Hand dryer is an electric appliance designed to dry wet hands by blowing warm air. Used instead of towels or paper napkins, mainly in public toilets.
How the hand dryer works and works
The device has a similar design with a household hair dryer for drying hair because it works on a similar principle.
The dryer consists of the following elements:
- A heating spiral.
- The inclusion node.
The dryer case can be open or closed. To use an open-type device for blowing warm air, you just need to put wet hands from below. At the same time, the droplets coming off them will fall on the floor. The closed body involves drying when the hands are placed inside. In this case, the accumulating moisture accumulates in the tank and then flows into the sewer through a special drain. Thus, in addition to external design differences of the case, the closed-type devices imply a more complex installation with the connection to the sewer.
The fan provides air blowing, which speeds up the process of drying wet hands. The stream, supercharged by a cooler, passes through a heated spiral, so it heats up. Hot air blows the hands and ensures their drying in 10-30 seconds.
The main energy-consuming dryer device is the heating spiral. It takes up to 90% of the electricity used to heat it. The remaining 10% is spent on fan power.
A button, a keyboard switch or a motion sensor can be used as an inclusion node in the hand dryer. Applying the latter eliminates the need to touch the device to run it.
Pros and cons
The use of dryers is economically more profitable than the use of paper towels. The device does not need maintenance. If you use towels, then periodically need to dispose of them, removing the urn, as well as buy them a replacement. Choosing a dryer saves time and reduces costs. Of course, the use of such a device is accompanied by the consumption of electricity, but its cost is definitely lower than the spent towels.
This device is convenient, practical and economical, but its use still has certain drawbacks:
- The hand dryer is dilapidating the skin.
- Hands are intensively blown by air from the room, which can be saturated with bacteria.
If you constantly use the dryer for hands, the skin on them will begin to dry up and becomes painful. Sensitivity to blowing hands hot air in different people is different, it all depends on the type of skin. But definitely with frequent use of dryers, it will suffer.
Also, the disadvantage of dryers is that the fan captures the air in the room, which is usually the toilet and directs it on his hands. As a result, a lot of bacteria can settle on the skin that sticks well while it is wet.
Contact and contactless dryer
One of the most important differences between different dryers is the type of inclusion node. Contact devices use a button or key in their capacity, and contactless IR has a sensor that reacts to movement in the blowout zone.
Contact devices are budget devices. However, they have several distinct advantages:
- Included without false positives.
- Do not disconnect spontaneously until the hands are completely dry.
- Do not require adjustment, except to adjust the temperature.
The main drawback of button dryers is that to turn them on and off you need to touch the device. This is not hygienic, as in the public restroom the button can touch several hundred people a day, so it is a breeding ground for bacteria.
The contactless hand dryer is preferable in terms of hygiene because to trigger it you just need to hold the palm a little below the hole blowing, where the sensor is directed. Thus, direct touching to the device is excluded.
At the same time, the contactless device has some drawbacks:
- Falsely triggered, for example, from the movement of flying insects.
- It can be disconnected before the hands dry, so you need to remove under the sensor.
As for the lack of a false positive, it is in all contactless devices, but early disconnection occurs only when the wrong too economical settings of the dryer. The fact that the device triggered on the movement can continue blowing literally 5 seconds, which is clearly not enough for drying, so it has to run again. This problem is solved by increasing this time in dryer settings.
Some devices work only when near their blowing is moving. That is, they are not tied to a certain length of time, how much more work is needed after the signal from the sensor. They blow out the air while there is movement. However, if the hands remain within the range of the sensor and are stationary, the device will stop after a few seconds. Thus, none of the sensor systems works perfectly and has certain drawbacks.
Criteria for choosing a dryer
Hand dryer is quite a popular device, which is produced by dozens of companies. In this regard, the market of this equipment is saturated with devices of different configurations. This creates some difficulties in choosing when buying. In this regard, to buy the most suitable for a specific purpose device, you need to navigate on several criteria:
- The material of manufacture.
- How to turn it on.
Dryers are made of plastic and metal. Plastic devices are much cheaper. They are recommended to be used in rooms with a small passability of people, it can be service toilets. Such devices are quite reliable, but not designed for rough attitude. The steel dryer for hands is much stronger. Other than that, it can be anti-vandal. That is, when it is installed in an unguarded public toilet, you can not worry that the device will be able to bend or damage in another way.
Hand dryer can have a power level of 1-2.5 kW. There is an opinion that the weaker the device, the more economical it is in terms of energy consumption. However, this is a misconception. Low power reduces only the price of the device itself, but not the cost of drying one pair of hands. A powerful 2.5 kW device dries hands in 10 seconds, while a 1 kW dryer can handle it in 30-40 seconds. It is not difficult to understand that a powerful dryer is turned on less in time, so the actual cost of drying at an expensive and budget device is almost the same.
The choice of the dryer by the noise level in most cases is not carried out, as these devices are mainly designed for installation in public restrooms. If you plan to install in a residential apartment, then naturally the quieter the fan, the better.
An important parameter by which dryers differ is their speed. They are ordinary and high-speed. A conventional hand dryer heats the air strongly and directs it to the skin in a warm but slow flow. As a result, the hands dry out in 20-40 seconds, which depends on the power of the device. In the case of high-speed dryers, the air is heated slightly, but blown out quickly. Due to this, the water is simply blown away by the stream and falls small drops into the collection of the device, from where it flows down the drain.
Almost every dryer has a complete set of mounting mounts. Usually, it’s four dowels with self-cutters.
Installed on the wall:
The hand dryer is placed on the side of the sink, not above it. This minimizes the possible queue in the toilet. If you hang the device over the sink, then everyone in the queue will have to wait until everyone first washes his hands, and then they dry, all the time being in one place. When the device is on the side, after washing hands you can move away from the sink, making room for the next visitor.
Most dryers only need to be connected to the electrical grid. They can be inserted into the socket or join the wiring in a hidden way. Individual devices with a closed body should also be connected to the sewer.
Why the cost of different dryers is significantly different
The cost of hand dryers may vary several times. This is primarily due to the fabrication material. The cheapest plastic dryers, more expensive metal painted. The best are stainless steel devices, as their body is almost eternal.
More expensive dryers have a mechanism for adjusting the temperature of air heating and the speed of flow. This allows you to adjust the operation of the device depending on the season. In winter it is better to make the flow hotter, and for hot summer a little colder, so as not to overheat the user.
Also, the cost of the device depends on its power. The cheapest dryers can dry hands for 40-60 seconds. This is a very long time, given that many devices do it in 10 seconds. That is, the installation of the latter can reduce the stay of a person in the room of the restroom for half a minute, which is very important when the toilet has a large attendance, and near its door formed a queue.