How do I understand the decibel rating (db) on the hand dryer?

Facilities managers are becoming increasingly concerned about installing quiet hand dryers where ever possible. Loud hand dryers such as the Dyson Airblade, Xlerator and Airforce hand dryer can make washrooms and areas in close proximity less pleasant environments and lead to disturbance. We have put together a quick guide that will allow you to make more sense of the decibel levels when looking for a quiet hand dryer.

(Please note that since this article was originally written Dyson have brought out the AB14 DB version of the Airblade that is stated as being 50% quieter e.g 5 dBA. We agree that the new model is percievably quieter)

To help explain, here is how a decibel scale works. The smallest audible sound (near total silence) is 0 db. A sound 10 times more powerful is 10 db. A sound 100 times more powerful than near total silence is 20 db. A sound 1,000 times more powerful than near total silence is 30 db.

To put this into context:

Distance affects the intensity of sound, if you are a distance away, the power is greatly diminished. All of the ratings above are taken while standing near the sound. The db on hand dryers is usually measured 1m away from the air outlet of the hand dryer (please check individual specifications)

Any sound above 85 dB can have ill effects on hearing, the loss of hearing is related both to the power of the sound as well as the length of exposure. You know that you are listening to an 85 dB sound if you have to raise your voice to be heard by somebody else. Continuous exposure for eight hours of 90 dB sound can cause damage to your ears and protective equipment is recommended. Any exposure to 140 dB sound causes immediate damage (and causes immediate discomfort)

NIOSH Daily Permissible Noise Level Exposure

Hours per day / Sound level:

  • 8 hours = 85dBA
  • 6 hours = 86dBA
  • 4 hours = 88dBA
  • 3 hours = 89dBA
  • 2 hours = 90dBA
  • 1.5 hours = 92dBA
  • 1 hours = 94dBA
  • 0.5 hours = 97dBA
  • 0.25 hours or less = 100dBA

National Institute for Occupational Safety and Health (NIOSH)

Perceptions of Increases in Decibel Level:

  • Imperceptible Change 1dB
  • Barely Perceptible Change 3dB
  • Clearly Noticeable Change 5dB
  • About Twice as Loud 10dB
  • About Four Times as Loud 20dB

We hope this has given you an insight into what to expect the noise level to be like when noting the decibel level of a hand dryer.

If you would like to view our range of quiet hand dryers please follow the link below:

We also have a number of our hand dryers that have achieved the prestigious Quiet Mark which mean they are some of the quietest in their class.  These can be viewed by clicking here

For more information or for help in finding your ideal hand dryer, please call us on 1300 HANDRY or (+61) 1300 426 379, use our contact us page by clicking here or click to visit the website.  

You can also use our Intelligent Search Tool that helps you identify the perfect dryer for your location by clicking here.

In the trade? Don't forget we can set you up with a trade account for your purchases. We have wholesaler, contractor, public sector and charity discounts available, please don't hesitate to ask or find out more information by clicking here.