Variable Refrigerant Flow (VRF) air conditioning systems are normally used in commercial applications but now LG has made them sufficiently cost effective to use in your home, due to technical improvements & introducing smaller domestic home-sized systems.
If you have 3 or more indoor units to connect, then a VRF system may be your best option, close enough in price to a ducted system supplied and installed to be an attractive option for your home.
VRF systems allow many indoor units to be connected to just one outdoor unit and the system determines how much refrigerant to flow to each indoor unit for optimal performance, taking account of the distance from the outdoor unit. If required, you can connect indoor units a long way from the outdoor unit without balancing problems.
VRF systems are more efficient with less heating & cooling losses than ducted systems. They are also easier to install & provide a solution if you don’t have at least 300mm of ceiling space to run ducting.
These systems lend to interesting designs that may give you more ceiling height by using concealed indoor units above robes or cupboards.