The Best Ducted Air Conditioning System for Your Two-Storey Melbourne Home: A Complete Guide

Why Ducted Air Conditioning Suits Two-Storey Homes

Ducted air conditioning provides a consistent level of heating and cooling throughout your entire home. Operating from one central unit, a ducted system can be custom designed for your home’s layout. Zoning controls allow you to direct the flow of air to specific areas as needed, making it more energy efficient. This makes it suitable for two-storey homes where managing temperature differences between levels is important. 

During summer, heat pools up on the second floor, making it unbearably hot, while during winter, warmth from downstairs drifts upstairs, making the ground floor chilly. A properly designed ducted system with zoning capabilities overcomes these natural thermal challenges, ensuring both levels maintain comfortable temperatures year-round.

What to Consider Before Deciding on Ducted Air Con for Your Double Storey Home

Installing ducted air conditioning in a two-storey home requires careful planning. The ducts are run vertically from the roof space through wardrobes and cupboards, or in some cases, through specially designed bulkheads. Duct sizes are typically 250mm in diameter, though larger houses requiring more air may use 300mm ducting.

For new builds, installation is straightforward as provisions for ductwork can be incorporated during construction. However, in existing two-storey homes, the ducts cannot be run horizontally between floor joists in the ceiling of the first floor as the ceiling will have already been plastered, meaning vents on the lower storey must be directly below the closet or cupboard that vertical ducts run through.

Mitsubishi Electric

Mitsubishi Electric, with nearly 50 years of experience in the Australian industry, offers a comprehensive range of units designed to deliver exceptional comfort and energy efficiency. Their systems are particularly notable for handling Melbourne’s temperature extremes.

Key Features:

• NEW Mr Slim large capacity ducted units in R32 refrigerant, with 18kW models able to connect to single or three-phase power, making it one of the largest single-phase models available
• Five-stage external static pressure conversions and four fan speed selections for ultimate comfort solutions
• Capacity range from 5kW to 24.5kW
• Integration with optional Lossnay heat recovery ventilation for improved indoor air quality
• Guaranteed cooling performance at high ambient temperatures

Best For: Homes requiring flexible installation options and superior performance in extreme weather conditions. Homes with narrow access, the slim outdoor unit measures 1338 x 1050 x 330.

Daikin consistently ranks as one of Melbourne’s most trusted ducted air conditioning brands. Their ducted systems provide discreet air conditioned comfort that can be installed in new homes or tailored to suit existing ones, with only the controller, return air and discharge grilles visible inside your home.

Key Features:

• Premium Inverter series with variable refrigerant temperature technology that continuously adjusts both inverter compressor speed and refrigerant temperature for highest levels of seasonal efficiency
• Heating Focus models available from 18 to 24kW with improved heating performance, ideal for cold climates such as Melbourne
• Capacity range from 7kW to 24kW to suit various home sizes
• 5-year parts and labour warranty on all residential installations
• Smart home integration capabilities with Wi-Fi control options via Daikin AirHub controller or Daikin Airbase app.
• 7-16kW models use R32 refrigerant, 18-24kW models use R410A refrigerant.

Best For: Homeowners seeking premium efficiency with proven reliability and extensive local support network.

Bonaire has recently introduced ducted air conditioning to their line up with an impressive 7 year warranty, and high efficiency units eligible for VEU rebates. Their systems provide excellent value without compromising on essential features, and are popular in Melbourne’s northern and western suburbs.

Key Features:

• Available in 10.5 to 16kW models all with R32 refrigerant
• Optional WiFi controller available
• Can be operated in -15°C to 50°C conditions
• Energy-efficient operation with reduced running costs in ECO mode
• Wide availability of parts and service technicians
• Impressive 7 year warranty (compared to 5 years on other brands)

Best For: Budget-conscious families seeking reliable performance and widespread service support.

Sizing Your Ducted System Correctly

Proper sizing is critical for efficiency and comfort in a two-storey home. For a typical Melbourne home with 2.4 metre ceilings, multiply the daytime cooling area by 150 watts to determine capacity required in kilowatts, or multiply by 160 watts for 2.7 metre ceilings.

For a typical four-bedroom, two-storey Melbourne home, you might need:

• Total floor area: approximately 200-250m²
• Daytime living areas: 100-120m²
• Recommended capacity: 12.5kW to 16kW

The sweet spot for coverage is around 70%, meaning the air conditioner should have the power to cool at least 70% of the home at once. This ensures efficient operation without oversizing, which can lead to short cycling and poor humidity control.

Feel free to play around with our air conditioning size calculator. When you’re ready to get a free quote for your home, don’t hesitate to reach out!

Zoning Capability

Zoned ducted heating and cooling use gates built into your ductwork to control the flow of air, allowing you to overcome the movement of heat without having to install multiple systems. This is essential for managing temperature differences between floors.

Inverter Technology

All recommended brands now feature inverter technology, which adjusts compressor speed to maintain consistent temperatures while reducing energy consumption by up to 30% compared to fixed-speed systems. Learn more about inverter air conditioners.

Smart Controls

Modern systems offer Wi-Fi connectivity and smartphone apps, allowing you to adjust temperatures remotely and set schedules for different zones throughout the day.

Approximate Installation Costs for Double Storey Homes

The cost for purchasing a ducted refrigerated air conditioning unit with professional installation starts from around $10,000. Upgrades that increase costs include WiFi controllers, extra zones, extra sensors, long pipe and ducting runs etc.

For a typical four-bedroom, two-storey Melbourne home, expect to invest:

• Supply and installation: $10,000 – $15,000
• Annual servicing: Approximately $350
• Running costs: $600 – $1,200 per year (depending on usage and energy tariffs)

Making Your Final Decision

When selecting the best ducted air conditioning system for your two-storey Melbourne home, consider:

1. Your budget – Both upfront and long-term running costs. Some of the more premium brands cost more upfront, but have cheaper running costs.
2. Energy efficiency – Look for high star ratings and inverter technology
3. Local support – Choose brands with strong Melbourne dealer networks (like the one’s we’ve featured here)
4. Specific needs – Air quality concerns, extreme temperature performance, or integration with existing systems
5. Home design – Roof space limitations, ductwork routing possibilities, and aesthetic preferences
6. Consider alternatives – You might find a multi-head system better for your double storey home. Read our post on multi head split systems vs ducted for more information.

What Will You Decide for Your Two Storey Home?

With the right ducted air conditioning system properly installed and maintained, your two-storey Melbourne home will remain comfortable through every season – from the coldest winter mornings in July to the hottest summer days in January. 

For most four-bedroom, two-storey homes in Melbourne, Daikin’s Premium Inverter series (14-16kW) offers the best overall combination of efficiency, reliability, and local support, however, this premium brand has a higher price tag. 

If you’re prioritsing air quality, Panasonic’s systems with nanoe™X technology are exceptional, and backed by Japanese engineering. Mitsubishi Electric offer space saving slimline designs, and are a quality air conditioner with a reasonable price point. 

For those on a tighter budget, Bonaire provides reliable performance at lower costs. We also offer 36 months interest free financing via ZipPay to approved purchasers. Just ask us and we’ll discuss different options with you. 

If you’d like a no obligation quote, don’t hesitate to reach out to the team at ExtrordinAir today. We are licensed under the Australian Refrigeration Council (AU29403) and Victorian Building and Plumbing Commission for all air conditioning installations. We’d be more than happy to offer you a free quote and advice on the best heating and cooling solution for your Melbourne home.