Ducted air conditioning is the most expensive AC type to install and the most ignored to maintain. Most Brisbane ducted systems get cleaned approximately never — until they're blowing musty air or the power bill doubles. Here's the actual maintenance schedule that keeps a ducted system running for 15+ years without surprises, written by people who clean them every day.

What "maintenance" actually means for ducted

Ducted aircon has way more parts than a split system, and most are hidden in your ceiling cavity. A real maintenance job touches:

Return air filter — the big grille usually in your hallway ceiling. Pulls ALL your home's air through it. Forgotten in 90% of homes we visit.
Indoor coil (evaporator) — the cold part where humidity condenses. Mould factory if neglected.
Drain pan + line — clogs in 12-18 months in Brisbane's humidity. Causes ceiling leaks.
Ceiling vents (outlets) — what your guests see. If they're black around the edges, they're filthy.
Outdoor condenser — gets coated in dust, grass clippings, pollen.
Ductwork itself — flexible insulated tubes in your ceiling. Usually doesn't need cleaning unless visibly damaged.

The realistic maintenance schedule

Not the manufacturer's lawyer-written schedule. The actual one based on what we see in Brisbane homes.

Every 3 months (DIY, free)

Pull the return air filter, vacuum it, wash if it's a washable type
Check outdoor condenser for leaves / grass clippings — brush them off
Walk around inside and look at ceiling vents — black edges = book a clean

Total time: 10 minutes. Save: hundreds in lost efficiency.

Annually (professional)

Full coil chemical wash (not a wipe — the coil itself)
Drain pan + line flush with biocide
All ceiling vents pulled, cleaned, sanitised, reinstalled
Outdoor condenser washed
Performance check — actual temp drop across the coil

Most Brisbane homes: $299-$399 single-storey, $399-$499 double-storey.

Every 5 years (professional, optional)

Antibacterial fog of the full ductwork — kills accumulated mould spores
Refrigerant pressure check (ARC-licensed tech only)
Damper inspection (the things that direct airflow to specific rooms)

Why Brisbane is harder on ducted than other cities

Brisbane runs at 70-90% humidity for half the year. Your ducted system pulls 20-40 litres of water out of the air per week during summer. That water has to drain. When it doesn't drain properly:

Drain pan overflow → ceiling stain in the room above
Mould grows in the drain line → musty smell every time AC runs
Mould spores blow into your home through the vents → allergy + asthma flare-ups
Coil corrosion → premature compressor failure ($3,000+ replacement)

The "every 12 months" rule that works in Sydney is too thin for Brisbane. We see homes where the owner has never cleaned the ducted system in 8 years. The coil looks like the inside of a mouldy shower.

5 signs your ducted is overdue

Musty smell when the AC first turns on — mould in the coil or drain
Power bill jumped with no change in usage — dirty system working harder
Black edges on the ceiling vents — dust building up + spreading
Allergy / asthma flare-ups when AC runs — biological contamination
One room not cooling as well as others — damper issue or vent blockage

What you should NOT pay extra for

Ducted aircon is a complicated product and dodgy contractors use that to upsell. Avoid:

"Duct cleaning" as a separate $500 service. The actual ducts (flex tubes) rarely need cleaning unless visibly damaged. Most "duct cleaning" companies are upselling something that doesn't fix anything.
"Annual service plans" that include monthly inspections. Once a year is enough for cleaning. Monthly is sales theatre.
Refrigerant top-ups as routine maintenance. Refrigerant doesn't get "used up" — if you're low, you have a leak that needs fixing, not topping up.
UV light installations in the ductwork. Marginal evidence they help, marketed hard. Save the $400 for a proper clean.

What we actually do (so you know what to expect)

Our ducted clean takes 60-120 minutes depending on house size. Here's the order of operations:

Pull the return air filter, replace if needed
Cover the coil access opening with protective sheeting
Chemical wash the indoor coil — biocide solution, rinse with clean water
Flush the drain pan + drain line with biocide
Remove each ceiling vent, wash it, sanitise, reinstall
Wash the outdoor condenser fins
Test cooling performance — actual temp drop measured at the central vent
Photo report sent to you with before/after of the coil + drain

If we find something that needs more than a clean (gas leak, dead capacitor, failed damper) we tell you straight and don't pretend we can fix it ourselves. We're cleaners, not repair people. That's the deal.

Book a ducted clean

Fixed price ($299 single-storey / $399+ larger). 60-second online booking. We'll send photos of the before/after coil so you actually see what we did.

See Full Ducted Service

Bottom line

If you have ducted aircon in Brisbane and you can't remember the last clean, it's overdue. A real clean once a year prevents 90% of the expensive problems (coil corrosion, mould issues, premature compressor failure). The DIY filter check every 3 months is free and takes 5 minutes. Everything else, leave to a pro who cleans these every day.