"Portable air conditioner" covers everything from a $50 desktop water cooler to a $1,500 battery-powered heat pump. Buying the wrong type is the most expensive mistake in this category, so here's the field guide.
Cooling-only portables
The classic: refrigerated cooling plus fan and dehumidify modes, vented through a window duct. Cheapest per kilowatt and all most Australians need. If your winters are mild or otherwise covered, buy this and save.
Reverse-cycle portables
The same machine with a valve that runs the refrigeration cycle backwards in winter, pumping heat into the room instead of out. Heat-pump warmth costs roughly a third as much per unit of heat as a plug-in electric heater, so in a genuine four-season climate the price premium usually repays itself within a couple of winters. See the reverse-cycle range.
Single-hose portables
One duct expels hot air; the air cooling the compressor is drawn from the room itself, creating slight negative pressure that pulls warm outside air back in through gaps. Standard, cheaper, and perfectly fine for bedrooms and offices.
Dual-hose portables
A second duct draws outside air for the compressor, eliminating the negative-pressure problem. Meaningfully more efficient in large rooms and extreme heat — worth seeking out for living areas, though the range available in Australia is smaller.
Evaporative "portable air conditioners"
Not air conditioners at all: they cool by evaporating water, which works beautifully in Perth's dry heat and barely at all in Brisbane humidity. No exhaust hose is the giveaway. Great machines in the right climate — read evaporative vs refrigerated before choosing this path.
Battery and 12V portables
The new category: compact heat pumps like the EcoFlow WAVE series that run off battery packs for caravans, boats and camping. Expensive per kilowatt, magic where mains power isn't an option. See the camping range.
Which type is right?
Most buyers: cooling-only, single hose, sized to the room. Cold-winter regions: reverse cycle. Big rooms and scorcher climates: dual hose or simply more kilowatts. Dry inland climates: consider evaporative. Off-grid: battery. Then work through the choosing guide to nail the size.