Humidifier warm or cold steam. Humidifiers cold evaporation. With cold steam

Almost every person in his life has experienced such uncomfortable sensations due to very dry air, such as a sore throat, peeling of the skin, a constant desire to sneeze.

The steam humidifier is becoming more and more popular among consumers

The only correct solution in such a situation is to purchase a humidifier. There are a large number of such devices, but evaporative type humidifiers are becoming more and more popular every year.

Features of the functioning of the humidifier with hot steam

Steam humidifiers in their functioning are somewhat reminiscent of the well-known electric kettle. In order for the water to evaporate quickly, it is heated to a maximum temperature.

In turn, to prevent an increased level of humidity in the room, these devices are equipped with a special sensor (hygrostat). Thanks to him, when the humidity reaches the required level, the device automatically turns off.

Some modern evaporative humidifiers heat water up to 100 degrees in a specially equipped chamber, which is much faster than bringing the entire supply of water to a boil in the device. As a result, the steam comes out warm instead of hot, which is much safer and does not require a lot of electrical energy.

Steam humidifiers are equipped with a special safety system, thanks to which the device automatically turns off in case of insufficient water level.

In most cases, such humidifiers for the home come with a container for aromatic substances and nozzles for inhalers.

Features of the operation of a humidifier with cold steam

Unlike hot steam vaporizers, which are compared to an electric kettle, a cold steam humidifier is compared to a basin filled with water, where it gradually evaporates. In other words, evaporation is produced naturally, but forced blowing off of air masses by a fan built into the device is not excluded.

A number of natural evaporation appliances use drum systems (they are regularly moistened with water to produce more intense evaporation). The drum is made of a large number of plates, which contain notches and special holes. These holes produce water retention, which helps to increase the usable area of ​​the drum.

Steam humidifiers have another name - "air washers"

Humidifiers of cold evaporation have another name - "air washers". This is due to the fact that they carry out the passage of air masses from the room through themselves, leaving dust particles, allergens and other harmful microorganisms that are in the air in the aquatic environment.

Most cold air humidifier kits do not have a humidistat, since the evaporative process is natural and cannot be influenced.

The main advantages of steam devices

Evaporative type humidifiers have the following advantages:

1. High level of efficiency. There is an opportunity in a short time to increase the level of humidity in the room up to 100%.
2. High steam temperature. The steam that the device emits has a temperature that is enough to kill most harmful organisms. In addition, steam is one of the additional sources of heat in the cold season.
3. No response to water quality. Steam-type humidifiers do not require refilling with distilled water, since the resulting steam does not contain salts, and during the evaporation process, water is purified from non-volatile impurities.
4. Does not require consumables. The steam humidifier does not include nozzles and replaceable filters that need to be replaced periodically.
5. A steam-type humidifier quite often uses the role of an inhaler and a fragrance. The steam that these devices create is sterile, and if essential oils are added to a special tray, the device can also be used for medical purposes.

Weaknesses of a steam humidifier

The steam humidifier has several disadvantages.

Cold steam humidifiers, like hot steam devices, have a number of disadvantages:

1. High power consumption.
2. Only expensive device models have the ability to control the level of humidity in the room.
3. If there is a hot steam generator in the entire area of ​​the room, there is a significant increase in the temperature regime. In the case of the winter period of the year, this disadvantage can be attributed to the advantages.
4. Due to the fact that the device includes automatic shutdown sensors, such humidifiers are quite expensive.
5. A number of models are very dangerous for children, because the steam generator generates steam at a very high temperature.

The main nuances when choosing a steam humidifier

When choosing a device for humidifying indoor air, you should approach this process with special care, since this is not all that will be determined by the type of humidifier and the approximate cost.

When purchasing a humidifier, you should pay attention to the following features:

1. The area of ​​the room where the device will operate.
2. The level of consumption of electrical energy.
3. The presence of a hygrostat in the configuration (applies to a device where the steam generator emits hot steam). The presence of this component makes it possible to turn on the humidifier at night without worrying that the air will be waterlogged.
4. The presence of a number of additional components - nozzles for an inhaler, a container for infusing essential oils, an electronic type of control.

