Residential / General electrical
Split system air conditioning
Comfort where you need it. We help plan split system air conditioning around room size, use, placement and electrical supply.
Local electricians · Clear advice · Ongoing support
Sizing the unit
An undersized unit runs flat out and never quite gets there. An oversized one cools the air quickly, shuts off before it has removed the humidity, and leaves the room cold and clammy. In a subtropical climate humidity control matters as much as temperature, so oversizing is a real mistake rather than a safe margin.
Sizing depends on floor area, ceiling height, how much glass the room has and which way it faces, insulation, and whether the space is open to the rest of the house. West-facing glass in Queensland makes a large difference. We work it out from the room rather than from a rule of thumb.
Placement and pipe runs
Back-to-back
The indoor unit on an external wall with the outdoor unit directly behind it. The shortest pipe run, the cheapest install and the best performance.
Long run
Where the indoor unit has to sit away from an external wall. Entirely workable, but it needs more refrigerant pipe and careful routing, and it costs more.
Outdoor unit position
Needs airflow, shade where possible, and to be away from bedroom windows and the neighbours. A unit baking in afternoon sun works harder for the same result.
The electrical side
This is where being electricians rather than only air conditioning installers matters. A split system needs its own dedicated circuit with correctly rated cable and an isolator at the outdoor unit. It cannot share a general power circuit, and adding one to a board with no spare ways means the board comes first. See power points and circuits and switchboard upgrades.
Running it on solar
Air conditioning is a large daytime load, which makes it one of the best things to run on your own solar. If the house is occupied during the day, cooling through the middle of the day costs very little when the array is producing. Pair it with battery storage and you can carry that into the evening peak as well.
Pre-cool while the sun is up. If you have solar, running the air conditioner hard from late morning and easing off in the evening uses power you generated rather than power you buy. It is the cheapest comfort available.
Good to know
Your questions, answered.
What size unit do I need?
It depends on the room, not just its floor area. Glass, orientation, ceiling height and whether the space is open-plan all change the answer. We size it on site.
Can you install a unit I have already bought?
Usually yes, provided it is suitable for the room and the install position. We will tell you before we start if we think it is the wrong capacity.
Do I need a dedicated circuit?
Yes. Split systems require their own correctly rated circuit and an isolator at the outdoor unit.
Can you install more than one at a time?
Yes, and doing several in one visit usually works out better because the electrical work and access are shared. For whole-home cooling, see ducted air conditioning.
Let’s talk about your project.
Tell us your suburb, priorities and the work you have in mind. We’ll help you take the next step.