Ducted, Multi-Split or VRF? Choosing (and Rebating) the Right Air Conditioning System in 2026
This is the question almost every homeowner lands on eventually: gas ducted heating is getting old, the summers are getting hotter, and there are three or four genuinely different system types being pitched with confident opinions about which is “best.” None of them is universally best. Here’s how to actually work out which fits your house.
Reverse cycle vs gas ducted heating
A reverse-cycle system moves heat rather than generating it, which is why it’s dramatically more efficient than gas — typically 3 to 4 times more heat delivered per unit of energy input. It also does both heating and cooling from the one system, where gas ducted heating only ever did the winter half of the job. The running-cost gap has only grown as gas prices have risen relative to electricity, and it’s part of why so many Melbourne homes are replacing ageing gas ducted systems proactively rather than waiting for a breakdown. We covered the head-to-head numbers in
Reverse Cycle Heating vs Gas Ducted Heating and, for anyone actively replacing an old system,
Upgrading Old Gas Ducted Heating to Reverse Cycle Air Conditioning.
Ducted vs multi-head split
Ducted systems heat or cool the whole home from one central unit through ceiling or floor vents — clean-looking, even coverage, but higher upfront cost and less room-by-room control unless you pay for zoning. Multi-head splits put an indoor unit in each room, run off one outdoor condenser, and let you heat or cool only the rooms you’re using — which often means lower running costs for homes where the whole house isn’t occupied at once. As a rough guide: ducted suits open-plan or whole-home comfort where the budget supports zoning; multi-split suits homes where different rooms are used at different times, or renovations where ducting isn’t practical. For the full comparison and sizing guidance, see
Ducted System vs Reverse Cycle and
How to Choose the Right Size Ducted Air Conditioning System.
VRF vs multi-split reverse cycle
VRF (variable refrigerant flow) systems are the commercial-grade cousin of a multi-split — capable of running many more indoor units off a single outdoor unit, with finer control over how much refrigerant (and therefore how much heating or cooling) goes to each zone independently. For a typical house, a standard multi-split is usually the more cost-effective choice. VRF earns its keep in larger homes with a lot of separately-zoned rooms, multi-dwelling properties, or small commercial fitouts, where the efficiency and flexibility gains justify the higher equipment cost. Our earlier deep dive,
VRF vs Multi-Split Reverse Cycle Air Conditioners, covers exactly where that line sits, and
VRF Air Conditioning System explains how the technology itself works.
What about floor heating?
Hydronic or electric floor heating replacement comes up less often now, mostly because reverse-cycle systems have closed most of the comfort gap while costing considerably less to run. If you’re replacing failed floor heating, a multi-head split is the most common like-for-like swap, and it may be eligible for VEU support depending on the specific product — worth checking during your quote rather than assuming either way. See
Replacing Floor Heating with a Multi-Head Split System and
Floor Heating Replacement Under VEU Rebates for the specifics.
Sizing: the mistake that costs you twice
An undersized system runs constantly and still doesn’t keep up; an oversized one cycles on and off inefficiently and costs more than it needed to. Sizing depends on room dimensions, ceiling height, insulation quality, window orientation and glazing — not just square metreage, which is why a proper in-home assessment beats an online sizing calculator every time.
What actually affects your rebate value
VEU rebate value for an eligible reverse-cycle system depends on the product’s energy efficiency rating and the current market value of VEECs (Victorian Energy Efficiency Certificates), which moves over time — it isn’t a single fixed number across every product. Only accredited providers using approved products can generate a valid certificate, so it’s worth confirming both before you sign anything. Our companion post on the VEU program covers exactly how that calculation works.
Before you sign a quote
Confirm three things: the installer is VEU-accredited (ask for the accreditation number, don’t just take their word for it), the specific product model is on the current approved products list, and the quoted rebate is deducted from your price rather than promised as a separate reimbursement later.
