Blueair Air Purifier, Blue Pure 311 Auto, up to 1862 sq ft

This review covers the 211+, 311 Auto, and 411. My Temtop M10 air quality monitor independently verified that the 411 and 211+ worked well during the recent wildfires. While necessary when air quality is bad, the 411 at lowest setting uses too much energy (30W as confirmed by a power monitor) for everyday use. The 211+ required the medium and noisy setting to keep my large main bedroom below 25 AQI (versus 50+) while sleeping. Although received too late for the wildfires, the 311 seems like a good compromise between capacity, power consumption, and noise. It *is* (barely) audible at lowest speed, unlike the is-it-really-on 211+, but many other household sounds will drown it out. As noted by other users of Blue Air products, there is an initial slight burnt-air odor from activated charcoal filter (as was the case with the 411). If one's room is small enough, I highly recommend the 211+. Being too quiet to hear is a huge overlooked advantage. The one caveat is that a quiet but noticeable rattle developed after a couple months of continuous operation.