your Gauge manifold to the system ports.

The blue hose (Low Pressure) from the Gauge manifold should be connected to the Suction line or the bigger pipe.

Pressure gauge manifold

We will not connect the red hose from the Gauge Manifold to the Liquid line, keep the HP manifold valve closed.

Turn on the AC unit for about 15 mins, because the AC takes some time to stabilize while starting to run. If you do not run for a little longer, it will not stabilize and you will not get an accurate reading on the refrigerant gauges.

Attach the yellow hose (the one in the middle) of Pressure Gauge to the valve of Refrigerant Container, with the Container in an upright position. There will be a small knob on the bottom of the refrigerant can twist it to open the refrigerant.

R-22 container (left), R410A container (right)

When the unit is off, then the standing pressure on LP Gauge (blue) should be 140-160 psi (for R-22).

And when we turn the machine on, the pressure should be between 60-70 PSI. If it is less than that, this means there is low refrigerant and we need to charge refrigerant.

In this case, we will fill the Gas from the Refrigerant Cylinder. Turn the nozzle on the refrigerant cylinder on.

Fill the Gas slowly

Gas is filled by turning the knob on the LP / Low Pressure Manifold valve. And it should be filled slowly. We fill turn the knob on and off, we will not fill the gas at once. And after a couple of times doing this we will wait for 5 mins, then again we will start filling the same way, if we need more.

If we fill the gas at once, the high pressure might damage the Compressor inside the unit.

When the pressure is between 60-70 PSI (unit is running), we are good.

Now you can remove the Blue hose from the Suction Port. Remove it quickly. As while you removing, it gas gets released through the port.

Close all the caps of the suction and liquid ports.

Watch this video for more:

Check if there is a leakage

Check for leaks. If the tests show that refrigerant is required, check for evidence of leaks and repair them. Leaks can typically be found around any joints or connections:

• Welded or brazed joints
• Pressure ports
• Threaded tubing connectors
• Any place where refrigerant lines may vibrate or rub against the unit chassis or other components.

Find the leakage zone and fix it first. Refer the following video for this:

Thanks for reading.