Best Portable Air Conditioners

Roughly 20 BTU per square foot: about 8,000 BTU for up to 350 sq ft, ~10,000 BTU for 350–450 sq ft, 12,000 BTU for 450–550 sq ft, and 14,000 BTU for 550–700 sq ft. Add about 10% for sunny rooms or kitchens. Note that portable ACs are commonly advertised in ASHRAE BTU but rated for room size by the lower DOE/SACC figure, so check both numbers.

Dual-hose units (the Midea Duo, Whynter, and Hisense here) cool faster and more efficiently because they don't pull already-cooled room air out the exhaust, but they're typically louder and pricier. Single-hose units are simpler and cheaper and are fine for smaller rooms. For a large or sun-exposed space, dual-hose is the better choice.

No — for the same BTU, a window unit cools more efficiently and quietly. Portables win only when you can't install a window unit (renters, casement or sliding windows, four-season climates) or when you need to roll the unit between rooms. If a window unit is an option, it's usually the better value.

It depends. Many modern units (like Dreo's self-evaporation models) exhaust most condensate through the hose and rarely need draining in normal humidity. Dual-hose units and very humid climates produce more water and need periodic draining. All portable ACs should be fully drained before off-season storage to prevent mold.

Inverter models run quietest because the compressor modulates instead of cycling fully on and off — the LG dual-inverter, the Frigidaire Gallery inverter, and De'Longhi's Silent-tuned Pinguino are the quiet picks here. Even the best portables hover around 50–55 dB on high, which is louder than a comparable window unit.

No. A portable AC is a refrigeration unit that actually lowers the temperature and dehumidifies, and it vents hot air out a window. An evaporative cooler blows air over water and only cools effectively in dry climates — it adds humidity and doesn't vent. This list covers true compressor-based portable ACs only.