Capacity
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.
Power consumption
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.
Recommended room area
A very conditional parameter that slightly characterizes the purpose by the size of the room. And depending on the height of the ceilings, layout, structure of the building and equipment, the actual values may differ significantly. Nevertheless, this item represents the maximum recommended area of the room that this model can effectively serve:
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.
Control via smartphone
The ability to remotely control the dehumidifier from a smartphone, tablet or similar gadget with a special application installed. The connection in this case is via
Wi-Fi.
This feature allows you to control the device from a distance and often gives you more options than the classic control method.
Air flow
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.
Dehumidifying operating range
The range of relative humidity (RH — relative humidity) of the ambient air, in which the dehumidifier is guaranteed to be able to cope with its task and at the same time perform at the level claimed by the manufacturer.
The wider this range — the more versatile the unit, the less likely it is to be in emergency conditions. At the same time, when choosing, it is worth considering the specifics of the application of the dehumidifier. Thus, dehumidifiers are initially designed for high humidity, but the ability to work at 100% relative humidity is not always required. For example, in the cold season, the air coming from the street is "drier" by itself when heated indoors (due to the increase in temperature, the relative humidity drops, although the actual amount of moisture in the air does not change), and even in wet weather, a dehumidifier with a limit of 80-90% may be enough. And the lower dehumidification limit directly depends on the tasks facing the device. If we are talking about living quarters, offices and other places where you need to create conditions that are pleasant for people, then you need to take into account that the most comfortable values for a person concerning humidity are 40-70%. Therefore, for such conditions, it makes no sense to specifically look for a device with a lower limit of less than 40%. But for specific tasks such as drying rooms during repairs, warehousing, etc. lower humidity levels may be needed.
Note that many model...s are quite capable of working outside the operating range, except that the performance may decrease. However, it does not hurt to clarify such an ability according to the official documentation.
Operating temperature range
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").
Noise level
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.
Child lock
As a rule, child lock means the ability to block device control 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.