Keep your indoor air clean and free from dust and pollutants with the Blueair Blue Pure 311i Max air purifier. Ideal for medium sized spaces, it can purify up to 387 square feet in 12.5 minutes and up to 929 square feet in 30 minutes. Powered by proprietary HEPASilent dual filtration technology, this air purifier can clean the air 83% faster while reducing noise levels by 50%.