Comparison Ballu BDH-40L vs Ballu BDH-25L

The general scope of the dehumidifier and the associated design and functional features depend on the purpose.

— Home. Usually, these are relatively compact devices, many of which are designed for ease of movement from place to place, within the same apartment, office, etc. (although there are models with wall mounting, see below). The performance of most home dehumidifiers is relatively small, but for the purposes for which they are used (air dehumidification in residential areas), this is quite enough. Such models have a fairly neat design, which allows them to successfully fit into the overall design of the premises mentioned.

— Pool. A specialized type of dehumidifier designed for use in indoor swimming pools, where it is necessary to constantly work with large volumes of air with high humidity. However, the performance of dehumidifiers of this type can be different — after all, pools can have different sizes. But the system of permanent condensate drainage(see "Features") is mandatory for all such units — this is due to the specifics of the work (because the water from the surface of the pool evaporates constantly). The difference between such dehumidifiers and the ducted systems described below is that they are installed directly in the pool room.

— Professional. A type of dehumidifier designed primarily for use in industrial faciliti...es, utility rooms, etc. All professional models are distinguished by two key features. The first one is rather high performance. Of course, there are exceptions, but they are rare. Secondly, in professional dehumidifiers, minimal attention is paid to appearance. It is because such devices are supposed to be used in non-residential premises, where the key role is played exclusively by the functionality of the equipment, and its aesthetics is not important.

— Ducted. Specific types of dehumidifiers are used for swimming pool areas. From models for the pool (see above), this variety differs primarily in that the ducted unit is installed in a separate room, where duct pipes are supplied from the main room. Thus, the dehumidifier does not affect the design of the room; in addition, such an installation allows the use of very powerful and performant (and, accordingly, large-sized) units, which far exceed the capabilities of conventional dehumidifiers, but are of little use for installation in the same room. Ducted models are designed mainly for public swimming pools, water parks and other large spaces.

The nominal capacity of the dehumidifier is the maximum amount of moisture that the unit can remove from the air per day.

For efficient operation, the capacity of the dehumidifier must be no less than the amount of excess moisture that accumulates in the room during the same time. This amount can be calculated using special formulas or calculator programs. However, the results of such calculations are quite approximate, but they can be used in the selection, and for a full guarantee it is worth taking a performance margin of at least 10–20%. If desired, this margin can be more; but note that high performance significantly affects the price, dimensions and energy consumption of the dehumidifier.

As for specific values, entry-level models for small spaces provide less than 25 L/day. Indicators of 26 – 50 L/day can be called average, 51 – 75 L/day — above average; there are also many powerful professional units with a capacity of more than 75 L/day.

Power consumption of the dehumidifier in normal operation.

From a practical point of view, this characteristic is secondary — manufacturers select power in such a way as to provide the necessary operating parameters (performance, air flow, etc.), and when choosing, you should focus primarily on these parameters. However, certain practical points also depend on the power consumption. Firstly, only models of less than 3-3.5 kW can be connected to ordinary household outlets; higher power consumption will require either a 400 V supply (see Power supply) or a direct connection to the panel. However, even power of more than 2 kW is rare in modern dehumidifiers — for most of these devices, the energy consumption is in the range from 500 to 1000 W or from 1000 to 2000 W, and in the most modest models it does not exceed 500 W at all. Secondly, power data may be required to calculate the load on the power grid. Such a need arises mainly for the selection of additional equipment — circuit breakers, AVR, UPS, etc.

Also, note that models with similar performance may differ in power consumption. However, a more economical dehumidifier often costs more, but with regular use, this difference pays off by reducing energy costs.

The area of the room for which the device is designed. It is the maximum area that this model can effectively handle: the use in smaller rooms is quite acceptable, but the device simply does not have enough performance for a larger space. Also, note that the area is indicated based on a ceiling height of 2.5-3 m — the standard value for residential premises; with a higher ceiling height, the effective area 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 be unnecessarily powerful, bulky and expensive.

The type of control provided in the design of the dehumidifier.

The type of control determines how external control elements (buttons, knobs, sliders) interact with the hardware of the unit. There are two options here:

— Mechanical. Systems in which the control elements act directly on the individual parts of the dryer. For example, fan speed adjustment (see "Features") in such systems can be carried out using a slider that directly changes the resistance of the resistor in the fan power circuit; the shutdown timer (see ibid.) is a rotary knob with a clock mechanism, etc. The mechanical control is simple and reliable, it is suitable for all basic functions of the dehumidifier and at the same time, it is inexpensive. On the other hand, such systems are inferior in accuracy to electronic ones, and besides, they do not allow many additional features (remote control, display, etc.). Therefore, although this type of control can be found in all categories of dehumidifiers, there are fewer such models on the modern market than electronic ones.

