If the air condition system refrigerant has doesn't cool as well as it should, it may be necessary to perform an air conditioning recharge. Before any AC system repairs are performed, the system must be free of moisture and contaminates and leaks should already be repaired.
To recharge the AC system, gauges are attached to the AC system to measure pressures in the system, and refrigerant is added as needed.
AC systems should be worked on only by competent, trained personnel, and the manufacturer recommendations should be followed. If the air conditioning is improperly recharged, then it could cause permanent damage to the air conditioning system.