Comparison Electrolux EHAW-7510D vs Redmond RHF-3301

— Humidifier. A device for increasing the humidity in the room. A humidity of 40-60% is considered optimal for a person, and 60-70% is recommended for children, especially during illnesses. At the same time, the need for additional moisture may arise in any climate — especially during the heating season. The humidifier allows you to adjust the microclimate in the house. And its various forms of execution, including the column and wood imitation will help to fit it into the interior of the room without any problems.

— Air washer. Water humidifiers, which, in addition to the main function of humidification, additionally purify the air from all kinds of contaminants. It is achieved by passing air through the water, as a result of which dust is retained. Full-fledged air purification is out of the question, but such humidifiers provide basic filtration.

— Purifier A more advanced device for cleaning the air from various contaminants. The quality of such cleaning in different models can be different — from the simplest mechanical filtration to the removal of chemical contaminants and odours.

— Bactericidal recirculator. Unlike air purifiers with replaceable filters, the main task of recirculators is not to clean the air as such but to fight viruses, bacteria, mould and other unpleasant microorganisms. The princi...ple of operation of most such devices is the same; it is based on relatively powerful ultraviolet lamps with a wavelength of ~254 nm. It should be noted that a long stay in the same room with the device turned on is not recommended, since during its operation ozone can be released, which in high concentrations is harmful to the body.

Combined devices are produced that combine the capabilities of a humidifier and a purifier. Such devices in our catalogue are classified in the “Air humidifiers” section, and the “Air purifiers" section includes only specialized purifiers, without a humidification function.

At the same time, not all models are homemade. So there are compact portable devices for use in the car. Such models, in addition to being powered by the cigarette lighter through their own cable or USB port, have the ability to install in a car. Some models are mounted on a dashboard, others are shaped to fit perfectly in a cup holder, etc. However, nothing prevents them from being used in a home environment; only their performance will obviously not be enough, because such devices are designed for small volumes.

— Ultrasonic. The most common type of operation: the working element of the device vibrates at ultrasonic frequencies, due to which the water falling on it is broken into tiny drops that form a suspension in the air. Such a water cloud has room temperature, which means that there is no risk of burns; some models may have a warm steam function. Thanks to this, as well as the low noise level, it is ultrasonic models that are considered optimal for children's rooms. That is why there are children's humidifiers with the appropriate design. Also, the advantages of such devices include simplicity, compactness, good work efficiency and economy. The main disadvantage of this type of humidifier is the exactingness of the quality of water: it must be demineralized, otherwise, the salts contained in the water will settle on objects in the room, creating a hard-to-remove plaque.

— Evaporative. The simplest option, also called "traditional": air is driven by a fan through a cartridge moistened with water, and humidification occurs due to natural evaporation. Water humidifiers have a very low intensity: it may take several days of continuous operation to achieve the required humidity level. On the other hand, it is practically impossible to re-moisten the air with such a device: in fact, exactly as much water evaporates from the cartridge as needed at a given temperature and humi...dity. In addition, such devices can be used even in fairly large rooms that an ultrasonic or steam humidifier cannot handle — up to 40 m² or even more. They work very economically and often quietly. And the quality of water can be almost anything — the main thing is to monitor the condition of the filters and change them at the frequency indicated by the manufacturer.

— Steam. Humidifiers of this type work by heating water with an electric heater. One of the main advantages of such devices is the high efficiency and speed of humidification. In addition, the high temperature of the steam contributes to hygiene. And even with not very high-quality water, steam does not create a white coating, as in the ultrasonic models described above — when heated, only water evaporates, and all salts remain in the device. On the other hand, the heaters will have to be descaled periodically. The steam devices themselves turn out to be quite noisy and high-consumption — water is consumed fast. In addition, hot steam requires some caution: it is not so easy to get burned by them, but such a possibility still exists.

A very conditional parameter that slightly characterizes the purpose based on the size of the room. And depending on the height of the ceilings, layout, building design and equipment, actual values may differ significantly. However, this item represents the maximum recommended room area for which the device is designed. In fact, this paragraph indicates the maximum service area in air humidification mode: use on a smaller area is quite acceptable, but the device simply does not have enough performance for a larger space. We also note that the area is indicated based on a standard ceiling height of 2.5 - 3 m. With higher ceiling heights, the effective humidification space decreases; it can be recalculated using special formulas.

