You have received a quote for your new split system installation, but the line item for “installation” is vague, leading you to worry about hidden costs when the technicians arrive. A comprehensive quote must itemize the circuit amperage and breaker rating, conduit run length and type, structural mounting reinforcement, refrigerant line set metres, and the condensate drainage connection point. Without these specifics in your split system installation checklist, you risk significant cost overruns once work begins.
Does your quote specify circuit amperage?
Every inverter requires a dedicated circuit with a specific amperage. Your quote must list the required breaker rating, typically 16A or 20A depending on the unit size. This rating dictates whether your existing switchboard and wiring have enough capacity to handle the new load without tripping or overheating. If your home lacks this capacity, the quote must explicitly state the cost of a switchboard upgrade or installing a new dedicated circuit from the panel to the unit.
When wiring needs upgrading
If your home has older aluminium wiring or lacks a dedicated outlet for the AC, the quote must cover running new cabling from the switchboard. This often involves drilling through masonry or timber framing. Ensure the quote specifies the distance from the breaker to the outdoor unit location. Running 30 metres of cable costs significantly more than 10 metres, and skipping this line item is a primary cause of variation claims.
Conduit run length and type details
Brisbane weather requires protection for external refrigerant pipes and power cables. Your quote should specify the exact conduit run length and whether it is internal trunking or external conduit. UV exposure can degrade standard pipe insulation quickly in this subtropical climate, so the quote must confirm if UV-rated conduit or a weatherproof IP-rated isolator is included. Cheaper quotes often assume a short run, such as 3 metres. If your outdoor unit is further from the indoor wall, you will pay a steep variation rate per metre.
Internal versus external conduit rules
Internal trunking looks cleaner but may require cutting through plaster or gyprock, while external conduit is faster to install but less aesthetic. The decision rule depends on the route length and structural impact: if the run exceeds 10 metres or requires cutting into load-bearing timber, external conduit is preferred. Your quote should clearly state which method is used and the cost if you request a change.
Structural mounting points for older homes
For older Brisbane homes, the quote needs a defined scope for structural mounting points. It must detail whether the existing wall substrate requires reinforcement. A common mistake is fixing brackets directly into brickwork that has crumbling mortar or into timber stud walls that lack solid backing. This can lead to the outdoor unit pulling away from the wall during high winds.
When reinforcement is triggered
Reinforcement is triggered if mortar joints fail a pull test, stud spacing exceeds 600mm, or the home has fibro cladding. The quote must list the specific remedy, such as chemical anchors for masonry, timber blocking for cavities, or a slab bracket for concrete pads. If the quote assumes a standard masonry wall but your home has fibro cladding, the mounting strategy changes and must be priced upfront.
Refrigerant line set length included
The scope must clearly delineate the length and type of refrigerant line sets included. Most standard quotes include 3 to 5 metres of piping. If your outdoor unit is mounted on a rear wall or far from the indoor evaporator, you will need extra piping. Extra piping is a common unquoted variation item that adds to the final bill.
Maximum run and height rules
The quote must state the included metre allowance and the per-metre variation rate. It should also confirm the maximum pipe run and height differential the manufacturer allows. If your installation exceeds these limits, extra piping is priced upfront so you are not surprised by a higher final invoice.
Drainage connection decisions
A decision point must be established regarding the condensate drainage connection. The quote must specify the required fall and the connection point for the drain line. In Brisbane residential structures, water ingress can cause significant damage to internal linings.
Gravity fall versus pump options
Two options exist: gravity fall to an external wall or a condensate pump to a drain or floor sink. The quote must confirm a minimum fall rate of 1 in 50 for gravity drainage. If the indoor unit cannot drain by gravity, the quote must explicitly include the pump unit and any plumbing work required to move the water away safely. This allows the homeowner to choose before signing.
By providing a detailed, itemized scope of work covering electrical and structural prerequisites, Air Conditioning Expert Brisbane ensures the installation process is completed correctly the first time. We review your property conditions upfront to identify any electrical or structural challenges, preventing surprise costs when technicians arrive.
Sign-off before you agree
Before signing a quote, ask the installer to mark the quoted conduit route and pipe run on a simple sketch of your property. Verify that this sketch matches the line items for conduit length and drainage connection point. This concrete test ensures the document matches the physical reality of your home.
Send us your quote and we will return an itemized scope within 24 hours, flagging any missing breaker rating, conduit length, or drainage connection.
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