It turns red at the height of intake of bad smells, then gradually turns orange, then back to blue, to show you that it is working to rid the air of any pollutants.
Are Blue air purifiers good?
With a combination of both mechanical and electrostatic filtration, the HEPASilent technology can trap even the tiny 0.1 microns airborne particles of pollutants, with an efficiency rate of 99.97%. It is safe to say that the air filtration technology of Blueair is one of the best at the moment.
The Air Quality Indicator tests the air and displays a blue, orange or red light depending on how clean or how polluted the air is. You can also manually change it.
Are winix air purifiers good?
The NK105 adds WiFi and the Winix Smart app. Pros: Very good filtering of 99.97% of pollutants plus odors, VOCs and smoke. WiFi makes it convenient to monitor and control the purifier from anywhere. Cons: The filter is expensive, but most True HEPA filters are.