— Electronic. Control is carried out through a special electronic circuit: each user action (pressing a button, turning a knob, etc.) is processed by this circuit, and from it control signals are sent to the working elements of the dehumidifier. Such systems are more functional and advanced than mechanical ones. Electronic control is conveni...ent and allows you to use various additional functions — for example, displays and remote controls; and individual parameters can be controlled with very high precision and small adjustment steps. The disadvantages of electronic systems are considered to be higher cost and lower reliability than mechanics, as well as repair difficulty. At the same time, these shortcomings are not so often critical: for example, differences in cost are usually almost imperceptible against the the overall price of devices, and the probability of failure in modern electronics is still very low. Nowadays, it is the most popular type of control among dehumidifiers of all categories. And it can be implemented either by buttons or by touch panel. The second option gives the device a solid look.

The maximum amount of air that a dehumidifier can pass through in an hour.

The choice for this parameter depends on the size of the room. It is believed that for effective operation, the dehumidifier must drive through itself an amount of air in an hour that exceeds the volume of the room by 3-4 times; and you can determine the volume of the room by multiplying the area by the height of the ceiling. For example, a 12 m² room with 2.5 m ceilings will hold 12*2.5=30 m³ of air; accordingly, for efficient operation in such a room, a dehumidifier with a capacity of 30*3=90 m³/h, and preferably 30*4=120 m³/h, is required. It is quite possible to choose a unit with a margin for airflow — unless you need to take into account that an increase in performance affects the price and energy consumption. But a too-low value of this parameter is undesirable: such a dehumidifier simply cannot effectively cope with its task.

As for specific figures, relatively low-power models produce up to 250 m³/h, equipment for 251–500 m³/h and 501–750 m³/h can be attributed to the average level, and many units are capable of processing more than 750 m³/h.

The ambient temperature range in which the dehumidifier can operate normally. The wider this range, the more versatile the dehumidifier is, and the more diverse the conditions in which it can be used. Note that, in contrast to the humidity range (see above), going beyond the operating temperatures is fraught not only with loss of efficiency but also with serious malfunctions and even breakdowns. Therefore, it is worth choosing a unit according to this parameter in such a way that it is guaranteed to block possible fluctuations in the temperature of the air with which the dehumidifier is to work.

Note that most modern models are designed to operate at positive temperatures, with the lower limit being on average about 4–5 °C. The only type of dehumidifiers that can operate at temperatures below zero are adsorption dryers(see "Suitable for").

The volume of the tank for collecting condensate (moisture removed from the air), provided in the design of the dehumidifier.

The larger the condensate tank, the slower it will fill up and the less often it will have to be emptied. It is especially important for high-performance units (see above). On the other hand, the volumetric tank has the appropriate dimensions, which affects the dimensions of the entire dryer. When evaluating the relationship between tank capacity and dehumidifier performance, note that the device rarely operates at full capacity. See "Dehumidification capacity" for more on this; here we note that if, for example, a dehumidifier with parameter of 24 L/day has a tank of 4 litres, this does not mean that the tank will necessarily be filled to the top every 4 hours. An alternative to tanks is the use of permanent condensate drainage systems; see "Features" for details.

The maximum noise level produced by the dryer during operation. The lower this number, the more comfortable the use of the unit will be; this is especially true for residential premises. For workshops, warehouses and other similar places, the noise level is not so critical — this type of climate control equipment is often installed in places where there are almost no people, or in the vicinity of such noisy equipment, against which the noise from the dehumidifier can simply be lost. However, for non-residential premises, data on the noise can be useful — for example, to assess the need for special ear protection and other labour protection measures.

Note that this parameter is measured in decibels, and this is a non-linear value: for example, a change of 3 dB approximately corresponds to an increase/decrease in power by 2 times, by 10 dB — by 10 times, etc. Therefore, to assess the noise level, it is easiest to use comparative tables. Here is a simplified table for the range that most modern dehumidifiers fall into.

35 dB — muffled conversation;
40 dB — quiet conversation; the maximum noise level allowed in residential premises during the daytime;
45 — 50 dB — conversation in a normal tone;
55 dB — background sound in the office without special noise sources;
60 dB — loud conversation;
65 dB — city street with average traffic intensity;
70 dB — a conversation of several people in raised tones.