Ducted Air Conditioning

The honest answer: for the right home, yes. For the wrong home, not necessarily.

A ducted system costs more upfront than a single split-system AC; however, comparing a ducted system to one split system is the wrong comparison. Most Sydney homes needing whole-home comfort are looking at 4–6 rooms. At that scale, you’re either buying multiple split systems or one ducted system.

Running multiple split systems means multiple sets of filters to clean, multiple services to book, remotes to manage, and individual wall units visible in every room. A ducted system gives you one central controller, one annual service visit, and nothing on the walls at all.

Upfront cost vs long-term value

Ducted systems are a long-term asset. A well-installed system typically lasts 15 to 20 years, and over that period the cost-per-year of comfort is substantially lower than most people expect when they first see the quote.

Inverter technology also means the system uses only the energy it needs to hold a set temperature, rather than cycling on and off at full power. Combined with zoning, you’re only conditioning the rooms actually in use, which keeps running costs manageable.

When ducted AC might not be the right call

Ducted air conditioning isn’t the right answer for every situation. It may not suit you if:

• Your home has no accessible roof cavity (some low-pitch or flat-roof properties need alternative solutions)
• You only need to condition 1 or 2 rooms
• You’re renting and can’t modify the property
• Your budget requires a staged approach, where a split system in key rooms now makes more practical sense

Do any of those apply? Our team can recommend the right AC system for your situation during a site inspection. Book a free site inspection.

We supply reverse-cycle ducted air conditioning systems from known brands such as Daikin, ActronAir and Mitsubishi. This allows the same unit to cool your home in summer and provide heating in winter. One system, one installation, year-round comfort.

How reverse cycle ducted air conditioning works

A reverse cycle system uses a refrigerant cycle that can run in both directions.

• In cooling mode, it extracts heat from inside your home and expels it outside.
• In heating mode, it extracts heat energy from the outdoor air (even cold air contains heat energy) and moves it inside. This is why it’s called a heat pump: it moves heat rather than generating it.

A standard ducted system conditions your whole home, but a zoned ducted system lets you decide which parts of your home get conditioned, and when.

How does zoned ducted air conditioning work?

• Each zone corresponds to a room or area of your home (e.g. master bedroom, living room, upstairs)
• A motorised damper inside the duct for each zone opens or closes based on which zones you’ve activated
• A zone controller (usually a wall panel or touchscreen) lets you adjust each zone independently
• You can set different temperatures per zone, or simply turn zones on and off as needed

How many zones do I need?

This depends on how your household actually uses the home, instead of just how many rooms it has.

• 2–3 bedroom homes: 2 to 3 zones is usually enough. A common split is living areas as one zone and bedrooms as another.
• 4–5 bedroom homes: 3 to 5 zones is typical. Upstairs/downstairs splits, or separating the master from minor bedrooms, are common configurations.
• Larger or open-plan homes: Zone counts vary more. An open-plan living, dining and kitchen space usually functions as a single zone despite covering a lot of floor area.

We map zones during the site inspection based on your floor plan and how you live in it. For more detail on configurations, learn more about our zoned ducted systems.

What is MyAir zoning?

MyAir is a smart zoning and control system developed by ActronAir for use with compatible ducted systems. It replaces the standard wall controller with a touchscreen panel and smartphone app, giving you full remote control over your ducted system.

What MyAir adds over a standard zone controller:

• App control: Adjust zones, set temperatures, and turn the system on or off from your phone, whether you’re on the couch or on the way home
• Scheduling: Pre-cool the house before you arrive, or wind down after everyone’s in bed
• Room-by-room management: Each zone shows its current temperature and can be individually adjusted from the app
• Usage tracking: MyAir logs energy usage by zone, so you can see where the system runs hardest and dial it back

MyAir is compatible with the Neo ducted range and select other systems. If smart zoning is a priority for you, get in touch and we’ll match you to a compatible system.

Ducted air conditioning for houses

A standalone house is the most natural application for a ducted system. A pitched roof provides space for the indoor unit and ductwork, and the floor plan maps cleanly to zones.

