Air Hand Dryer Downfalls

Less Effective Drying

According to AsapSCIENCE, users spend on average 45s on a standard warm air dryer drying their hands to 97% moisture reduction. In contrast, users spend 10s using a paper towel to achieve the same 97% moisture reduction result, and using only 5s, paper towel users can achieve greater than 85%+ moisture reduction. In reality, though, users dont spend the full 45 seconds when using air hand dryers--on average, users only spend 22s using the hand dryers, causing only 70% moisture reduction. Because of this, users tend to wipe their hands on their clothing after to finish the drying process, which causes a drastic increase in bacteria on the surface of the hands.

Less Sanitary

There have been multiple studies done that have concluded air hand dryers to be less sanitaary than using paper towels. These studies include:

• Are hand dryers actually full of bacteria? – New York Times
• The article highlights a study done for a microbiology class, where a student incubated bacteria found on the outlet of a hand dryer and found drastic results. See an image of what the student found to the right!
• Microbiological comparison of hand-drying methods: the potential for contamination of the environment, user, and bystander - Journal of Hospital Infection by E.L. Best, P. Parnell, M. H. Wilcox
• Air bacterial counts surrounding jet air dryer were 4.5x higher than hair surrounding warm air dryer, and 27x higher than bathrooms with paper towels and not hand dryers. This contamination scales down, reaching a span away from the dryers up to 2 meters.
• Evaluation of the potential for virus dispersal during hand drying: a comparison of three methods – Journal of Applied Microbiology by P.T. Kimmit and K.F. Redway
• The jet air dryers (JAD) dispersed an average of greater than 60 and greater than 1300-fold more plaque-forming units (PFU) compared to the warm air dryers (WAD) and paper towels (PT), respectively. The JAD dispersed an average of greater than 20 and greater than 190-fold more PFU in total compared to WAD and PT at all distances tested up to 3 m respectively.
• Paper Towels vs Hand Dryers – AsapSCIENCE
• Friction plays a huge role in the removal of bacteria from the hands. Paper towels provide material friction, which is more effective than the air friction from hand dryers.

Other Downfalls

Though compared to the other two major downfalls of air hand dryers these may seem trivial, they still can play a big role in swaying the overall opinion of users. These last couple downfalls are that air hand dryers are loud and they cannot be used for other non-local purposes such as cleaning spills, blowing noses, and washing windows.