The Hand dryer is an electric machine which makes use of heating element and an air blower to dry the hands. It is commonly used in the public bathrooms as a cost-effective alternative to paper towels. It may either operate with the push of a button or automatically using a sensor.
Due to the reduction in litter and waste in comparison with paper towels, which cannot be recycled, hand dryers are claimed to be better for the environment. Majority of the environmental impact of a hand dryer occurs during its use, the environmental impact of paper towels is predominantly in the material production and manufacturing stages.
The earliest hand dryer was patented in 1921 by R.B. Hibbard, D. J. Watrous and J.G. Bassett for the Airdry Corporation of Groton New York. This machine was sold as a built in model or freestanding floor unit that consisted of an inverted blower (much like a handheld blow dryer) that was controlled by a floor pedal. Known as "Airdry The Electric Towel", these units were used in restrooms, barbershops and factories. Airdry Corporation moved to Chicago and San Francisco in 1924 to centralize their distribution.
The hand dryer was later popularized in 1948 by George Clemens, who founded World Dryer and invented the Model A, World Dryer’s flagship model. In 1993, Mitsubishi Electric introduced a new type of hand dryer "Jet Towel’’, that blows jets of air on both sides of the hand, pushing the water off rather than evaporating it.
Typically, installed hand dryers make over 80 decibels of sound at a distance of 10 ft (3.0 m) while in operation. It is much louder for the user and may exceed safety limits for children whose ears are at the height of the device. Some units, however, are designed to be quieter at the cost of drying speed.