When choosing by area, it is worth taking a certain reserve, but it should not be too large - otherwise the device will turn out to be overly powerful, bulky and expensive.

Types of filters provided in the device with the purifier function (see "Type"). Some models allow you to install additional filters that are not provided in the standard configuration; however, for a full guarantee, it is better to immediately buy a device with the necessary equipment. Here are the most popular types of filters nowadays:

— Pre-filter. The filter installed first at the inlet to the device. Usually provides the simplest mechanical filtration from relatively large contaminants, for which it makes no sense to use more advanced and expensive solutions like HEPA or NANO elements (see below). And some devices are not equipped with any other filters at all, except for the pre-filter.

— Electrostatic filter. The action of such a filter is based on the property of the smallest particles in the air to acquire an electric charge and be attracted to an oppositely charged object. It provides effective cleaning from dust, smoke and soot; in addition, the air is also slightly ionized, which can also be attributed to the advantages (for more information about ionization, see "Features"). But with odours and harmful volatile substances, such a filter handles poorly. The design of an electrostatic filter is based on a set of metal plates that are charged; the plates need to be regularly cleaned of dirt, they do not require other maintenance, so the filter life is almost unlimited.

— HEPA filter. Dry fine filter. It is similar in design to co...nventional mechanical filters, but differs from them in terms of the principle of operation: dirt particles do not so much get stuck between the filter fibres as they stick to them. As a result, HEPA filters can retain contaminants that are much smaller than the gaps between the fibres, which ensures high filtration efficiency. Different types differ in quality. So HEPA 10 can capture at least 85%, HEPA 11 — 95%, HEPA 12 — 99.5%, HEPA 13 — 99.95% and HEPA 14 — 99.995%.

— NANO filter. Porous ultrafine filter. Detains particles with a size of thousandths of a micron (millionths of a millimetre), cutting off not only small mechanical impurities but also individual molecules of organic substances (although such a filter is still inferior to a charcoal one in terms of molecular purification efficiency).

— Charcoal filter. Filter based on activated carbon or other similar adsorbent. It can effectively retain volatile molecules of various substances, thanks to which it perfectly eliminates odours. On the other hand, the charcoal filter is demanding compliance with the service life: after the resource is exhausted, it not only loses efficiency but also becomes a source of harmful substances, so in such devices it is especially important to change the filter elements on time.

— Photocatalyst. The principle of operation of such a filter is to decompose the harmful substances that enter it into neutral components (mainly water and carbon dioxide) under the action of ultraviolet radiation and a special catalyst. It is not designed to remove mechanical impurities, but it does an excellent job of removing odours and harmful volatile impurities, and also effectively destroys bacteria and viruses. At the same time, the catalyst is not consumed during operation, and the reaction products evaporate on their own — so that the filter has an almost unlimited service life, while it practically does not require maintenance. The main disadvantage of photocatalysts is their high price.

— Antibacterial. Under this name, several types of filters are combined, designed primarily for the destruction of harmful microorganisms. So, some antibacterial filters use an active substance that destroys the protein shell of microbes, others use an ionizer or ozonizer, others use UV radiation, etc. So the specific features of such a filter and the rules for its maintenance should be clarified separately.

– Ultraviolet lamp. A lamp that processes passing air with UV radiation. This treatment provides a bactericidal effect: ultraviolet light neutralizes most bacteria, viruses and fungi.

In addition to those described above, modern cleaners may include other, more specific types of filters — for example, to neutralize formaldehyde or ozone, which can be useful in some types of industries.

— Hygrostat. A feature that allows you to maintain a constant level of humidity in the room. The humidifier with a hygrostat constantly monitors the humidity of the air, and if it falls below the set value, it turns on, restoring the necessary microclimate. This is much more convenient than manually controlling the humidity.

— Air flow adjustment. A switch that allows you to set the desired level of airflow at the outlet of the humidifier. It plays the role of an intensity regulator: the higher the speed of the evaporator or fan, the more intensively the device works and the faster the desired humidity level will be reached. However, note that, unlike a hygrostat, this function does not automatically turn off when the desired humidity level is reached.

