Ducted air conditioning is a major investment, and plenty of Brisbane homes now have systems that are 12 to 20 years old. If yours is struggling, noisy or costing more to run each summer, the question is whether to keep repairing it or replace it. This guide covers the signs, the cost ranges and what a changeover actually involves.
Planning a new air conditioner? Split systems supplied and installed from $1,500 inc GST by our licensed electrical and refrigeration team. Get a fixed-price quote or call 0400 775 002.
Signs it is time to replace rather than repair
- Age: most ducted systems last 12 to 15 years in Brisbane’s humid climate, with coastal homes often shorter
- Refrigerant type: older R22 systems are expensive to service because the gas is no longer available for new supply
- Repeat repairs: two or more call-outs in a year, or a compressor fault, usually means it is near the end of its life
- Rising power bills: an old fixed-speed unit can use far more electricity than a modern inverter system
- Uneven cooling: rooms that never get comfortable, even when the filters and vents are clean
- Noise and vibration: failing fan motors and worn bearings often show up as rattling or humming
If the unit is not cooling at all, check the basics in our guide on ducted system faults before deciding.
What does replacement cost?
Pricing depends on system size, brand, number of zones and how much of the existing ductwork can be reused. As a rough guide for a typical Brisbane family home:
- Replacement of an 8 to 10 kW system using existing ducts: from around $7,000 to $11,000 installed
- 14 to 16 kW systems for larger homes: from around $10,000 to $16,000 installed
- New or modified ductwork, extra zones and switchboard work: priced on top after inspection
These ranges are indicative only. A site visit is the only way to give a firm figure, because the condition of the ducts, the roof access and the electrical supply all affect the price.
Can the existing ductwork be reused?
Often yes, but it needs checking. Ducts that are crushed, disconnected, leaking or poorly insulated waste a large share of the cooling you pay for. A modern system with old, damaged ducts will not perform as designed. We inspect the roof space, test airflow and recommend repairs or partial replacement where required. For more on how zones improve comfort and running cost, see our guide to ducted air conditioning zoning.
Choosing the right size
Bigger is not better. An oversized unit short-cycles, removes less humidity and wears out sooner. The correct capacity depends on floor area, ceiling height, insulation, window orientation and how the home is used. Our article on choosing the right air conditioner size explains the factors involved. If you are weighing ducted against other options, read split versus ducted systems.
Electrical considerations
Older ducted systems frequently sit on tired circuits. A replacement may need a new dedicated circuit, an upgraded isolator or a switchboard with spare capacity, and larger systems can require three-phase supply. Because we are both a licensed electrician and an air conditioning contractor, this is handled in one job rather than two trades pointing at each other. See three-phase power upgrades if your home may need one.
What the changeover involves
- Site inspection of the unit, ducts, switchboard and roof access
- Written quote with system options, including running-cost differences
- Recovery of the old refrigerant by an ARCtick licensed technician
- Removal of the old indoor and outdoor units
- Installation of the new system, controller and any duct repairs
- Commissioning, airflow balancing and handover
Most residential changeovers take one to two days, so you are without cooling for a short period only. Booking in autumn or spring avoids the summer rush and long waits.
Is the saving worth it?
It depends on how hard the system works. Households that run ducted cooling daily from October to April see the biggest difference, while homes that use it only on the hottest days take longer to recover the cost.
A modern inverter system can use significantly less electricity than a 15-year-old fixed-speed unit, and many homeowners notice quieter operation and more even temperatures as well. Over a 10-year horizon the lower running cost offsets part of the purchase price.
Get a ducted replacement quote
Integrated Trade Services designs, installs and replaces ducted systems across Brisbane and Moreton Bay. Request a free site inspection and quote, or view our air conditioning services.
Planning a new or replacement system? See our air conditioning installation page for typical prices, or our full range of air conditioning services.