MAXIMUM ALLOWABLE REFRIGERANT CHARGE
AS 1677.2:1998 Refrigerating Systems – Safety Requirements for Fixed Applications, provides a calculation to determine the maximum allowable refrigerant charge, or volume of refrigerant, for an air conditioning system serving an occupied space.
The calculation is based on the maximum allowable concentration of the refrigerant type within an occupied space and the volume of the smallest occupied space of which the whole system refrigerant charge could leak, which is generally an apartment bedroom.
The calculation is only applicable for an apartment bedroom as described above where the indoor unit serving the bedroom has refrigerant contained within i.e. VRF systems.
The refrigerant charge within different VRF system types and arrangements generally vary as a result of:-
- The vertical separation between the outdoor unit and indoor units; and
- The heat transfer methods employed within the outdoor units.