These everyday decibel comparisons of ordinary sounds help to make sense of the ratings. Sound levels are usually usually measured in decibels, (abbreviated to "db").
One thing to remember about the decibel scale is that for every increase of ten decibels, the apparent loudness doubles.
I'm not going to go above 70 decibels in this chart, because that would be a loud and annoying level of sound. You won't find an air purifier or cleaner as loud as that on this site.
Some air cleaners and air purifiers are described a being silent. this means that they don't use a fan to push a volume of air through, and can't possibly be effective.
Distance from the source of the sound reduces the apparent noise. For that reason, in some of the comparisons below, a distance is given. A rule of thumb is that doubling the distance away will reduce loudness by 6 db.
Noisy and Intrusive - 60 to 70 decibels 60 db
TV at normal volume three feet away from the listener. 65 db
High setting for Air cleaner/purifier 70 db
A vacuum cleaner or hair dryer when being used by hearer.
Mildly Annoying - 55 to 60 decibels 55 db
Quiet radio or TV at three feet away. 60 db
Loud normal conversation.
Quiet - 35 to 50 decibels 35 db
Noise from a quiet room fan at a distance of three feet 36 db
Air cleaner/purifier at low setting 40 db
Quiet conversation at a distance of three feet. 50 db
The hum of a refrigerator at a distance of three feet. Birdsong at 15 feet, (not cockerel). Washing machines and dish washers in adjacent room.
Very Quiet - 15 to 30 decibels 20 db
Whispering 15 feet away. 25 db
Normal breathing at three feet away. 30 db
Almost Silent - 0 to 15 decibels 0 db
A mosquito flying at a distance of ten feet. Most people can't hear this. 10 db
Gently rustling leaves. 12 db
Humming from a light bulb. 15 db
A pin dropping onto a hard surface three feet away. Very quiet air cleaner/purifier
Of course, these decibel comparisons are very subjective, but they should give you a good idea of what noise level to expect from a given decibel rating.
Air Cleaner and Purifier Decibel Ratings
Whirlpool Whispure Whispure AP250
40 db low, 46 db high. Whispure AP450
39 db low, 52 db high. Whispure AP510
40 db low, 49 db high.