More than hot air: Which hand dryers save energy, dry fast?

ShutterstockMile Atanasov
Hand dryers can be very energy efficient, or not.

Earlier this summer, hand dryer maker Dyson released an e-mail linking to a video that demonstrates how one of its competitors' hand dryers potentially can blow washroom air containing bacteria, viruses and even fecal matter onto your hands.

Of the competitor's hand dryer, the video said, "It sucks in the dirty air and blows it straight onto your hands so you think your hands are clean … but are they?"

Other Dyson videos focusing on two other competing hand dryers make similar claims — that the two dryers just redistribute dirty air.

Regardless whether true, what the videos show is how much more complicated and confusing a hand dryer buying decision has gotten in recent years.

In this highly competitive space are many types of hand dryers from which to choose — "eco" models, ones with sophisticated filters, "hands in" dryers that require emptying of water, ones touting anti-bacterial coatings and even ones with LEDs incorporated into the design.

Complicated, confusing or not, what is clear about hand dryers is their less intensive environmental impact than paper towels. 

Excel Dryer had a life cycle assessment study conducted by Quantis, an international life cycle assessment research firm, which was peer reviewed to ISO 14040 Standards.

The study determined that when compared to traditional electric hand dryers and paper towels (virgin and 100 percent recycled content), Excel Dryer’s XLERATOR hand dryer reduces the Climate Changing Score (carbon footprint) of hand drying by 50 percent to 75 percent.

Also according to Excel Dryer, in contrast to paper towels, which can cost $15 to $30 or more per case, the energy costs of using a hand dryer amount to pennies per day. The average cost of paper towels is 2 cents per hand dry versus 1/10th of a cent using an XLERATOR hand dryer.

According to Dyson, the annual operating cost of its Dyson Airblade Tap hand dryer is $48 as compared to $1,460 for paper towels.

Robert Green, U.S. head engineer at Dyson, said paper towels come with hidden costs such as space for paper towel stock, repeated restocking time (staffing), trash can liners and waste removal.

"And let us not forget about plumbing clogs that can happen when someone inevitably tries to flush paper towels," Green said. "Clog removal and other plumbing costs associated with paper towels can add up over a year and cause frustrations for bathroom users.

"Many companies choose recycled paper towels to be more environmentally friendly, because they may think they can be recycled over and over again. Yet, this is another misconception. In truth, recycled paper towels typically cannot be recycled again, so they end up in landfills or being incinerated."

Huge opportunity for energy savings

When it comes to energy efficiency, there are stark differences between hand dryers. Excel Dryer, for example, says its XLERATOR uses 80 percent less energy than conventional hand dryers. World Dryer says its SMARTdri series uses 40 percent less energy than competitive high speed hand dryers and only 12 percent of the energy of traditional dryers.

Hand dryers can become much more efficient when not using heat. The XLERATOReco from Excel Dryer, for example, uses no heat and only 500 watts compared to the 1,500 watts of other XLERATOR models that use heat. According to World Dryer, automatic hand dryers cost about 7 cents per 200 uses with heat and only 4 cents per 200 uses without heat.

The better the dryer design, the faster hands are dried. Dry time impacts energy consumption as well as overall bathroom efficiency. Most high-speed hand dryers dry hands in about 10 to 14 seconds. Others can take as long as 30 seconds. HygenEco Systems, in a video on its website that describes its Bio Jet Drier, says its "hands in" drier can dry hands in as little as seven seconds.

 

While maintenance labor is reduced significantly when eliminating paper towels, some hand dryers require more maintenance than others. "Hands in" models, for example, include small tanks that capture water. These tanks have to be emptied on a routine basis.

Different approaches to hand drying hygiene 

As mentioned, hygiene is certainly something to consider when making a buying decision. Air in a restroom environment does need some type of filtration but not all hand dryers include filters.

World Dryer, with its "hands in" VMax model, offers a HEPA filter with odor neutralizing tablet. The TRI-Umph high-speed hand dryer from American Specialties, Inc. features a three-layer filtration system consisting of a HEPA filter, carbon filter and anti-microbial filter.

Most HEPA filters remove at least 99.97 percent of particles and microorganisms that are up to 0.3 microns in size. Not all HEPA filters are the same. The highest level possible is H14. 

American Dryer’s EXTREMEAIR CPC uses cold plasma clean technology that the company says kills germs. Cold plasma is ionized air that contains positively and negatively charged ions that attract and break down germ molecules without the use of chemicals.

Whether a hand dryer uses heat does impact hygiene. According to Dyson’s Green, "NSF International P335 protocol actually deems warm air commercial dryers as unhygienic, because warm air dryers remove essential oils from the skin and can cause skin tightness and/or chapping."

 

Most hand dryers include some type of anti-bacterial coating. The ffuuss hand dryer, for example, has been treated with Biomaster antibacterial additives whose active ingredient based on silver ion technology prevents the growth and formation of new bacterial cells.

At least two companies have solved the challenge of water dripping from one’s hands when moving from the sink to the hand dryer. They have incorporated the hand dryer into the sink system. With the Dyson Airblade Tap hand dryer, water for washing and air for drying come from the same fixture. Similarly, Bradley, with its all-in-one Advocate Lavatory System, enables one to get soap and wash and dry one’s hands — all above the wash basin.

Hand dryers go high tech

Some hand dryer makers use LED lighting as either a decorative item or as part of an alert system — to let one know that a filter needs changed or water tank needs emptied. The Bio JetDrier from HygenEco Systems, for example, incorporates blue LEDs in its design. 

At least one company, ffuuss, has incorporated Bluetooth technology into its hand dryers. If there is a maintenance issue, an e-mail alert can be sent to an engineer or other person. According to ffuuss, the system currently runs in Android but soon will be available in other systems.

According to Dyson’s Green, when considering the purchase of hand dryers, it is important to look for external, third party certifications or approvals. Green says, for example, that the Dyson Airblade hand dryers are certified by NSF International and are the only hand dryers to be certified to the NSF P335 drying protocol.

As another example, Excel Dryer’s XLERATOR is GreenSpec listed, qualifies for several LEED credits, is Made in USA certified, and endorsed by the Green Restaurant Association.

Finally, sound level also should be considered when purchasing hand dryers. A look at the five hand dryers on the American Dryer hand dryer website page showed decibels as low as 63 and as high as 83. Dyson’s Green said decibel readings can be as high as in the 90s and 100s.

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