For existing homes, we start with a roof cavity assessment to confirm clearance and map duct routing before quoting. Most Sydney houses are suitable for a retrofit ducted install, though complexity varies. For new builds and renovations, early involvement is the better approach: coordinating with your builder before the ceiling is closed means cleaner duct runs and no structural compromises in the finished result. Learn more about our full residential air conditioning services.

Ducted air conditioning for apartments and strata

Apartments are more complex territory, and the main practical challenge is the ceiling cavity. Many apartments in multi-storey buildings have concrete slab ceilings with no space for ductwork. In those cases a ducted system typically isn’t feasible, and a cassette or split system is the practical alternative.

For lower-density strata properties such as townhouses, villa units and ground-floor apartments with roof access, ducted is sometimes viable. If the structure allows it, the next consideration is strata approval.

What to check before buying a ducted system in a strata property:

• Body corporate approval: Most strata schemes require written approval before any work affecting the building’s exterior, roof or common property. This includes outdoor unit placement and any roof or wall penetrations.
• Noise and placement rules: Some by-laws restrict where outdoor units can be installed based on proximity to neighbouring lots or noise impact.
• By-law review: A read of your strata by-laws before quoting is always worth it. We can advise on what the installation involves physically, but strata approval is the owner’s responsibility.

Read more about our air conditioning for apartments service, including what’s possible in strata-managed buildings.

Ducted air conditioning for new builds and constructions

New builds are where ducted systems perform at their best. When air conditioning is designed into the build from the start, duct runs are shorter and more efficient, the indoor unit sits exactly where it should, and zones are mapped to the floor plan before anything is locked in structurally.

We work with builders, developers and owner-builders across all project scales, from single dwellings to multi-lot developments. We coordinate with the build program, supply and install to specification, and commission the system ready for handover.

Commercial ducted air conditioning

For offices, retail tenancies, warehouses and mixed-use spaces, ducted systems are often the right call when the ceiling structure allows. Commercial applications involve different capacity requirements and load profiles than residential applications, and system selection reflects this.

We handle commercial air conditioning across Sydney, including ducted installations for fit-outs and tenancy upgrades. If your project is commercial in scale, reach out directly and we’ll scope what’s involved.

Finance is available on both residential and commercial ducted installations, so you can get the system you need now and spread the cost over time. Through our finance partner you can borrow up to $15,000 with no fees and up to 10 years to repay.

If you’d like to understand what a monthly repayment looks like for your quote before committing, ask us when you book your site inspection and we’ll run through the numbers with you.

View finance options

Ducted air conditioning servicing

• Filter inspection and cleaning
• Indoor unit inspection
• Outdoor unit check
• Zone damper and controller test
• Airflow check
• System commissioning check

For more on our ongoing maintenance, see air conditioning servicing.

Ducted air conditioning repairs

• Loss of cooling capacity across all zones
• One zone not responding, stuck open or closed
• AC system not responding to controller inputs
• Duct damage
• Drainage blockages

For air conditioning repairs across Sydney, our team is available on call.

Why is my ducted air conditioning not cooling?

If your ducted system is running but the house isn’t cooling down, one of these is usually the cause:

• Dirty return air filter: A blocked filter is the most common cause of poor cooling. It restricts airflow to the indoor unit and reduces AC efficiency. Check and clean the filter first.
• Zones set incorrectly: If a zone isn’t open or the controller is set to the wrong mode, you may be heating instead of cooling, or the affected rooms may simply be switched off.
• Refrigerant loss: If the system has lost refrigerant it loses its ability to cool effectively. This requires a licensed technician to diagnose and rectify.
• Blocked return air grille: The return air grille needs clear space around it to draw air efficiently. Furniture or curtains placed too close will starve the system.
• Undersized system: If the system was incorrectly sized for your home it will struggle on hot days regardless of its condition. A site assessment will confirm whether this is the issue.
• Duct damage: Air escaping into the roof cavity before it reaches the vents means rooms don’t cool even when the system is working correctly.

