Comparison Philips HU4813 vs Philips HU4803

The area of the room for which the device is designed. This parameter indicates the maximum area in the 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 a higher ceiling height, the effective humidification space decreases, and it can be recalculated using special formulas.

When choosing by area, it is worth taking a certain margin, but it should not be too large — otherwise, the device will turn out to be unnecessarily 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.

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 noise level generated by the air cleaner when operating in low or night mode. Most of these devices are used in domestic conditions, so the noise level plays an important role, especially at night. According to sanitary standards, constant noise in such rooms should not exceed 40 dB (quiet conversation) during the day and 30 dB (wall clock ticking) at night. More detailed comparison tables and recommendations can be found in special sources.

The noise level generated by the air purifier during operation. Most of these devices are used in residential areas, so this parameter should be treated carefully. According to sanitary standards, constant noise in such rooms should not exceed 40 dB (quiet conversation) during the day and 30 dB (wall clock ticking) at night. More detailed comparison tables and recommendations can be found in special sources. It is also worth mentioning that the noise level is indicated for the maximum operating speed, so the noise level will be significantly lower in reduced mode.