Popular steam humidifiers

At this point in time, there are a huge number of different humidifiers for air masses, but the following are among the best steam humidifiers of 2017:

Humidifier Boneco Air-O-Swiss 7136 does not make noise during operation

1. Boneco Air-O-Swiss 7136. Included in the number of devices that emit cold vapor. It does not make any sound during operation. The package includes a hygrostat, which allows you to maintain the required degree of humidity in the room even at night. The tank of the device allows you to hold 5 liters of water. Possesses function of automatic shutdown and electronic control. Among the shortcomings can be noted the appearance of white plaque on the walls.
2. Beurer LB50. It is one of the hot steam humidifiers. The results from the use of the device are best seen when it is installed in a room whose area does not exceed 40 square meters. It has a fairly simple and understandable to the common man electronic control. In the configuration of the device there are special pillows that prevent the occurrence of scale. Contains the function of automatic shutdown in case of insufficient water. The capacity of the water tank is 5 liters. There is a special compartment for the infusion of aromatic oils. Among the disadvantages of this model of humidifiers is the absence of a hygrostat.
3. Stadler Form Fred Black. It stands out among other steam humidifiers with its unusual design. It is best to use the device in an area that does not exceed 40 square meters in size. It is quite economical, since the water consumption is quite low. According to the manufacturer, during the operation of the device there will be a minimum amount of plaque, which will be quite easy to remove. During operation, the device does not make any noise, signals an insufficient amount of water. Among the negative aspects of the device is a high level of electrical energy consumption.
4. DELONGHI UH 800. It has a rather original design and low cost. Effectively functions in a room whose area does not exceed 25 square meters. Can work without interruption for 20 hours. Contains a special compartment where you can put aromatic oils.
5. Venta LW15. It is one of the cold evaporation humidifiers. The device is able to maintain indoor humidity from 40 to 60% without the use of a hygrostat. Due to the automatic shut-off function, there is no chance of waterlogging of the air masses in the room. If you wash the tank where water is stored once every 2-3 weeks, then plaque does not form on its walls. Due to the special design, quite a small consumption of electrical energy. It makes almost no noise during operation.
6. LG SAHSBP30GA0 Steamer. It is one of the hot steam humidifiers. It is characterized by rather low noise during operation. It has a fairly high power, which, combined with a low cost (4 thousand rubles), attracts more and more people to the device. Among the disadvantages is the high consumption of electrical energy - 295 watts.
7. Boneco 7135. The device is equipped with automatic shutdown sensors, a hygrometer, and has an electronic control. It works almost silently, the noise level is 25 dB. In addition to everything else, the device is decorated in a modern style, which allows it to be installed in almost any room interior.

After reviewing the above list of popular steam humidifiers, you should not immediately run to the store to purchase one of them.

The main thing to do is to remember their properties, and depending on them, choose the right device for yourself.

It is very important to initially decide on what kind of steam the humidifier should produce - cold or hot. Only having decided on this, you can already proceed directly to the selection of the model. This is very important, because looking for a cold humidifier with a hygrometer will not bring any results, and you will only waste your own time.

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Among household appliances, a special place is occupied by a system for increasing air humidity, which is based on a hot or cold humidifier. Modifications of both differ in the principle of operation and purpose. Cold steam humidifiers, unlike hot steam humidifiers, do not heat water. This is in the second case, under the influence of temperature, steam is formed, through which the room is saturated with moisture. And in the first, steam is obtained by breaking water into droplets using vibration. But in any case, the air humidifier uses cold steam for its intended purpose. And it is a special container in which, like in a household kettle, the liquid turns into steam. But in a hot device, it is brought to 100 degrees. In addition, unlike a pot or kettle, a cold humidifier has a slightly different design.

Air humidifier - hot steam as a basis

In most cases, electrical appliances emit hot steam. It is known that water boils at a temperature of 100 degrees Celsius, and its heating in the apparatus is carried out using built-in electrodes, between which an electric current passes. The air humidifier is hot, as well as cold steam emits wisely, therefore it is an economical and safe device that ensures the maintenance of a normal air level.

Regardless of the type of device, the main requirement is for water quality. It must be well mineralized and have the necessary electrical conductivity. These requirements are easily met with ordinary tap water. But due to the fact that the tap fluid is far from perfect in terms of quality, it is necessary to periodically clean the device from scale formation.