If a filter clean doesn’t resolve it, call 1300 507 892 and we’ll diagnose it properly.

Ducted air conditioning making noise?

A ducted system should be close to silent in the living areas. If you’re hearing noise, here’s what it usually means:

• Rattling or vibrating ducts: Often a loose flex duct connection, a duct touching a structural element, or debris in the ductwork. Usually straightforward to locate and fix.
• Banging or clunking at startup: Can indicate a loose component in the indoor unit or, in older systems, worn fan bearings. Worth having a technician check if it’s persistent.
• Whooshing or whistling at vents: Usually a sign that too many zones are closed simultaneously, forcing high-velocity air through fewer vents than the system is designed for. Adjusting the minimum zone count on the controller typically resolves this.
• Loud or persistent noise from the outdoor unit: Some compressor noise at startup is normal. Grinding, rattling or knocking that doesn’t settle warrants a service call.
• Squealing: Usually a fan belt or bearing issue in older systems. Needs attention before it becomes a full failure.

Ducted air conditioning not turning on?

Before calling a technician, run through this checklist:

• Power at the isolator: Check the external isolator switch (usually near the outdoor unit) is in the ON position. It can be accidentally knocked off.
• Circuit breaker: Check your switchboard for a tripped breaker on the AC circuit.
• Controller settings: Confirm the controller is set to the correct mode (cool or heat, not fan-only), that the set temperature is actually calling for action, and that at least one zone is active.
• Zone settings: If all zones are set to off, the system may not start even if the main controller is on.
• Fault code on the controller: If a fault code is displayed, check our error codes page for the likely cause before calling.

If none of those resolve it, the system needs a technician. Don’t attempt to reset it repeatedly: if a fault is present, continued cycling can cause further damage.

Running costs depend on several factors, and a well-set-up system with zoning is often cheaper to run than people expect. They are shaped by how your system was specified, how you use it, and how well it’s maintained.

What affects ducted AC running costs?

• System size (kW capacity)
• Energy Star rating
• Zoning
• Usage patterns
• Home insulation
• System age and condition

Inverter technology and why it matters

A non-inverter system is either on at full power or off, while an inverter system adjusts its output continuously to match what’s needed, running at low capacity to maintain a set temperature rather than switching off and on at full power repeatedly.

The result is more consistent comfort and lower electricity consumption, particularly over a long summer day where the system runs for extended periods. Combined with zoning, an inverter ducted system in a well-insulated Sydney home can be cost-effective to run.

Summer vs winter running costs

Sydney’s climate means ducted systems do more cooling work than heating across the year. A reverse cycle ducted system handles both from the same unit:

• Summer cooling: Cooling requires more compressor work than heating in a heat-pump system. Sydney’s hot summers mean longer daily run times during peak season.
• Winter heating: Reverse cycle heating is significantly more efficient than electric resistance heating. A heat pump moves heat rather than generating it, producing around 3 to 4 units of heat energy for every 1 unit of electricity consumed.
• Shoulder seasons: Spring and autumn in Sydney typically require minimal system use, which keeps the annual average manageable.

Tips to reduce ducted AC running costs

• Use zoning properly. Only run the zones that are actually occupied. Consistently running zones in empty rooms is the most common source of unnecessary spend.
• Set a sensible temperature. Every degree lower in summer (or higher in winter) adds to the compressor load. 24–26 degrees in summer and 20–22 degrees in winter are comfortable ranges for most Sydney households.
• Use scheduling. If your system has a timer or smart controller, pre-cool or pre-heat before peak use rather than running hard to recover from extreme temperatures.
• Keep filters clean. A dirty return air filter chokes the system’s airflow. Most ducted systems have a filter that can be removed and washed; check your manual for its location and recommended cleaning interval.
• Service regularly. A system operating at degraded efficiency due to dirty coils or low refrigerant levels costs more to run.

