Guide Hand Dryers
Common terry towels to share are not an option in public washrooms. Bacteria and germs would quickly gather and proliferate in the damp cloth. But how hygienic are electric hand dryers? What is the difference between all of these models and how do they work? Find out more about hot air hand dryers, quick dryers and paper towels.
- Functionality of hand dryers
- Hot air and cold air dryers
- Requirements for hand dryers
- Where to apply the devices?
- Benefits in comparison to paper towels
Functionality of hand dryers
You might not believe it, but electric hand dryers have been around for more than 90 years! The first unit was invented in the year 1925 in Stuttgart, Germany. Electric dryers are primarily used to dry freshly washed hands and can be installed right next to the wash-bowl for maximum convenience. Today hand dryers of many different kinds made by many different brands can be found in almost any place where a lot of people use the same washroom. This includes company office buildings, public institutions or restaurants. There two main differences between hand dryers:
One one hand we have the traditional units that work with warm air. They are therefore known as hot air or warm air hand dryer though they mean exactly the same thing. The first “Electrostar” hand dryer used exactly this technology. The same technology is still used today though much more sophisticated. On the inside of the hot air dryer there is a metal heater coil that is heated up with electricity. Ambient air is sucked into the device, heated up and transported onto the wet hands. The hot air causes up to 95% of the water on the surface of the skin to evaporate. The drying time and energy consumption have long been improved. Old models took up to 45 seconds to dry hand, nowadays short intervals of 10 – 30 seconds are the new standards.
Vortice hot air hand dryer
Inside of the hot air hand dryer
A technical revolution was the introduction of the cold air hand dryer in 2006. The new system was first implemented with Dyson’s “Airblade” model. These so-called jet hand dryers allow for an even faster drying time. These models are now also sold by other brands with a similar technology. The powerful air blower also uses ambient air but doesn’t heat it up first. The water doesn’t evaporate but is rather just blown off the skin. After 10 – 15 seconds the user has dry hands. High-end products even achieve this in less than 10 seconds. Despite the powerful output these models consume less energy. Cold air hand dryers are therefore ideal for washrooms with high traffic.
The exact construction of a hand dryer mostly depends on the manufacturer and the technology it uses. All electric heaters have the same basic concept, meaning they use a high velocity stream of air to dry hands. On the inside there is a motor that is activated either with a manual push button or a contact-free sensor. Ambient air is sucked into the device and transported through the filter where the number of germs and bacteria is reduced. Integrated sound suppression helps to reduce the noise level. Through this channel gas is distributed under high pressure giving it the high velocity we feel on our hands. At the moment, manufacturers are trying to find the ideal exit angle to provide a pleasant, fast and efficient drying.
Hot air and cold air 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 GBP. 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 GBP per piece.
Requirements depend on the individual needs of different user groups such as:
Modern sanitary installation with hand dryers
Hygiene: The devices need to ensure a hygienic use. This concerns properly functioning filter systems that prevent spreading of germs and bacteria. Another aspect of improving hygiene is the use of sensors that make a use without direct contact possible.
Energy efficiency: The goal of modern hand dryers is the energy efficient drying of hands that is made possible with speed on one hand and the use of just little energy in the shape of electricity on the other hand.
Economic efficiency: Whether in gastronomy, in companies or public institutions - costs for sanitary installations should generally be as low as possible. When it comes to hand drying devices this means that costs for purchase, maintenance as well as installation and durability need to be financially profitable.
Sound intensity: A certain sound level of hand dryers cannot be prevented. Depending on the sanitary installation this aspect however can be perceived in different ways. For example in smaller washrooms the sounds emitted by the device are perceived as more disturbing as it would be the case in larger premises. Therefore the type of the device depends heavily on the respective conditions in the sanitary installation.
Performance: Another important aspect for the choice of the perfect hand dryer is the performance of the devices. In the end, the decisive factor is how often the devices are used on a daily, weekly or monthly basis by the respective target group.
Vandalism-proof: An electric hand dryer with IK09 or IK10 will triumph over the most destructive rowdy. Shock-proof housings, scratch-proof coatings and protection from cigarette burns are provided by most of our devices. However, not only violence but also frequent use leaves its mark.
IP ratings: Another important aspect is the protection from water and object ingress. Splashing water proof dryers are perfect for use in damp environements where splashing from the sink cannot be avoided. This also makes them ideal for application on camping grounds underneath alfresco outdoor situations.
Design: Owners of hotels, nightclubs and restaurants often spend huge sums of money on the perfect interior design. Every detail is in harmony with the overall décor. A cheap hand dryer from the nearest DIY market disrupts the concept which is why our manufacturers opt for a timeless yet chic design.
- Public toilets, that have a high amount of visitors every day. Modern hand dryers allow a quick drying of the hands with a relatively low energy balance and without creating a great number of additional waste. Smaller washrooms also offer enough space for such a hand drying device, as they can easily be mounted to a wall.
- Big companies and commercial areas also use hand dryers more often. Apart from the hygienic and ecologic aspect, the devices save additional staff and storage costs that would be necessary for example when disposing of and storing paper towels. As modern producers promise hand drying within just a few seconds, the aspect of time can no longer seen as a disadvantage.
- In gastronomy branch, hand dryers are also used more commonly. In this case energy efficiency, hygienics and cost optimisation are also the basic, decisive factors when it comes to choosing this system.
Image 6: Great demand in sanitary installations
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:
- Considerably less impact on the climate: According to a study conducted by the Swiss non-profit organisation climatop®, greenhouse emissions of selected hand dryers as well as paper towels were compared over a lifetime cycle. The result shows that hand dryers performed remarkably better than paper towels. The main reasons for this result are that modern devices have a smaller power consumption, and the impact on the climate caused by the energy consuming production of paper or textile are a severe, negative argument for paper towels.
- No staff expenses: Paper towels need to be re-filled, which means one or several employees are necessary. This workforce is an additional, significant expense factor that, depending on the sanitary installation, can be saved with the help of hand dryers.
- No storage costs: Paper towels need to be stored in a certain quantity. This requires a corresponding storage capacity that must not be embezzled when it comes to company expenses.
- Problem of disposal drops: The disposal of paper towels also means additional costs that can be prevented with a hand drying device. Furthermore, the creation of waste can be reduced, making for a sustainable handling of available resources.
- Regulated net consumption: Most people use considerably more paper towels than the recommended one sheet of paper. This aspect does not only complicate the calculation of needed quantity, but also causes unnecessary waste that could otherwise be prevented.
- Look of sanitary installations: Depending on staff capacities, it often happens that sanitary installations with paper towels quickly look untidy, because bins are overstuffed with paper towels or paper is laying on the ground.
Image 7: Paper towels cause additional costs for their disposal
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Image 6: © Photographee.eu - Fotolia.com
Image 7: © Robert Kneschke - Fotolia.com