All devices offered in stores have built-in water level sensors in the tank, which allows the user to add liquid in time, bringing it to normal. The safety of the device operation is ensured by the protection system, which automatically turns off the device in the event that the liquid in the tank is used up, as a result of which the connection between the electrodes is interrupted and the circuit is opened.

Cold steam humidifiers – better?

Continuing the conversation about this device, you should focus on the safety that the air humidifier has - hot steam can cause burns, but in this case the device has a durable case material (plastic) with increased heat resistance. The tool will not turn on when the filler cap is open, which is also an additional safety element.

Not all models of cold humidifiers are equipped with a hygrostat or hygrometer - sensors that show the level of humidity in the room. In this case, it is better to purchase them separately.

Every person from the school course knows that 70% of it is water. However, the moisture contained in the surrounding atmosphere also affects human health. What can a low moisture content in the air lead to? First of all, a person's immunity weakens, the skin loses its elasticity and healthy appearance, the person becomes weak, gets tired quickly. From all of the above, young children are especially affected.

Why do you need a humidifier?

Most of the year each person spends indoors. There is practically no person in the open air. As a result, the moisture balance is disturbed, leading to various diseases.

In the summer months, such an imbalance is almost not felt, however, in the winter, the difference in air humidity in the street and indoors is very noticeable. First of all, this is due to the heating of the premises by the heating system.

The nose and throat of a person will be the first to feel a lack of moisture in the air, there will be a feeling of dryness, then the human skin and lips begin to dry out.

If you notice similar symptoms in yourself or your loved ones, then you need to take immediate action.

Now we have come close to the question - how can you maintain the natural level of humidity in the house or at work?

Using a humidifier will solve problems with dry air .

What are home humidifiers?

Type 1. Fan or cold steam humidifiers

The most traditional humidifier. According to the principle of action, it resembles a basin with water. In these humidifiers, all processes occur naturally. That is, moisture evaporates from the container with moisture, which is inside the device. First, special sponges absorb water, and only after that it enters the air. The task is to create an air flow that enhances and activates the process of moisture evaporation. Especially important.

With this method of air humidification, without much effort, it is possible to achieve that the natural air humidity in the room becomes 50-60%, which is the norm.

The advantage of such humidifiers is the fact that when the air humidity is less than the permissible one, the fan starts to work with greater activity, which leads to more moisture evaporation. As soon as the humidity in the room reaches 50-60%, the fan slows down and the moisture evaporates much more slowly.

Such humidifiers work almost silently and for as long as necessary. Also, during their operation, no steam is formed in the room. However, their dimensions are somewhat different from other types of humidifiers. Due to the fact that the design provides for a fan, the humidifier has large dimensions. In the care of such devices are very simple - it is enough to occasionally rinse the sponges from dust and sediment, which occurs as a result of interaction with water.

Benefits of cold steam humidifiers

• economical energy consumption;
• affordable cost;
• steam is not visible, so the appliance does not attract children;
• flavoring capsule included.

Disadvantages of cold steam humidifiers

• it is necessary to change the filter quite often - once every two months;
• the maximum possible humidity level is not more than 60%.

Note: in order for the humidifier to work at maximum power, it is enough to place it near the heater.

Type 2. Humidifiers for the home "hot steam"

The principle of operation of this humidifier is based on heating water to a boiling point of 100 degrees. Water turns into steam and thereby evaporates in the room, increasing the humidity of the air. Only this type of humidifier can raise the humidity in your room up to 100%. Now nothing can stop you from doing inhalations or steam baths at home. It should be noted that such steam is absolutely sterile and does not contain harmful impurities.

However, such humidifiers are quite noisy, which can interfere at night, especially for a small child. In addition, heating water to the boiling point requires additional energy costs. Or maybe a moisturizer? You will also need to periodically clean the heating element when scale builds up on it.

Benefits of hot steam humidifiers

• hot steam cleans the air of all harmful impurities;
• even if the water in the device is dirty, the steam will be clean;
• the humidity level in the room can reach 100%;
• performance is higher than other types of devices.

Disadvantages of hot steam humidifiers

• traumatic especially for young children;
• work noisily;
• consume a large amount of electricity.

Type 3. Ultrasonic humidifiers for home

These devices appeared on store shelves relatively recently, but very quickly won the favor of many buyers.

The principle of operation is based on high-frequency oscillations of the membrane inside the humidifier. As a result, water turns into steam, but this steam does not heat up and remains cold.

