Multi-Split vs Ducted Air Conditioning: Complete Comparison
Quick Verdict
Multi-split suits homes needing 2-4 zones with flexible control and no ceiling space. Ducted suits larger homes with 5+ rooms where aesthetics matter. For 2-3 rooms multi-split is cheaper; for 5+ rooms ducted is more practical.
Side-by-Side Comparison
| Factor | Multi-Split System | Ducted System |
|---|---|---|
| Upfront Cost | $5,000-12,000 (3-4 rooms) | $10,000-20,000 (average home) |
| Running Cost | $350-700/year | $600-1,500/year |
| Cooling Power | Room by room control | Whole home simultaneous |
| Best Climate | All climates | All climates |
| DIY Install? | No | No |
Multi-Split System
One outdoor unit connected to multiple indoor wall-mounted or ceiling cassette units, each with independent control.
Pros
- Independent temperature control per room
- Only runs units in occupied rooms
- No ceiling space required
- Can be installed in stages
- Failure of one unit doesn't affect others
Cons
- Multiple indoor units visible on walls
- Complex refrigerant piping installation
- Limited to 4-5 indoor units max
- Higher cost if doing all at once
- Large outdoor unit with many connections
Ducted System
A central unit in the ceiling/floor distributes conditioned air through ducts to vents throughout the home.
Pros
- Invisible installation - only vents visible
- Cools entire home simultaneously
- Better for large homes (5+ rooms)
- Quieter indoor operation
- Single point of maintenance
Cons
- Requires ceiling space for ductwork
- Higher initial cost
- Less efficient for single rooms
- Zoning requires additional investment
- Major renovation in existing homes
Climate Zone Guide
Hot-Dry Climates (WA, SA, Inland)
Both work well. Ducted evaporative is also an excellent option here at much lower running costs.
Hot-Humid Climates (QLD, NT)
Both work well for refrigerated cooling. Ducted may need dehumidification features for extreme humidity.
Temperate Climates (VIC, NSW, ACT)
Multi-split often more economical - only cool the rooms you use rather than the whole home.
Cost Analysis
Multi-split: $6,000-10,000 for 3 rooms, $350-700/year running. Ducted: $10,000-15,000 for similar coverage, $600-1,500/year running. Multi-split saves 20-30% on running costs when you zone effectively. Ducted is better value for 5+ rooms in new builds. Without zoning, ducted uses 30-50% more energy than targeted multi-split use.
Frequently Asked Questions
Which system is more energy efficient?
Per-room, multi-split is typically more efficient because each unit is sized for its room and only runs when needed. Ducted can be efficient with good zoning but often overcools or runs unnecessarily in empty rooms. Without zoning, ducted uses 30-50% more energy than targeted multi-split use.
Can I add zones to a ducted system?
Yes, but it adds cost. Motorised zone dampers cost $1,500-3,500+ to add and require compatible control systems. Basic ducted systems without zoning cool everywhere or nowhere. Modern smart-zoned ducted systems offer room-by-room control similar to multi-split.
What if the outdoor unit fails?
For both systems, outdoor unit failure means no cooling. Ducted loses the entire home. Multi-split loses all connected indoor units. However, multi-split indoor units failing only affects that room. Consider this redundancy factor if whole-home cooling is critical.
Get a Personalized Recommendation
Not sure which is best for your home? Answer a few questions and get tailored advice based on your climate, home type, and budget.
Get My Free Plan