Derating

Derating is the capacity an air conditioner loses as outdoor temperature rises, a unit rated at 7kW may deliver far less at 43°C, exactly when you need it most.

Ratings are measured at 35°C outdoors. On a western Sydney or Penrith January day pushing 45°C, budget units can lose 20–30% of rated capacity while premium units hold most of theirs. If you live somewhere with real heat, ask installers what the unit delivers at 43°C, it separates the tiers faster than any brochure.