A distinctive feature of this type of humidifier is absolute noiselessness, and they are able to raise the humidity in the room to the desired level in the shortest possible time. The maximum level of humidity possible during the operation of an ultrasonic humidifier is 90%.

On many models of ultrasonic humidifiers, you can find built-in hygrometers. This greatly simplifies the process of controlling the humidity in the room.

However, the disadvantages of such a device include the presence of steam in the room, albeit cold, but from an aesthetic point of view - the steam in the room is not a very pleasant sight. Also, plaque forms in the humidifier after a short time of operation of the device. However, the difficulties associated with its elimination do not arise - just wipe the inside of the device with a damp cloth. Replacement cartridges, which are sometimes included with a humidifier, do not always help to cope with the problem of plaque.

Benefits of ultrasonic humidifiers

• a wide range of devices of different designs and sizes;
• completely safe to use;
• when the set humidity level is reached, or all moisture has evaporated from the device, the humidifier will turn off by itself;
• work silently;
• consume a small amount of electricity;
• The maximum possible humidity level in the room is 90%.

Disadvantages of ultrasonic humidifiers

• it is necessary to use cleaning filters or distilled water;
• steam is not evenly distributed in the room.

Important characteristics of air humidifiers

1. Power.

One of the most important characteristics of the device, indicating how much moisture the humidifier is able to convert into steam in one hour and then maintain a given level of humidity for a long time.

From the point of view of this parameter, the cold steam humidifiers are the least efficient. Their productivity does not exceed 300 ml/h. Humidifiers "hot steam" occupied the "golden mean" - their performance is represented by a capacity of 400 ml / h to 700 ml / h. Ultrasonic devices are considered the most effective - their performance allows you to achieve indoor humidity at the level of 90%.

Note: the power of one air humidifier is designed exclusively for the area of ​​\u200b\u200bone room.

2. Filter

• Photocatalytic. Allows you to clean steam from harmful impurities by 95%. At the same time, bacteria, viruses die, gases decompose. An important advantage is a long service life.
• Nera. Belong to the category of fine filters. They allow to achieve almost one hundred percent purification of steam from dust and dirt particles with a size of at least 0.3 microns. Disadvantages: short service life (no more than a year), high cost.
• Ionizing or electrostatic. Captures charged particles. It copes well with dust, soot, however, does not clean the steam from toxins. Advantages: affordable cost, can be subjected to repeated cleaning.
• Carbonic. Perfectly cleans steam from smoke, unpleasant odors and chemicals. It is used in conjunction with another filter and requires replacement within the period specified by the manufacturer.
• UV. Kills fungi and bacteria and does not require special care.

3. Air enrichment

• Ionization. Ions, due to their negative charge, have an effect on dust, as a result, dust particles settle on the floor. In addition, ions are able to prevent the reproduction of microbes.
• Ozonation. The enrichment of the air in the room with ozone contributes to its disinfection.
• Aromatization. The air in the room will always be fragrant. Essential oils can be used as fragrances.

4. Additional options

• Hygrostat. With it, you can always monitor the level of humidity in the room. In addition, the hygrostat makes it possible to turn the device on and off automatically.
• Steam direction adjustment. Thanks to this function, moisture will evaporate strictly in the specified direction.
• Intensity adjustment. If necessary, you can set the required intensity of the device.

Some models of humidifiers are equipped with a control panel, internal lighting and a timer.

It depends only on you - what kind of air you and your closest people will breathe. We need air every second, so why not make sure that it is clean, moist, healthy and pleasant to breathe. In the next article, we will look at the topic - their advantages and disadvantages.

Humidifiers improve indoor air quality and relieve the symptoms of low humidity: cold headaches, dry skin, sneezing and coughing. During the dry winter months, when heating systems are very dry, humidifiers are a great way to add missing moisture to the air. Dry air is often the source of many ailments, including flaky skin, itchy eyes and chapped lips, and can cause sore throats and nosebleeds. These symptoms occur regardless of whether you have allergies or asthma. Low levels of humidity in the air can even damage wood furniture and cause cracks. Having a humidifier in your child's room will help your child sleep comfortably, as well as prevent colds and the spread of germs during flu season.

