For more than 80 years hand dryers have existed now, allowing to dry hands after washing them with the help of different kinds of systems. Basically, these electrical devices can be found in all sanitary installations, where many people encounter each other, be it a large company, public institutions or in gastronomy. Devices with warm-air blowers are considered to be traditional hand dryers that makes water on wet hands evaporate with the help of warm air. These devices are therefore called warm air hand dryers.
Recently developed systems however are working with a high-performing blower which allows a quick drying of the hands through blowing away the moisture. The remaining wet residueson the hands are being counteracted with evaporation. Newer systems mainly use cold air, not least resulting in saving a great deal of energy. This already shows how the devices have to fulfil many different requirements depending on the individual needs of different user groups.
Image 3: Modern sanitary installation with hand dryers
The specific workings of a hand dryer mainly depends on the producer and the type of used technology. Generally, all devices have the purpose of drying hands with air streams. All devices basically work with a similar functionality, and they have been for more than 80 years. Inside the casing there is a motor that is switched on either by manually using a button or a corresponding sensor. It will then suck the air into the device, guide it through a filter in order to reduce germs and bacteria and will then lead the air into an air duct. In order to reduce the resulting sound volume, additional noise control systems are integrated, nowadays they can be found in almost every modern product. From the air duct of the device, the air is distributed with greater pressure and, depending on the system and technology respectively, ejected from the device with high velocity. Currently, producers are working on the most ideal discharge angle for the air to create a pleasant as well as quick and efficient drying.
2. Kinds of hand dryers
As explained in the beginning, there are two kinds when it comes to electrical hand dryers that can be differentiated from each other: warm air hand dryers as well as modern hand dryers.
|Warm air hand dryers||Modern hand dryers|
These devices suck in air from the environment and, finally heated up by the warm air blower, is released and blown out again. The warmed air evaporates water on the hands until a complete drying is achieved. With this operation it is important that the air is filtered, so that bacteria do not come into contact with the skin during the drying process and germs cannot be spread.
Compared to warm air hand dryers, modern hand dryers have a higher performing blower. A wide selection of new models is furthermore used with cold air, thus consuming less energy that would have been necessary for creating warmth. The blower allows an air pressure that blows away water or moisture from the hands. Many producers guarantee a drying time of only 10 to 15 seconds here.
When it comes to costs of purchase, these devices amount to prices starting from 100 Euro. The final prices is decided by aspects like design, used materials and sensors as well as brand name. At Creoven devices can be found that have a non yellowing synthetic material that ensures a longer durability.
In order to live up to hygienic standards, modern devices are mostly operated by sensors. Here the formation of germs can be reduced many times over according to manufacturer's data.
For a longterm reduction of spreading of germs and bacteria, the devices should be maintained regularly.
In consequence of the used modern technologies, such devices are more expensive when it comes to purchase. A standard device depending on the used technology has costs of about 500 Euro per piece.
Hand dryers are used where hygienic and economic systems are demanded in sanitary installations. Amongst other things they include:
The workplace ordinance (Ger.: Arbeitsstätten-Richtlinie ASR) issued by the Federal Ministry of Labour and Social Affairs which shows the requirements regarding condition and equipment of company washrooms, acknowledges hand drying devices as hygienic as well as a suitable alternative to drying hands with textile towel dispensers or throwaway towels. This goes for toilet as well as washroom installations. Another important aspect for example could be the IP codes.
4. Advantages in comparison with paper towels
It is not always uncontroversial when hand dryers are compared to the use of paper towels. The dispute revolves around the question which kind is more hygienic. Some say paper towels are more hygienic, however other studies show that there is no grave difference between both systems. The decision about hand dryers is obviously depending on the individual sanitary installation, yet the following advantages can be noted when making a comparison with paper towels:
Image 7: Paper towels cause additional costs for their disposal
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Image 7: © Robert Kneschke - Fotolia.com