Sizing matters more than brand
An undersized unit runs flat out and never quite gets there. An oversized one is worse — it drops the temperature quickly, shuts off before it has pulled any moisture out of the air, and leaves the room cold and damp. Taking humidity out is half the job, not a side effect of it. We size off room volume, glazing, orientation and insulation rather than floor area alone.
The cheapest quote usually leaves something out
Compare what is actually included, not just the total. Brackets, condensate drainage, cable and conduit, penetrations sealed properly, make-good on the wall, commissioning, and the warranty registered in your name. A quote that is a few hundred dollars cheaper because it stops at the unit itself is not cheaper.
Where the outdoor unit goes is not just about looks
Put it in a hot, unventilated corner and it works harder for less output. Put it under a bedroom window — yours or the neighbour’s — and you will hear about it. Noise limits apply at the boundary, and body corporate rules apply on top of that in units and townhouses.
Older switchboards often need work first
A ducted system, or a couple of splits added to a house built before the 1990s, can exceed what the existing board and supply will carry. Because we are electricians as well as installers, that is a line on the same quote and the same visit, not a surprise on install day.