Refrigerant Charge

[montoy]

In a VRV multi-zone split systems, how do you calculate the additional refrigerant if required? For instance, the developed refrigerant piping is very long, let's say 300 feet.

 

[tys90]

On the design side I've typically seen that the mfg's rep. or mfg designs the refrigerant piping layout and can give you that information. We layout and size fan coils and condensing units, the rest is completed by the rep. or the rep passes it on to the mfg engineering department.