High-speed hand dryers are six times cleaner, produce 42 percent less CO2 than paper towel dispensers

Jun 09, 2014 by Marcene Robinson
Students use a blow torch and cotton swabs to collect bacteria samples from a paper-towel dispenser.

(Phys.org) —Don't touch that paper towel! High-speed hand dryers are cleaner, more environmentally friendly and save a bundle over time.

This is what some UB students discovered when they studied the economic, environmental and of paper towels and Dyson Airblades in campus bathrooms.

Equipped with blow torches and cotton swabs to collect bacteria samples, the students found that six times more bacteria grew on paper-towel dispenser push-and-crank handles than on the Airblades.

And through the life cycle of each product, the Airblades produced 42 percent less carbon dioxide and cost under $28 per year in energy consumption, compared to paper towels, which cost more than $900 per year.

With help from James Jensen and Berat Haznedaroglu, professor and assistant professor, respectively, in the Department of Civil, Structural and Environmental Engineering, the research team was awarded second place in the 2014 New York State Pollution Prevention Institute's R&D Student Competition.

The contest funds the students and provides them with the chance to design solutions to real-world environmental challenges.

"These outstanding students represent the best of UB: engaged, thoughtful and enthusiastic students devoted to making the world a better place for others," says Jensen.

For the study, the students examined four high-traffic and low-traffic men and women's bathrooms with Airblades and paper-towels dispensers in two North Campus academic buildings.

Using life-cycle assessment software, the group examined the manufacture, use and disposal of each product. The students measured paper-towel consumption, and used the Airblade's power meter to track the number of users and energy consumed.

Although the Airblade is more expensive up front—with a $4,000 unit price—the hand dryer has a four-and-a-half year payback period, the researchers say.

Bacteria were collected from several surfaces in the bathrooms as well. While the paper-towel dispensers contained large amounts of bacteria, hardly any organisms were found on the towels themselves.

Results also showed that few bacteria colonies grew on door handles and light switches, says student researcher Cassidy Edwards, a recent environmental engineering graduate.

Through a survey of bathroom users in one of the buildings, the students discovered that 65 percent of people opted for paper towels, spurning the Airblade despite its superior cleaning power.

"People in general think hand dryers are dirty," explains student researcher Alanna Olear, a senior major. "But they don't know a lot about the Dyson Airblade, which is cleaner than normal hand dryers. So their perception on regular hand dryers sways them to think that the Dysons are bad as well."

Unlike lower-end hand dryers, the Airblade contains an air filter and blows unheated air at a high velocity, creating a bad environment for bacteria growth, the researchers point out.

To combat Airblade misperceptions, the students are designing signage for campus bathrooms. The signs will tout the environmental impact of the Airblades by comparing savings to practical terms, such as trees planted, miles travelled and money saved.

The research team will use study results to encourage campus officials to install more Airblades on UB campuses.

Over the summer, the hope to publish their findings in peer-reviewed journals to allow other universities to see their work. They also will examine the collected bacteria samples to determine if any are pathogenic.

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not rated yet Jun 09, 2014
But there is a drawback.
Either Make them Foot-operated OR Run on Voice Commands!
Once it is done, people can turn around aiming their backs Too.
5 / 5 (3) Jun 09, 2014
Myth-busters found that the high speed air dryers spread bacteria much more than paper towels. As for culture rates on the handles of the dispensers, I can not recall the specific tests performed or exactly their test parameters. That is why I never wash my hands in public places!!!
3 / 5 (5) Jun 09, 2014
If they are even concerned about the "economic, environmental and social impact" of PAPER TOWELS, .....what of all the other innumerable instances of such impact?

Would anyone want to live with a government that had such coercive power over human behavior and industry that they even micro-regulate toilet paper? Of course the answer is no.

The first leason that should be taught these naive children, is that just because something is amendable to "scientitic research and analysis" does not mean that it is appropriate in a free society, to act on it.

For the liberals who were offended by the NSA,.... it is what "liberal progressives" ARE,..... to use science and technology and the force of government to "fix" every social and environmental "issue" that can be mined from statistical and/or social analysis. The NSA is nothing compared with what this stupid mentality implies for liberty.

5 / 5 (1) Jun 09, 2014
I haven't seen a push/crank dispenser for a while, as I have wondered where the stuff blown off by the air blast settles. I too am careful of where I decide to 'clean' my hands. At home I keep a chlorhexidine dispenser on the sink.

The point of paper hand towels is the bactericidal effects of the phenols in wood products, also why wooden cutting boards are still preferred in a clean kitchen.
not rated yet Jun 09, 2014
At the UWS campuses in Sydney the Dyson Airblades feel like your skin is being sandblasted. It's a very uncomfortable feeling so no wonder many students choose the paper towels, when available. Excuse my cynicism but did Dyson have any connection with this 'research'?
1 / 5 (1) Jun 09, 2014
These kids are comparing the best hand dryer (Airspeed) with one of the worst paper-towel dispensers (push and hand-crank). The paper-towel dispenser I used yesterday at a Sheetz had a single push, and was probably comparable to the air dryer for germ contact. (That Sheetz actually had both types of hand dryer side by side.)

Jun 09, 2014
This comment has been removed by a moderator.
5 / 5 (2) Jun 09, 2014
Seems to refute previous studies... I prefer paper towels so I can use it after drying my hands to open the door out of the restroom; if it swings towards me. If it's a crank type, I dispense the paper first before washing then rip it off and dry. Seems to me to be the most sanitary since so many people don't wash their hands anyway.
5 / 5 (1) Jun 09, 2014
the high speed air dryers also sound like a 747 taking off next to your ear
1 / 5 (1) Jun 10, 2014
Myth-busters found that the high speed air dryers spread bacteria much more than paper towels. As for culture rates on the handles of the dispensers, I can not recall the specific tests performed or exactly their test parameters. That is why I never wash my hands in public places!!!

Not to disparage Myth-Busters, but they're an entertainment show, not a research lab. How well controlled? Subject to critical review? Reproducible?

I hope you don't hold a position in which your encrusted hands are subsequently exposed to the public.
5 / 5 (1) Jun 10, 2014
"Results also showed that few bacteria colonies grew on door handles and light switches"

I don't buy that claim regarding public space. I will continue to use the paper towel to turn off the tap and open the washroom door.

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