A proper in-home AC assessment covers your room sizes, ceiling height, insulation, and existing ductwork so your installer knows exactly what your home needs before any work starts.
Most homeowners in Brisbane book an air conditioner installation and expect the installer to show up with a unit and a drill. But there’s a lot more involved if you want to install it right.
That’s exactly the approach a team like Gtallen takes from the start. They walk through your property first and check everything from your ceiling height to your insulation before recommending any system.
This article walks you through every part of the AC assessment checklist, what techs look for, why it affects your ducted air-conditioning cost, and what to expect on the day.
Read on, and you’ll know exactly what a proper assessment looks like before anyone sets foot in your home.
Your AC Assessment Checklist: What Techs Truly Look At
A tech runs through your home’s layout, heat sources, and existing air conditioning setup to build an accurate picture of what your system needs to do. Each part of the assessment feeds into the next. Miss one, and the whole calculation ends up wrong.
Now, let’s look at exactly what ends up on that checklist.
Room Size and Your Air Conditioning System’s Cooling Capacity
Techs measure every room to work out the cooling capacity your air conditioning system needs. The standard formula runs here at 0.15 to 0.16 kilowatts per square metre of floor space.
Basically, a tech who skips this measuring tape and eyeballs your room size is doing you no favours. Besides, open-plan living areas need individual calculations, because air behaves differently across large connected spaces.
Air Quality Checks and Ceiling Height
Ceiling height changes everything when you install an AC. For instance, a room with 3.2 metre ceilings holds significantly more air volume than one with a 2.7 metre ceiling, so the system needs more power to cool it down (these ceilings are not doing the same job, not even close).
Poor air quality from dust or mould spores also affects which reverse cycle system suits your home. That’s why the National Asthma Council Australia recommends filtering indoor air properly. Plus, techs factor this into their unit recommendations.
Window Size, Direction and Heat Load
Your window placement and glazing type can shift your heat load by several kilowatts. Yet most homeowners only realise this after installation.
But you should always be careful about the window size and heat load. And here’s the table to help you with that:
| Window Type | Heat Impact |
| Single-glazed, west-facing | Highest heat load, adds 2-3 kW |
| Double-glazed, west-facing | Moderate heat load |
| South-facing, any glazing | Lowest heat load |
Especially, west-facing windows in a Capalaba or Wynnum home can add 2 to 3 kilowatts to your total heat load, and that number adds up fast. Plus, single-glazed windows lose around three times more heat than double-glazed ones, based on figures from Your Home, Australian Government.
Insulation Condition and Roof Space Heat
Poor ceiling insulation lets the roof space heat push straight into your living areas. On top of that, degraded insulation batts perform well below their original rating, so age counts as much as thickness.
Drawing from our experience, roof spaces in Queensland homes can push internal temperatures up by 8 to 10 degrees on a 35-degree Brisbane summer day.
That’s why techs check both insulation thickness and condition because this directly affects how hard your ducted system needs to work to maintain a consistent temperature.
Ducted Air Conditioning Cost and What the Assessment Reveals
Most homeowners are surprised to find out that the assessment itself determines if their ducted air conditioning cost goes up or down.
Believe it or not, leaky ductwork is one of the most common things found during assessments in older Brisbane homes.
Once that’s established, the conversation shifts to your ductwork and zoning setup.
Ducted AC Installation Requirements for Your Home
Generally, techs check roof space access and ceiling cavity depth first. This confirms whether ducted air conditioning can go in without major structural changes to your home.
They even check your switchboard since the existing electrical capacity needs to handle the new air conditioning system load. Remember, your sparky can’t always just add a new circuit without looking at the whole board first (and that’s obviously not a minor fix either, since a switchboard costs a decent amount).
The distance between your indoor unit and outdoor unit also affects refrigerant line length. The longer the run, the higher the installation cost.
Ducted Air Conditioner Zoning and Ductwork Condition
Zoning splits your home into separate areas, so you can only cool the rooms you’re using, cutting running costs by up to 30%.
Besides, techs inspect existing ducts for leaks, damage, or blockages. During this inspection, they identify issues that restrict airflow, which can drive up your ducted air conditioning costs over time.
Based on our firsthand experience, at least one in three existing duct systems we inspect in homes around Redcliffe and North Lakes needs repair before a new unit goes in.
Sometimes, old or undersized ducts also need replacing before a new ducted air conditioner can deliver the cooling your home needs.
What Happens When Your Air Conditioning Unit Gets Inspected
The tech physically checks your outdoor compressor unit, filters, coils, and drainage lines to spot anything that is reducing performance or shortening the system’s life.
If these go unchecked, a dirty coil or blocked drain line will strangle your system’s output before you notice.
Precisely, the tech works through a few key areas:
- Refrigerant levels, rust, and physical damage on the outdoor unit
- Checks filters and electrical connections for buildup and efficiency loss
- Compressor and other components are put through performance testing
- Inspects clogged drainage lines to prevent a reduction in cooling performance
However, a compressor running under strain drives up energy costs and leads to costly repairs down the track. For this reason, the assessment flags whether your existing air conditioner is worth servicing or whether a full replacement is the wiser choice in the long term.
Air Conditioner Brands: Does Your Choice Change the Assessment?
Yes, your brand choice does affect parts of the assessment, though the core AC assessment checklist stays the same regardless of which unit you pick. Frankly, homeowners who skip the assessment end up paying for it twice.
Through our practical knowledge, brand selection genuinely shifts what the tech needs to assess, around outdoor unit clearance, zoning compatibility, and wall space for installation.
Take a look at how some of the most common brands stack up during an assessment:
| Brand | Zoning | Heating & Cooling | Solar Panels Compatible | Noise Level |
| Daikin Australia | Yes | Reverse cycle | Yes | Low |
| Fujitsu | Yes | Reverse cycle | Yes | Low |
| Mitsubishi | Yes | Reverse cycle | Yes | Very low |
| Panasonic | Yes | Reverse cycle | Yes | Low |
| LG | Yes | Reverse cycle | Yes | Low |
| Samsung | Limited | Reverse cycle | Yes | Moderate |
Each brand runs on a different control system and thermostat setup. Daikin, for instance, uses its own remote control and zoning interface, which the tech needs to factor into the electrical connections check. Meanwhile, split systems and multi-split configurations affect how the assessment reads your whole house cooling and heating range.
Once you get that wrong, you’re looking at a system that’s running constantly, never hitting temperature, and chewing through your electricity bill every single month.
Book Your In-Home Assessment Today
Skipping the assessment is one of the costliest mistakes a homeowner can make. Typically, homeowners who skip it end up paying for it twice, through poor cooling performance, higher running costs, and repairs that could have been avoided with a proper check-up.
A well-sized, energy-efficient ducted system installed in the right home delivers year-round comfort and keeps your energy costs down for years. But none of that happens without a thorough assessment first.
Here’s what a proper AC assessment sets you up for:
- A ducted air conditioning system sized to your actual whole-house cooling and heating needs
- Clean air flow, proper insulation checks, and efficient ducts throughout your entire home
- Lower running costs and fewer repairs over the life of your system
- An air conditioner that maintains a consistent temperature across every living area without overworking
Ready to get yours sorted? Gtallen runs in-home assessments across Australia, so you know exactly what your home needs before any installation begins.