— Ionizer. A device for saturating the air with negatively charged ions. It is believed that the presence of such ions in the air has a beneficial effect on health and well-being, and also creates a feeling of freshness. In addition, ionization helps to reduce the amount of flying dust — it settles faster on various surfaces.

— Aromatherapy. A device for saturating the air in the room with pleasant smells at the request of the user. In humidifiers, aromatic oils can be added to the water for this purpose; in air purifiers, special replaceable cartridges are used....r>
— Ozonation. The function of saturating the air in the room with ozone. Ozone (a substance made up of three oxygen atoms) is a powerful natural disinfectant. In small quantities, it not only purifies the air of pathogenic bacteria but also creates a feeling of freshness. At the same time, an excess of ozone hurts well-being and can lead to serious diseases. So in some cases, ozonation is not just unnecessary, but also undesirable — especially if there are other sources of ozone in the room, such as laser printers or copiers.

— Night mode. A special mode of operation, designed for nighttime. Usually, in this mode, the device reduces the fan speed, thereby reducing noise. And some models in the night mode also maintain higher humidity levels than in the daytime — it is believed that this is the optimal microclimate for sleep.

— Warm steam. The function of preliminary heating of water; provided in ultrasonic and water models. By default, such devices produce "cold steam" at room temperature; it may contain pathogenic bacteria. To destroy them, the water in the tank can be preheated to temperatures of the order of 80-85 °C.

— Water purification. Water purification in humidifiers can be implemented in different ways, the most popular is the filtration cartridge, usually ceramic. It allows you to remove excess salts and other minerals, thereby softening the water and reducing the amount of deposits. This type of cleaning is predominantly used in ultrasonic humidifiers. In air washers, silver rods are more often used for water purification. Silver has antibacterial properties due to the formation of silver ions in water.

— Filter indicator. An indicator that indicates the need to clean or replace the filter. It is usually installed on expensive electronically controlled models. This feature is especially desirable for models with charcoal filters: at the end of their service life, such a filter begins to release harmful substances instead of absorbing them, and it is extremely important to replace them on time.

— Auto mode. The function used in devices with air purification capability (see "Type"). Devices with this function can independently monitor the state of the air and respond to it — turn it on when pollution is detected and turn it off after the air is cleaned. And some advanced models are even able to adjust the intensity of work to the level of pollution. Anyway, the auto mode saves the user from having to monitor the state of the air himself and enable/disable the cleaning programme. — Timer. The function that provides automatic shutdown after a user-defined time. It eliminates the need to turn off the device manually, which is not always convenient. The timer can be useful, for example, if the humidifier is turned on at night, or if it works in a children's room with a sleeping child who is not wanted to be disturbed.

— Automatic switch-off. In humidifiers with this function, a special sensor monitors the presence of water in the reservoir, and when it runs out, it turns off the device. It avoids wasted energy and, in steam models (see Type), also prevents overheating.

— Evaporator rotation. The ability to rotate the evaporator nozzle to change the direction in which steam is supplied. This function allows you to distribute the moisture produced by the device throughout the room as evenly as possible.

— top water fill. The ability to add water to the device from the top side — usually through a removed cover or a hole in the cover. Usually, humidifiers with this function can be refilled right during operation — this is more convenient than turning off every time, or even disassembling the device to add water. Among other things, this feature can be useful if the device is used in a children's room — it allows you to do it without unnecessary noise and not disturb the sleeping baby.

— Child lock. Usually, child lock means the ability to block device controls so that a curious little child cannot turn it on, turn it off or change settings on its own. Such a lock is disabled in a non-obvious way, accessible to an adult, but not to a child — for example, by simultaneously pressing two buttons.

— Display. The display makes the control of the device more convenient. The screen can display data on the current operating mode, the set timer, the status of the filter (in purifiers) or the water tank (in humidifiers), etc. Information about the status of humidity and temperature can also be displayed. Displays, usually, are equipped with expensive models with electronic control.

— Humidity indicator. The presence of a special indicator, mostly digital, allows you to show the level of humidity in the room.

— Temperature indicator. Similar to the dial described above, which displays not the humidity, but the temperature in the room.

