The Two Main Contenders
When it comes to whole-home or multi-room air conditioning, most homeowners are choosing between a split system (or multi-split system) and a ducted air conditioning system. Both can deliver excellent comfort, but they work differently and suit different homes, budgets, and lifestyles. Here's what you need to know.
How Split Systems Work
A split system consists of one outdoor condenser unit connected to one indoor wall-mounted unit. It conditions a single room or zone. A multi-split system extends this concept — one outdoor unit can connect to multiple indoor units in different rooms, each independently controllable.
Best for: Apartments, single rooms, small homes, or homes where you only want to cool specific areas at a time.
How Ducted Systems Work
A ducted system uses a single, central indoor unit (typically in the ceiling or subfloor) connected to a network of insulated ducts that deliver conditioned air to outlets (vents) throughout the home. It's controlled centrally — or by zone if a zoning system is fitted.
Best for: Larger homes, new builds, and homeowners who want consistent whole-home comfort with a discreet, low-profile installation.
Side-by-Side Comparison
| Factor | Split System | Ducted System |
|---|---|---|
| Upfront Cost | Lower (per unit) | Higher (whole-home installation) |
| Running Cost | Lower if only some rooms are used | Higher if whole home runs simultaneously |
| Installation Disruption | Minimal — 2 to 4 hours per unit | Significant — ceiling works, multi-day job |
| Aesthetics | Visible wall unit in each room | Only discreet ceiling vents visible |
| Zone Control | Each indoor unit is its own zone | Requires optional zoning add-on |
| Noise (Indoors) | Very quiet (modern units) | Very quiet from main unit; some duct noise |
| Suitability for Retrofit | Excellent — no major building work | Difficult in existing homes without roof space |
| Whole-Home Coverage | Requires multiple units | Yes — single system covers entire home |
The Case for Split Systems
- Much lower upfront cost — ideal if budget is a constraint.
- Easy to add units over time as your needs grow.
- Perfect for apartments, rentals, or homes without ceiling space for ducts.
- High efficiency when only cooling one or two rooms.
- Minimal installation disruption — typically done in a day.
The Case for Ducted AC
- Delivers a clean, unobtrusive look — no wall-mounted units in every room.
- Ideal for large families wanting consistent comfort throughout the whole home.
- A single controller manages the entire system — simple to operate.
- Adds significant value to a property compared to visible split units.
- Modern inverter ducted systems with zoning can be very efficient when well-configured.
What About Multi-Split Systems?
Multi-split systems offer a useful middle ground — the discreet outdoor-unit-to-multiple-indoor-units setup, without needing ductwork. Each room has its own independently controllable indoor unit, and you only need one outdoor unit (saving space and outdoor wall clutter). The trade-off is that multi-split systems are generally more expensive to install than equivalent individual split systems, and if the outdoor unit fails, all zones go down.
Which Should You Choose?
If you're in an apartment, terrace, or smaller home and want flexibility, a split or multi-split system is almost certainly the better choice. If you're building a new home or undertaking a major renovation and want whole-home comfort with a premium finish, ducted AC — particularly with zone control — is worth the investment. Always get quotes for both options before deciding; the difference in total cost for your specific home may be less than you expect.