Blueair Blue Pure 511 Quickly purifies up to a 38 m2 space in 30 minutes on high. With a compact footprint and low noise level; as quiet as a whisper at 24 dB on low, its ideal for anywhere in the home and it removes at least 99.97% of airborne particles down to 0.1 microns. Blueair air purifiers are whisper-quiet and use less energy than a light bulb; without taking up too much space. Enjoy fresh air in a matter of minutes with the touch of a button.