In this section
- CalculatorRoom size calculatorHow many BTU do you need to cool a room? Based on ENERGY STAR's room air conditioner sizing chart, adjusted for sun, people and kitchens.
- GuideWindow vs portableWhy portable ACs cool less per watt than window units, what the SACC rating means, and when a portable is still the right choice.
Run it less
- Fans. DOE says a ceiling fan lets you raise the thermostat about 4°F with no loss of comfort. Fans cool people, not rooms, so turn them off when you leave.
- Block the sun. Close blinds and curtains on sunny windows in the afternoon.
- Dry the air. In humid climates, dry air feels cooler, so you can set the AC a degree or two higher.
Window units
Inverter window ACs, like Midea’s U-shaped unit and LG’s Dual Inverter line, slow their compressor down instead of cycling on and off. That uses less power at part load and is much quieter. Look for ENERGY STAR and a high CEER number on the EnergyGuide label.
Size it to the room. Too small runs constantly; too big cools fast but leaves the room clammy. Room size calculator
Portable units cost more to run
A portable AC sits inside the room, so its own heat and the warm air it pulls in through gaps count against it. Window vs portable
Picks
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Midea U Inverter window air conditioner
Quietest efficient window AC
- U shape: window closes between the halves
- Inverter compressor
- ENERGY STAR
Inverter units run slower instead of cycling on and off, which uses less power and is quieter.
Watch for: Heavier than a basic unit; follow the bracket instructions.
LG Dual Inverter window AC
Second inverter option
- Inverter compressor
- ENERGY STAR models
A wide range of sizes when the Midea is out of stock.
Watch for: Check the CEER rating; it varies by size.
Midea Duo portable AC
Windows that can't take a window unit
- Hose-in-hose design
- Inverter compressor
Most portables waste energy pulling warm air in through the walls. The Duo's design limits that.
Watch for: A window unit of the same size still cools more for less power.
Vornado 630 air circulator
Raising the thermostat a few degrees
- Moves air across the whole room
Moving air feels cooler, so you can set the AC higher.
Watch for: Fans cool people, not rooms; turn it off when you leave.
Midea Cube dehumidifier
Damp basements and sticky summers
- Stackable tank
- Pump-out option on some sizes
Dry air feels cooler, so the AC runs less in humid climates.
Watch for: Size it in pints per day to the space.