— Air quality indicator. A function more related to air purifiers. With its help, you can understand how polluted the air in the room is and whether it needs to be cleaned. It can be achieved with the help of indicators — for simple models it lights up when the air condition is inappropriate, for more advanced ones it shines in different colours depending on the air quality.

— Control via the Internet. The ability to control the device via a smartphone, tablet or other gadget. Features of such control depend on the type of device (see above). So, in humidifiers and combined models, communication is carried out via Wi-Fi, and control access can be obtained not only on site but also via the Internet, from anywhere in the world. At the same time, both a special application for a mobile device and a page in a regular browser, which can also be opened from a computer, can be used for control; these details need to be clarified separately. Purifiers mainly use Bluetooth for communication, and only a gadget with an installed application can be a control device. However, this function can significantly make life easier for the user. And it's not just the ability of remote control: the application is often more convenient and intuitive than the classic control panel, and it can provide various additional features.

– Voice assistant. Device support for one or more voice assistants (assistants) such as Amazon Alexa, Apple Siri, and Google Assistant. Recall that the voice assistant is a service that allows the user to control various devices and receive various data using voice commands. However, it is not the built-in voice recognition system, but compatibility with an external gadget (phone, tablet, smart speaker) on which the corresponding assistant is installed. It is this device that will recognize the user's commands and transmit them to the humidifier/purifier. However, this control method is often more convenient than traditional options like a remote control or a mobile application.

— Remote control. A remote control is included with the device. The convenience of this function is obvious — it eliminates the need to approach the device every time to turn it on, turn it off, etc. Note that control from the remote control, unlike control via a smartphone (see above), is usually available only within direct visibility.

— Backlight. A decorative function that does not affect the main functionality. The illuminated body of the device looks beautiful in the dark and can even be used as a night light.

The type of control provided in the device.

Note that mechanical and electronic devices can use the same elements - buttons, rotary knobs, sliders — and, as a result, almost do not differ from each other in appearance. The difference lies in the fact that the mechanical control directly affects the working part of the device (for example, when the knob is turned, the resistance of the rheostat that regulates the power changes), and the electronic control sends a signal to the control circuit, which accordingly changes the parameters of the device. The advantages of mechanical ones are simplicity, reliability and low cost. However, it allows you to adjust only basic functions, and the accuracy of the adjustments is low. In turn, with electronic control, various additional features can be provided and individual operation parameters can be very precisely adjusted. But such control is more complicated and expensive. Electronic control can also be performed in the form of touch controls, which gives the device elegance and elevates it to a more advanced level.

It is the operating time of the humidifier with a full tank. It depends on the volume of the tank and on the water consumption (see below for both). For models with humidity control (see "Features"), this parameter can be indicated in different ways: in some cases, the maximum duration of the operation is given (at the minimum output humidity), and in others — vice versa. Nevertheless, according to the declared figures, it is quite possible to estimate the operating time at least approximately.

The rate at which the humidifier uses water. Knowing this speed and the volume of the water tank (see below), you can determine the operating time. Also, this indicator can be used to evaluate the performance and speed of the device: the higher the water consumption, the more it evaporates into the air per unit of time. Accordingly, a high-consumption device allows you to quickly achieve the desired humidity, all other things being equal.

Note that for models with humidity control (see "Features"), the maximum consumption is most often indicated, at the highest humidity settings. And in evaporate devices(see "Type"), the claimed consumption will be achieved only with dry air (30% or less) — at higher humidity, evaporation will slow down and water consumption will decrease.

The volume of the water tank installed in the humidifier. Large capacity allows you to work longer without refuelling but affects the dimensions and weight of the device. Therefore, manufacturers choose the volume based on a compromise between these points and taking into account water consumption. Usually, the volume of the tank is chosen in such a way that the humidifier can work quietly on a single refill for at least 2-3 hours, and often even more. Accordingly, the more capacious the tank, the more powerful and performant the device, as a rule. So, models with a volume of up to 2 litres belong to the entry-level, from 2 to 4 litres — to the average, from 4 to 6 litres — to the larger than average category, and in the most capacious devices this figure can exceed 6 litres .

Note that for models with the possibility of using a bottle (see below), this paragraph often indicates the optimal capacity of the bottle (such devices may not have their tanks).