Humidity levels:

The optimum level is between 25% and 55% relative humidity. Inexpensive or allows you to easily control the level of relative humidity in the room. A moisture content of less than 25% in the air does not add health to our body at all, but do not forget that humidity above 55% can cause such unpleasant phenomena as the growth of mold, bacteria, fungi and dust mites. You can often spot elevated levels of humidity by looking at your windows: condensation on windows is a sure sign. Most humidifiers have an information hygrometer that allows you to independently monitor the amount of moisture you add to the room. More expensive models have a built-in hygrometer that not only takes readings from the sensors and tells you the humidity level in the room, but also allows you to set the exact level of humidity that the device will maintain.

Types of Humidifiers:

The stores currently offer a wide range of different types. They differ in size (tank volume from 1 liter) and humidification method (cold steam, hot steam and ultrasonic). The largest humidifiers are called console humidifiers, they are able to humidify several rooms or very large areas at once. Room humidifiers are small in size and are best suited for one small, medium or large sized room in your home and office. Here is a brief overview of the existing types of humidifiers:

Cold steam humidifiers (traditional)

The most common type. These appliances use the principles of natural evaporation, which is the cleanest method of humidification. The humidifying filter is located in the case on the pallet and absorbs water. The fan then blows the dry air from the room through this moisture-laden filter, causing the water to evaporate into the room, thereby increasing the air's humidity. The filter also traps and traps any impurities and minerals that may be present in the water, making the humidified air completely pure. Most filters need to be changed about every 2 months, although some models are self-cleaning or use reusable filters.
Model examples: ,

Pros:
* Humidifying filter provides clean and impurity-free evaporation
* Very low power consumption
* Fans can be powerful enough to cover a large area

Minuses:
* Fans may be noisier than other types of humidifiers (noise level depends on fan speed
* Most filters need to be changed approximately every 2 months
* Bacteria and mold may appear on the filter (can be reduced with special antibacterial additives)

Hot steam humidifiers

These humidifiers use a heating element that boils water in the humidifier and releases it into the air as warm vapor. If you live in a cold climate, using hot steam humidifiers will help make the room slightly warmer (as opposed to cold steam humidifiers, which can do the opposite). These humidifiers are quieter than evaporative cold vapor humidifiers because they do not use a fan. Instead, the heating element simply boils the water, turning it into pure steam that rises into air free of all minerals and impurities. Any mineral content that was present in the water remains in the humidifier and will not be released into the room air. Mineral deposits remaining in the appliance can be removed with vinegar. Some models also use additional demineralizing filters that are able to absorb calcium before it settles on the humidifier.
Model examples:

Pros:
* Silent operation
* No need to change filters
* Clean, demineralized steam
* Some models have a special tank for spraying soothing aromatic oils

Minuses:
* Higher power consumption (the heating element uses more electricity than other humidifiers)
*Most appliances are only for small rooms
* There is a risk of burns for small children if the humidifier is accidentally knocked over

Ultrasonic humidifiers (cold or warm steam)

the quietest among all such devices. They are so quiet that they are often described as almost silent. An ultrasonic humidifier uses the power of high frequency sound waves to vibrate a metal diaphragm at an "ultrasonic" frequency, breaking the water into many small vapor or mist droplets. This mist-like vapor is propelled into the air by a very small and quiet fan. Any minerals or impurities that are present in the water are released into the air in the mist, which is why many ultrasonic humidifiers use demineralization cartridges that serve to trap impurities in the water before they enter the air, although they are usually not 100% effective. If you are having problems with "white dust" settling on surfaces near the humidifier, the solution is to use distilled water. In some ultrasonic humidifiers, there is also, which helps to avoid the growth of bacteria in the water, and also protects against the sensation of cold. Model examples: ,

Pros:
* Quiet, near-silent operation
* Does not require filter replacement
* Low power consumption (when using cold steam)

Minuses:
* If distilled water is not used, impurities may settle in the form of "white dust" (in some models, this amount can be reduced using a replaceable demineralization cartridge)
*Most models are only for small rooms
* have a special reservoir for spraying soothing aromatic oils

Humidifiers disc cold steam (air wash)

