The Blueair Blue Pure 311i Max Air Purifier is perfect for effortless air purifying. Its advanced HEPASilent technology cleans 387sq. ft. of living space in just 30 minutes, 929 sqft in 30 minutes, and 1800sqft in an hour; and is independently tested and verified for performance and safety. You can breathe easy knowing you get maximum air purifying efficiency with every breath. Plus, it's the Energy Star Most Efficient 2023.