Allowable charge of R32

The allowable charge in an A2L residential or light commercial air conditioning system is specified in Australian Standard AS/NZS 60335.2.40 and takes into consideration variables such as the room floor area, height of the air conditioner, type of air conditioner, characteristics of the particular refrigerant, the level of ventilation and the application of risk mitigation devices (e.g. sensors, alarms etc).

The common room volume calculation of 20 per cent is not applicable for systems operating on R32. Considering the number of variables and the complexity of the required calculations, the Australian Standard mandates that the manufacturer shall perform the calculations and that the installation instruction will clearly show the resulting minimum floor area that the equipment can be installed into under likely installation scenarios.