Hand dryer
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A hand dryer is an electric device found in a public washroom that is used to dry hands. They may either operate with a button, or more recently, automatically using an infrared sensor.
Advantages
Hand dryers have been popular with industries for their apparent economies. Energy use (on a life cycle basis) is claimed to be reduced by as much as 80% in comparison with paper towels,[1] the principal alternative; consequently, together with reduction in other areas, hand dryers can cut costs by as much as 90%.[2] Neither do they require maintenance after being installed,[3] whereas paper towel stocks need to be replaced, and used paper towels removed.
Due to the reduction in litter and waste in comparison with paper towels (which cannot be recycled), hand dryers are also claimed to be better for the environment. One source claims that an average fast-food restaurant using paper towels, annually, results in 9 fully-grown trees being cut down, and 1,000 pounds of landfill waste created (paper towels alone amount to 35% of landfill space currently used), though many are often unaware of these consequences.[4] Even before the paper towels are used, each ton has claimed 20,000 gallons of water in chemical cleansing.[5]
Hand dryers, are also claimed to be more hygienic (though note the counterclaims below under "disadvantages"). Doctors at the University of Ottawa claim that "the blowing of warm air may lead to an accelerated dehydration of the skin surface, thereby affecting the viability" of the microorganisms, and that the warm air may "penetrate all the crevices in the skin, whereas absorbent towels may not reach such areas, even though the skin appears dryer".[6]
Disadvantages
The general public find most hand dryers, particularly early models, slow to use. (As a result, newer high-speed models are available to the market.) In addition, if a facility completely replaces its towel dispensers with hand dryers, then people often no longer have access to the towels for things like cleaning up spills, wiping up messes on their body or clothing, etc. Some also may find hand dryers to be too noisy.
Because hand dryers can be costly to purchase and install, facilities managers must do a careful cost analysis to determine whether they are cost effective in their building.[7]
Handwashing for Life, an association of food service suppliers that includes paper makers[8], argues that hand dryers have "no place" in food areas "mainly because they are neither effective or fast."[9]
Other studies have found the hand dryer to be less hygienic than the paper towel. One paper (Ngeow YF, Ong HW, Tan P. Dispersal of bacteria by an electric air hand dryer. Malays J Pathol. 1989 Aug;11:53-6.) found that air dryers dispersed marker bacteria in a radius of three feet and onto the investigator's laboratory coat. Another study (Rebecca Montville, Yuhuan Chen and Donald W. Schaffner, Risk assessment of hand washing efficacy using literature and experimental data, International Journal of Food Microbiology, Volume 73, Issues 2-3, 11 March 2002, Pages 305-313) found that hot air dryers had the capacity to increase the bacterial count on the skin, and that paper towel drying decreased skin bacterial count. This is agreed upon by another study (Gould D. The significance of hand-drying in the prevention of infection. Nurs Times. 1994 Nov 23-29;90(47):33-5), which also found that the mechanical action of paper towel drying removed bacteria, which is something hand dryers cannot do.
Developments
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Dyson have recently released a new type of hand dryer, the Dyson Airblade. It dries hands in 10 seconds using a thin blade of pressurised air, and is more cost effective for energy usage than traditional hot air blower hand dryers, as well as more environmentally friendly, saving 83% in energy in comparison to conventional hand dryers. Based on 200 uses a day for 365 days a year, the Airblade would cost £30 to operate for that full year[10].
It seems that the Dyson Airblade may be a copy of the Mitsubishi Jet Towel, which uses a similar design and technology.[11] The Jet Towel has been used in Japanese bathrooms since 1997.[12]
Another UK company, Excel Dryer Ltd have also released a similar machine, advertised as being 98% cheaper than paper towels, and more environmentally friendly[13].
An American company, American Dryer has developed a high speed hand dryer with a 10 second drying time. The eXtremeAir is more economical at a cost of $390 US. It works by blasting a user's hands with a stream of heated air at 185 MPH. This breaks up the surface tension of the water for quick removal and evaporation. It uses about 80% less energy than conventional hand dryers which require 2300 watts of electrical power for 30-40 seconds.
Manufacturers
List of manufacturers of hand dryers:
See also
References
- ^ Life
- ^ American Dryer.com, 10th October 2006
- ^ American Dryer.com: Maintenance
- ^ Grist.com: On paper towels vs. hand dryers. "…it doesn't matter very much whether you use the blow dryer or the paper towel. The impact of how you dry your hands is so small that you'd be far better off spending your time and energy on more important issues…".
- ^ American Dryer.com: Environment
- ^ Ansari, Shamin A., et al. "Comparison of cloth, paper, and warm air drying in eliminating viruses and bacteria from washed hands." American Journal of Infection Control 19 (1991): 243–249. This was itself cited by American Dryer.com: Hygiene and American Dryer.com: Bibliography
- ^ "Hand Dryers vs. Paper Towels: What is the cost comparison". EnergyIdeas Clearinghouse Q&A. Washington State University Extension Energy Program. Retrieved 2007-04-04.
- ^ Buzzle Editorial 7/31/2006
- ^ Handwashing for Life, "Paper Towels Win in Effectiveness & Speed"
- ^ Dyson Airblade Website
- ^ Article about Jet Towel
- ^ Jet Towel Website
- ^ Excel Dryer's website