Melbourne homeowners choosing between gas ducted heating and reverse cycle split systems for winter heating face a comparison that has become more nuanced as gas and electricity prices have shifted. This guide covers the operational, cost, and comfort differences between the two approaches — with specific Melbourne context for both systems.
How Ducted Heating and Split Systems Differ
Gas ducted heating
A gas ducted heater burns natural gas in a combustion chamber in the roof space, transfers heat through a heat exchanger to the circulating house air, and distributes the warmed air through ceiling ductwork to every room. The system provides whole-home heating from a single unit. It cannot cool in summer — it is a heating-only system. Gas ducted heating is the dominant whole-home heating system in Melbourne’s established suburbs, installed in the majority of brick homes built between the 1960s and 2000s.
Reverse cycle split system
A reverse cycle split system uses an electric heat pump — an outdoor compressor unit connected by refrigerant pipes to an indoor wall-mounted fan-coil unit. In heating mode, it extracts heat energy from outside air and delivers it inside. In cooling mode, it reverses the cycle. It covers a single room or open-plan space. It provides year-round conditioning but does not serve the whole home without multiple units or a ducted configuration.
Ducted reverse cycle
A third option increasingly chosen by Melbourne homeowners replacing older gas systems is ducted reverse cycle — a heat pump connected to a ducted air distribution system (either existing or new). This provides whole-home heating and cooling from a single system. It connects directly into the existing ductwork infrastructure of a Melbourne home that previously had gas ducted heating.
Running Costs Compared in Melbourne
Running cost comparison for whole-home heating in Melbourne (medium home, 90-day season, 6 hours/day average):
| System | Fuel/Power | Efficiency | Seasonal Cost (2025) |
|---|---|---|---|
| Gas ducted heater, 6-star | Gas at 3.6¢/MJ | 95% | $580–$680 |
| Gas ducted heater, 3-star (older) | Gas at 3.6¢/MJ | 72% | $760–$900 |
| Ducted reverse cycle, 5-star | Electricity at 30¢/kWh | COP 3.0 | $560–$660 |
| Split system (whole home — multiple units) | Electricity at 30¢/kWh | COP 3.5 | $480–$580 |
Running costs for gas ducted heating and ducted reverse cycle are broadly comparable in Melbourne’s 2025 market. The running cost advantage is modest compared to the installation cost difference. The main financial comparison for Melbourne homeowners is typically the capital cost of replacing an existing system, not the marginal running cost difference.
Installation Costs Compared
For a Melbourne home replacing an existing gas ducted heater with existing ductwork in acceptable condition:
| System | Installation Cost (Existing Duct) | New Installation (No Duct) |
|---|---|---|
| New gas ducted heater (Brivis/Rinnai) | $2,500–$4,500 | $4,000–$7,000 |
| Ducted reverse cycle | $4,000–$8,000 | $8,000–$15,000 |
| Split system (single room) | $1,200–$2,800 | $1,200–$2,800 |
For Melbourne homes where an existing gas ducted heater is being replaced and the ductwork is serviceable, the gas-to-gas replacement is by far the lowest capital cost option. The ducted reverse cycle option costs more upfront but delivers year-round conditioning and potentially lower running costs as electricity prices decline with Victoria’s renewable energy transition.
Whole-Home Performance and Comfort
Gas ducted heating delivers consistent whole-home warmth that Melbourne households in large brick homes with multiple bedrooms value highly. The system heats every room simultaneously — important in Melbourne’s winter mornings when every member of the household is getting ready in different parts of the home. A single split system on the wall of the living area does not heat bedrooms or hallways without the doors being left open.
Reverse cycle ducted systems deliver equivalent whole-home coverage to gas ducted but also provide summer cooling through the same infrastructure. This is the increasingly chosen option in Melbourne where summer temperatures increasingly make cooling a necessity alongside winter heating.
Melbourne Climate Considerations
Melbourne’s winter creates specific conditions for each system:
Gas ducted heating is unaffected by outside temperatures — it burns gas to produce heat regardless of whether it is 5°C or 15°C outside. Performance is consistent across Melbourne’s full winter temperature range.
Reverse cycle heat pumps extract heat from outside air. Their efficiency (COP) decreases as outside temperature drops. In Melbourne’s most common winter temperatures (5 to 12°C overnight and 10 to 16°C daytime in the outer suburbs), modern inverter heat pumps still achieve a COP of 2.5 to 3.5 — much better than straight electric heating. On Melbourne’s coldest nights (0 to 3°C in outer eastern and northern suburbs), COP drops toward 2.0, but remains better than direct electric.
For Melbourne households in the outer eastern and northern suburbs (Ringwood, Eltham, Greensborough, Lilydale) where winter nights are consistently colder than inner-city Melbourne, a gas ducted heater’s consistent performance in cold conditions is a genuine advantage over a heat pump for peak winter heating.
Which System Suits Your Melbourne Home
Gas ducted heating suits
- Melbourne homes in the outer eastern and northern suburbs with existing gas ducted infrastructure — Doncaster, Ringwood, Knox, Greensborough, Frankston — where direct gas-to-gas replacement is the lowest-cost option
- Large brick homes where whole-home consistent warmth is the primary requirement
- Households that already have a separate evaporative or refrigerated cooling system for summer
Ducted reverse cycle suits
- Melbourne households replacing an end-of-life gas heater who also want to add summer cooling from the same system
- Inner Melbourne homes where natural gas connection costs are high or connection is not available
- New builds or major renovations where system choice is unrestricted
Split system suits
- Supplementary heating/cooling in a specific room not adequately served by the ducted system
- Single rooms in apartments or townhouses without ducted infrastructure
FreshDuct services all ducted heating types across Melbourne. Call 0431 918 137 for an honest assessment of your options.