How do hand dryers work?

by | Jul 23, 2014 | Home & Garden

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Hand dryers dry hands using electricity. Hand hygiene is one of the leading causes of bacterial spread and it is very important to have clean hands to stop the spread of communicable diseases. The presence of disease bearing microorganisms is much higher in a public restroom than it is in most other places and as it is intended that the restroom is for use by the public the concentration of germs and bacteria can be extremely high. As many germs that cause disease spread by touch, hand dryers were developed so that people did not have to come into contact without touching a roll of paper or cloth towel. Hand dryers both only help with the management of hygiene as well as reducing waste from the use of paper towels. How do these machines work?

Sensing: When hand dryers were originally developed the electric power was engaged by pushing a button. When the button was depressed, the machine started to blow warm air on the users hands. After a predetermined time the hand dryer turned off whether the user’s hands were completely dry or not. If it was necessary to completely dry the hands often the button had to be pushed a second time. This is no longer the case, when the user places his or her hands under the machine, a motion detector senses their presence and the machine turns on and stays on until the hands are dry and withdrawn. In this way the modern machines are more convenient and save energy.

Heating and drying: Hand dryers have a heating element which is made from Nichrome which is an alloy of chromium and nickel. As ambient temperature air passes through the heating element it warms up. The heating coil is normally heating the air by about 50 degrees F over the temperature of the restroom. The warm air is expelled from the dryer through an outlet which faces downwards. The user’s hands are placed under the vent, the pressure and the warmth of the air is enough to evaporate water from the hands. The high velocity air blows water droplets off the hands and the warmth dries the hands completely. Originally it took about 45 seconds to dry the hands but modern fast-dry machines do the job in less than 15 seconds.

Hand dryers are one time investments which continue to serve their purpose for many years with a minimum of maintenance. The savings over the use of paper towels can add up to thousands of dollars over the lifetime of the dryer.

Hand dryers are without a doubt the most cost effective and hygienic way to dry hands in a public restroom. World Dryer has been providing hand dryers for over 50 years and are recognized as the world’s leader in hand dryers.

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