Air conditioning installation: what to sort out before the installer arrives

What the job involves

For a split system, the installer mounts the indoor head, positions the outdoor compressor, runs refrigerant lines and drainage between them, makes the electrical connection and commissions the unit. The simplest version is back-to-back — compressor directly behind the indoor unit through one wall. Every metre of extra pipe run, every storey climbed and every roof-space detour adds labour.

Ducted reverse-cycle is a bigger project: one outdoor unit feeding ceiling vents throughout the house, with zoning so you're not cooling empty rooms. It involves roof-space work, a return-air point and a controller, and usually a day or two on site. It's the whole-home answer, and often better value than fitting splits in four or five rooms separately.

Sizing is where expertise shows. An undersized unit runs flat out and never quite gets there; an oversized one short-cycles and dehumidifies poorly. A good installer asks about room size, ceiling height, window orientation and insulation before naming a kilowatt figure.

What to expect on price

A small bedroom split installed back-to-back sits toward the lower end — typically under a couple of thousand, supplied and installed. Large living-area units with long pipe runs or dedicated circuits climb from there, and whole-home ducted systems run well into five figures. Indicative only; the estimate on this page adjusts for your unit count and install complexity.

Supply-and-install packages are usually better value than buying a unit yourself and finding someone to fit it — and they keep warranty responsibility in one place, which matters the day something fails.

Licences: this trade has two

Anyone handling refrigerant in Australia must hold an ARC (Australian Refrigeration Council) licence — ask to see it, and don't accept a shrug. The electrical side — dedicated circuits, switchboard work, hard-wiring — must be done by a licensed electrician. Many installers hold both or work in pairs; what matters is that both boxes are ticked on your job.

Beyond the paperwork, good installers talk about condensate drainage (where the water goes), outdoor unit clearance and noise, and whether your switchboard can take the load. If nobody has looked at your switchboard before quoting a big unit, the quote is incomplete.

Mistakes to avoid

Most air conditioning regrets are locked in before installation day. Slow down on these decisions.

• Letting price pick the unit size instead of the room — sizing errors annoy you every summer for a decade
• Not confirming the ARC licence and the electrical licence for the respective parts of the job
• Mounting the outdoor unit where its noise or hot exhaust hits a bedroom window or a neighbour's
• Ignoring the drain — poorly run condensate lines cause ceiling stains and mould
• Buying the unit online first, then discovering install-only quotes cost more and split the warranty
• Forgetting running costs — a cheaper, less efficient unit can give the saving back in power bills