Everything You Need to Know About Ducted Air Conditioning Installation in Brisbane

How ducted air conditioning actually works

Ducted AC delivers cooling and heating through ceiling vents in every room from a single indoor unit hidden in the ceiling cavity. Air is pulled through a central return-air grille (usually in a hallway), passed over the cooled or heated evaporator coil, then pushed back out through flexible ducts to each supply outlet. An outdoor compressor pumps refrigerant in a loop to provide the cooling or heating effect.

Zoning controls let you cool only the rooms you’re using. A typical 4-zone system has dampers in the ductwork that open and close based on the wall controller settings — so the bedrooms can be 22°C overnight while the rest of the house is off.

Brisbane ducted install pricing (2026)

Prices fully installed inc GST with inverter outdoor unit, ductwork to spec, zone motors, return-air grille, supply outlets, wall controller. Final price depends on home, brand and add-ons.

Capacity sizing — the make-or-break decision

Wrong capacity = wrong system. Too small struggles, runs flat-out, fails early. Too big short-cycles, fails to dehumidify, wastes power. Brisbane sizing rules of thumb (refine with on-site Manual J calc):

• 3-bed Brisbane home (130–160 m²): 12–14kW
• 4-bed (180–220 m²): 14–18kW
• 5-bed+ (250+ m²): 18–24kW
• Uninsulated Queenslander: +20% over modern equivalent
• West-facing main living: +1–2kW
• Cathedral / vaulted ceilings: +15–25% (more air volume)

Insist on an on-site sizing visit. Phone quotes are guesses and undersizing is the #1 cause of long-term regret.

Zoning — how many zones?

• Minimum 4: Open-plan living / master bedroom / kids’ bedrooms grouped / study
• Comfortable 5–6: Living split from kitchen, bedrooms individually
• Premium 7+: Every bedroom separately, formal lounge, theatre, study, alfresco-adjacent

Each zone adds $400–$700 to the install. Worth it for any room used independently.

Ceiling cavity check

Ducted indoor units need clearance above the ceiling. Standard minimum: 450mm cavity. Brisbane reality:

• Modern slab (post-2000): 500–800mm. Plenty.
• Highset Queenslander: 400–600mm. Usually workable.
• Lowset 60–70s brick: often 280–400mm. Bulkhead drop needed.
• Cathedral / vaulted: No cavity. Ducted impossible — consider multi-head splits instead.

Top brands for Brisbane ducted

• Daikin inverter — best efficiency, best parts (24hr), strongest resale recognition
• Braemar — Australian-made, refrigerated-only OR combo with gas heating
• Mitsubishi Electric — premium-feature option, M-NET diagnostics
• Fujitsu — mid-tier value

Full comparison: Braemar vs Daikin ducted.

Install process — what happens

1. Free on-site assessment — sizing calc, ceiling cavity check, electrical capacity, outdoor unit location
2. Written quote 24 hours later — itemised, GST-inclusive, 30 days valid
3. Booking — 2–4 weeks lead time in cool season, 6–10 weeks in peak summer
4. Day 1: Indoor unit mounted in cavity. Ductwork run to each zone. Return-air grille installed.
5. Day 2: Supply outlets cut into ceiling. Refrigerant pipework run to outdoor unit location.
6. Day 3: Outdoor unit installed. Electrical commissioned. System gas-charged, pressure-tested, run-tested.
7. Walk-through — controller operation, zoning use, basic filter maintenance
8. Warranty registered — manufacturer 5-yr + AH Aircon 10-yr workmanship

7 most common ducted mistakes

1. Undersized capacity — struggles in peak summer, fails early
2. Too few zones — you end up cooling rooms you don’t use
3. Non-inverter system — $600–$800/yr higher running cost vs inverter
4. Cheap installer cutting corners — thin pipe insulation, undersized return-air grille, crushed ducts
5. Skipping on-site assessment — phone quotes miss critical site issues
6. Booking too late — January install = 6 week wait
7. Skipping the bulkhead disclosure — learn cavity depth at quote, not install day

See our pre-install checklist: 7 things to know before ducted install.

Running cost (Brisbane, typical 16kW inverter ducted)

• Cooling season (6 months): $1,200–$1,600/yr running 3–5 zones
• Heating season (3 months): $200–$400/yr
• Annual total: $1,400–$2,000/yr

Non-inverter equivalent: $1,800–$2,400/yr. Inverter pays back the $1,500–$2,500 upfront premium in 2–3 years.

Finance options

• Brighte — 0% interest 12–24 months on residential AC, on approval
• Humm — 0% interest up to 24 months on approval
• Bank personal loan — longer terms (3–5 yrs), monthly $200–$400

Common questions

How much does ducted air conditioning cost in Brisbane?

Most Brisbane 4-bedroom homes pay $11,000–$17,000 fully installed for quality inverter system. 5-bedroom from $15,800. Bulkhead drops add $1,500–$3,000.

How long does ducted install take in Brisbane?

2–3 days for residential retrofit. 1–2 days for new builds where cavity is prepped.

What size ducted do I need?

3-bed: 12–14kW. 4-bed: 14–18kW. 5+: 18–24kW. Refined with on-site Manual J sizing calc.

When should I book to be running by Christmas?

By early October. After October lead times stretch toward 6–10 weeks for peak summer.

Inverter or non-inverter?

Inverter, always. Pays back the $1,500–$2,500 upfront premium in 2–3 years on running cost.

Can ducted go in any Brisbane home?

Most. Cathedral/vaulted ceilings can’t take ducted — multi-head splits are the alternative. Some lowset 60s/70s brick homes need a bulkhead drop.

Is finance available?

Yes — Brighte and Humm both offer 0% interest 12–24 months on approval.

AH Air Conditioning · 63 Britannia Ave, Morningside QLD 4170 · ARCtick licensed · 20+ years across Brisbane.