We are going to do a breakdown on how the A/C system on your car works and how to tell if you need a part to be replaced or it's just missing some freeon
So, let's begin :
There are two sides (lines) a high pressure line which is usually the one after the compressor and a low pressure line where the A/C charging port is located.
It works in a loop, The freeon you put goes to the compressor and then goes through a condenser and then goes to the drier although in some cars the drier/accumulator is in the low pressure side. It than goes to the cabin of your vehicle and goes through an evaporator and the blower motor inside the cabin next to the evaporator while still having high pressure it need to go through an expansion valve or an orifice tube which turn the high pressure that comes from the compressor to a low pressure so the compressor can do it's cycle again
So whenever you are having trouble it might just be that the freeon isn't enough to do goo cycles and only one side has freeon it won't feel as cool, another thing you can check is your compressor whenever you turn on the car make sure to not turn the A/Con after you lift your cars hood up turn on the A/C see if the compressor is actually engaging, there are sometimes a sensor that goes to the condenser and if the sensor is bad or the wires of the sensor are bad you won't be getting the full A/C experience. Usually whenever you change the compressor it is also recommended to change the drier or accumulator. The pressure you should be having on the low side is around 50-60 psi and on the high side it should be around 250-270 psi.