A five-ton air conditioner holds around 10 to 20 pounds of Freon. In general, an air conditioner system needs two to four pounds of coolant per ton capacity. However, there are many variables that affect exactly how much coolant a particular system needs.
Some of the variables that affect how much coolant is needed include the length of the lineset, the diameter of the tubing in the lineset, the operating efficiency of the unit, the size of the evaporator coil and the type of system. Most units come fully charged and only require additional Freon to be added if the system develops a leak.