Gas ducted heating is a common alternative in Sydney, particularly in older homes where a gas system was installed before reverse cycle became affordable at a whole-home scale. If you’re weighing up the two, here’s an honest comparison.

The practical conclusion for most Sydney households: if you need both cooling and heating, a reverse cycle ducted system is the right choice. Gas ducted heating only makes sense if you already have a gas system in good condition and your cooling needs are minimal or handled separately.

Thinking of replacing your existing gas ducted system? Get in touch for a site assessment and we’ll compare the full cost picture over 10 years rather than just upfront.

Paragon Air installs and services ducted air conditioning systems across Greater Sydney.

• Inner West
• Hills District
• Canterbury-Bankstown
• Western Suburbs
• North Shore
• Eastern Suburbs
• St George
• Sutherland Shire
• Northern Beaches
• Northern Suburbs
• Sydney CBD
• Macarthur

Check out the areas we service for the complete list of suburbs. If your suburb isn’t listed, call us on 1300 507 892 and we’ll confirm coverage.

How long does ducted air conditioning last?

A well-maintained ducted air conditioning system typically lasts 15 to 20 years. Lifespan depends on the quality of the original installation, how often the system is serviced, and how hard it runs. Systems that are regularly serviced and correctly sized for the home consistently outlast those that aren’t.

Can ducted air conditioning heat as well as cool?

Yes. Most ducted systems are reverse cycle, meaning the same unit cools your home in summer and heats it in winter. Reverse-cycle ducted systems are the most common type installed across Sydney, and most systems Paragon supplies are reverse cycle unless otherwise specified.

Do I need council approval to install ducted air conditioning?

In most residential cases in NSW, ducted air conditioning installation does not require council development approval. It is typically treated as exempt development under the State Environmental Planning Policy, provided the outdoor unit placement meets certain noise and setback requirements. You should check your local council’s requirements and any strata by-laws if applicable. Paragon can advise on what’s involved during the site assessment.

Can I add zones to an existing ducted system?

Sometimes, but it depends on what’s already installed. If your existing system uses a compatible zone controller and the ductwork can support additional dampers, adding zones is possible. Older systems or those installed with non-zoning-compatible components may not support it, or may require a controller upgrade. The easiest way to find out is to book a service visit and we’ll assess what’s in place.

Is ducted air conditioning noisy?

Ducted systems are among the quietest options for whole-home air conditioning. The compressor sits in the roof cavity or outside the building, so there’s no fan noise inside the living areas. Airflow through well-designed ductwork is quiet. If you do hear noise from a ducted system, it usually indicates an issue rather than normal operation.

How often should I service my ducted air conditioning?

Paragon recommends servicing your ducted system once a year. An annual service keeps filters clean, checks that all zone dampers are operating correctly, and catches small issues before they become expensive repairs. In homes where the system runs heavily during summer, a pre-season service in spring is worth scheduling before the peak cooling period.

What happens if a zone stops working?

A zone that stops responding is usually caused by a faulty motorised damper, a wiring fault in the zone controller, or a controller board issue. In most cases it’s a straightforward repair. Until it’s fixed, you can continue using other zones normally. Call us and we’ll diagnose it properly.

Can ducted air conditioning be installed without a roof cavity?

Not in the conventional sense. Standard ducted systems require a roof cavity to house the indoor unit and run ductwork to each zone. Homes with flat roofs, skillion roofs, or concrete slab ceilings typically can’t accommodate a ducted system. In those cases, alternatives like cassette air conditioning or split systems are usually the right solution. A site inspection will confirm what’s possible for your specific property.

Is ducted air conditioning suitable for a 2-storey home?

Yes, and in many ways a 2-storey home benefits more from a ducted system than a single-storey. The ability to zone upstairs and downstairs separately means you’re only conditioning the floor that’s in use, which in a typical household is a real efficiency gain. Ductwork routing across two floors is more involved than a single-storey install, and access to the upper-floor ceiling space needs to be assessed, but 2-storey homes are a common and very workable application for ducted systems.