The world is getting warmer. And the weather is getting weirder. Air conditioning isn't the answer, but it does help: Extreme heat is exhausting, and it ages you faster than smoking or drinking. The best window air conditioners—like our top pick, Midea's 8,000 BTU U-Shaped Smart Inverter Window Air Conditioner ($400)—offer sweet relief. This Midea model also has a smart design that still lets you open your window. Like our other favorite window and portable cooling units, the Midea is among the most energy-efficient on the market, and uses newfangled coolants that don't deplete the ozone like the more damaging ones of yore. Heat pumps are even more efficient, and minisplits like the Della Optima Series 12,000 BTU 23 SEER2 ($970) are becoming increasingly accessible although they require expensive installation. We've also included the best models for those on a tight budget, such a surprisingly quiet small-room 5,000 BTU air conditioner from GE for a mere $164. But note that budget models generally aren't as efficient, so saving on upfront cost can lead to higher energy bills over time. Be sure to check out our other air quality guides, including Best Air Purifiers, Best Indoor Air Quality Monitors, and Best Fans. Updated May 2026: We've added the Della Optima Series 12,000 BTU 23 SEER2 as a heat pump option, and the newly updated Zafro dual-hose portable smart inverter. We've also removed discontinued models and brands such as July, streamlined our top picks, and updated links and pricing throughout. Surprise: A window air conditioner that actually lets you open the window. Midea’s U-shaped AC comes with a bracket that balances the unit’s weight by leaning against the exterior wall of your home, so you can open the window without worrying your AC will fall out. The big notch between the front and back also lets you pull down your window deep into the unit, leading to less of an air gap and better efficiency. (It's also nice for soundproofing, noted WIRED senior