A #2: It is not possible to give a precise answer, since central air conditioning systems use condenser and evaporator units separated by variable lengths of tubing, depending on the particulars of an installation. Most units hold 4 to 6 lbs. of refrigerant, depending on the cooling capacity (2 ton to 4 ton). Check the data plate on condenser it will tell you the exact ounces it holds. Then you must adjust the charge up from what the nameplate says to compensate for the piping between the two components of the unit.