This is quite a complex question, as a lot depends on how the A/C is used. For example, if you’re only cooling one room in the home, a single split system will cost less to run than a ducted system (which will cool the whole house). Conversely, if you want whole-house cooling, ducted A/C costs less to run. Furthermore, although ducted A/C will pump out air at a constant temperature into each room, there can be significant temperature variations between rooms due to variables such as aspect, level of insulation, whether windows are left open, room size or whether the room is on the ground, first or second floor. Because the most energy-efficient form of A/C varies depending on requirements and the property, we recommend calling us for a FREE assessment. We can then advise on the system that’s going to be most cost-effective, with the lowest running costs, for your circumstances.