If you want to cool a big space, the Zafro handles more square footage than anything else on this list. It’s rated for rooms up to 600 square feet, thanks to its 16,000 BTU (12,000 SACC) dual-hose system. The efficient inverter compressor ramps output up and down instead of cycling on and off, but you’ll barely hear it—this unit runs at 38 decibels on its quietest setting.