Book 14, Question 57
Why Are Vacuum Cleaners and Hair Dryers So Noisy?
Vacuum cleaners and hair dryers are noisy because fast fans push the air hard! The air races through narrow gaps and swirls in messy ways. That swirling air makes hissing and roaring sounds that we call noise.
More fun facts
- A vacuum cleaner is a fairly loud sound, around 70 decibels.
- EU rules restricted vacuum cleaners that make more noise and heat than suction.
- Vacuums using more than 900 watts or louder than 80 decibels were banned from sale in the EU.
- Engineers study the air flowing through vacuum nozzles to design better cleaners.
- Sound is measured in decibels, and a vacuum is a relatively loud sound.
Sources: National Park Service, BBC, NASA
Questions kids ask
How loud is a vacuum cleaner?
About 70 decibels.