¹ 2020 ASHRAE Handbook—HVACSustems and Equioment, Chapter 22, Humiditiers.
² Studies have shown that exposure to very low indoor humidity create discomfort in the dry nasal cavity and reduce the mucociliary clearance time. This is strongly age dependent (i.e., the elderly are more vulnerable than young subjects).
³ Very dry climate may increase evaporation of the tear film. Studies have shown that dry eye discomfort is higher and more frequent at very low relative humidity.
⁴ Studies suggest that the best relative humidity for sleeping is between 40% and 60%.
⁵ In dry environment, studies have shown that static charge accumulation is easier on surfaces than humid condition.
⁶ The American Academy of Dermatology recommends, amongst other things, using a humidifier helps to relieve dry skin.
⁷ The CDC recommends, amongst other things, using a clean humidifier helps to relieve sore throat.
⁸ Studies for specific virus strains performed in controlled environment have shown low infectivity at mid humidity range.
⁹ Compared to standard ultrasonic humiditiers that do not contain additional technology to reduce bacteria-spreading, tested by independent lab.
¹⁰ Only applicable for specific models.
¹¹ Philips guarantees performance of purifier only with original replacement parts.