In humidifiers or other humidifiers, a high-speed rotating disk or roller throws water into a diffuser, which then breaks the water into tiny droplets that are then released into the air as a visible mist. The humidifier disk usually rotates very quietly and does not require filter replacement. However, minerals and other impurities that are present in the water can enter the room as a fine mist. These minerals tend to settle on surfaces such as furniture and can lead to what is known as "white dust", which can appear as an ultra-fine layer of dust on surfaces surrounding the humidifier. Thus, it is desirable that only distilled water be used as it lacks minerals. Model examples: ,

Pros:
* Silent operation
* No filter replacement required
* Low power consumption

Minuses:
* If you do not use distilled water, impurities will be released into the air in the form of "white dust"
* Designed for small rooms only
* No humidity control

In addition to the types of humidifiers described above, several additional unique features have appeared:

Humidifiers with UV protection against bacteria

Some humidifiers are now equipped with a UV sterilizer, which uses UV light to kill up to 99.9% of the bacteria, germs, and viruses present in your humidifier's water. This type of humidifier is intended primarily for families with babies and young children, as well as those who are worried about the spread of germs, bacteria and viruses. Previously, only hot steam humidifiers had this option, but now ultraviolet sterilization has become available in some models of cold steam humidifiers.

Pros:
*Adds extra bacteria protection and water sanitization
* Available in both hot and cold steam models

Minus:
* UV lamp needs to be replaced, usually after several months of continuous use

Direct Fill Humidifiers

While most humidifiers use removable water tanks that need to be carried and filled at the sink or tub, there are a few models that do without a tank entirely and allow water to be poured directly into the humidifier itself. In these simple models, you can use any utensils you have to fill them, even a small cup. If you have health limitations when lifting or carrying fairly heavy water tanks, these models are designed specifically for you.
Model examples:

Pros:
* No heavy water tanks to be lifted, turned upside down and carried around
* Quieter than other humidifiers: no "gurgling" of water when filling the tray with water
* Easy to clean

Minuses:
* Need to have your own water tank on hand (e.g. pitcher or cup)
* Stagnant water inside the humidifier increases the chance of mold growth

Which one to choose?

When buying, consider the two most important criteria: the size of your room, and the type of humidifier you prefer.

Air humidification methods

There are only three ways to humidify the air in your room - steam, ultrasonic and the principle of cold evaporation, among which the principle of cold evaporation is recognized as the best technology for humidifying the air compared to the other two methods of humidification.

Steam method of air humidification- water boils like in a kettle, evaporates and humidifies the air with hot steam.

In steam humidifiers, along with undoubted advantages, such as unconditional hygiene and price, there are several very serious disadvantages. For example, the danger of getting burned by hot steam. High probability of waterlogging. Also, calcium. Yes, yes, this eternal calcium that settles on everything it touches. You can use distilled water. You can change to clean cartridges, endlessly nervous about finding new filters or descalers .... As a result, the unfortunate device is thrown onto the cabinet, and the name of the manufacturer's company is not mentioned except in abusive constructions. Yes. Cheap is not always cheerful.

By the way, I forgot to mention the power consumption. It doesn't come out that cheap.

Ultrasonic air humidification method- an excellent method if you need to moisturize quickly, efficiently and inexpensively. For example, if you have tropical plants in your winter garden, then you can’t think of a better way.

At the moment, such devices are considered the most high-tech devices that consume a small amount of electricity. It is based on the method of splitting water into tiny drops - water from a tank, falling on a plate vibrating with a high frequency, is split and ejected in the form of a small cloud.

At the exit, we have a mysterious and incomprehensible jet of absolutely cold steam, which runs counter to our ideas about steam in general...
For about a week you will be fascinated and delighted to watch this miracle of technology, feel it and invite all your friends to touch this magical cold vapor. After two weeks, everyone will lose interest, and after three months - yes, calcium again. Ultrasonic humidifiers have cartridges to collect lime. The cartridges in the device must be changed, otherwise the accumulated calcium will begin to come out and settle on furniture, plants, etc. with a white coating. Well, on everything, in general. In general, if there is a responsible manufacturer that will conscientiously produce and supply filters and cartridges for its devices for a certain number of years, the problem is solvable. No - well, you will have one more device on your closet, and in your vocabulary - one more swear word. It's a pity, of course, but a fact.

Cold evaporation method Still, it is not in vain that it is recognized as the best in the whole world. Recognized by whom? No, not by us, of course, although we fully agree with this. This method of humidification has received recognition among those millions of users who have purchased air humidifiers operating on the principle of cold evaporation.