Comparison Midea MDDG-30DEN1 vs Midea MDDF-16DEN7

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 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.

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.

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.

The type of refrigerant used in the dehumidifier.

A refrigerant is a special substance (most often freon), which circulates through the cooling circuit in dehumidifiers with a condensing principle of operation (and these are all varieties, except for adsorption ones — see "Suitable for"). This substance provides the removal of excess heat generated during condensation of moisture. The type of refrigerant primarily determines the technical features of its application, such as the possibility of partial replacement and the requirements for the strength of the cooling circuit.

In modern dryers, you can mainly find brands of refrigerants such as R22, R407C, R410A, R134A, R290 and R32. Here is their general description:

— R22. The most "old" of the varieties of refrigerant found nowadays. It is distinguished by low cost, low operating pressure (which has a positive effect on the reliability and price of the cooling circuits themselves) and uniformity of composition, which allows, in case of a refrigerant leak, not to change it entirely, but simply to replenish the system with the required amount of liquid. However, R22 is environmentally unsafe (mainly for the ozone layer), which is why it is gradually being replaced by more advanced compounds.<...br>
— R32. A fairly advanced refrigerant that combines three key advantages: efficiency, environmental friendliness and uniformity. Dehumidifiers with R32 can be made quite compact and, at the same time, performant; this substance does not destroy the ozone layer and does not have a significant effect on global warming. The main disadvantage of models with this type of refrigerant is the high price.

— R407C. A refrigerant designed as a safe alternative to R22; does not affect the ozone layer. At the same time, such a composition is much more expensive; its working pressure is slightly higher, which requires a greater strength of the cooling circuit (although not as high as for R410A); and polyester oil used with R407C tends to absorb moisture and lose properties. In addition, this refrigerant is zeotropic (heterogeneous in composition): its components have different boiling points and evaporation rates. As a result, even with a small leak, the composition of the refrigerant and its properties change, and the situation can be corrected only by a complete replacement of freon.

— R410A. Another "green" alternative to R22. Unlike R407C, it is azeotropic — it consists of components with the same evaporation characteristics; so that in the event of a leak, the ratio of these components does not change, in which case refilling of the circuit is allowed instead of a complete replacement of freon. On the other hand, R410A is characterized by high operating pressure, which puts serious demands on the strength and reliability of the cooling circuit and increases its cost; and the refrigerant itself is quite expensive.

— R454C. Hydrofilin-based refrigerant is considered environmentally friendly and environmentally friendly, positioned as another option to replace the outdated R22 and an alternative to R407C. The composition is a mixture of R32 and R1234YF.

— R134A. One of the modern freons with advanced properties. It is completely homogeneous, like R22, but at the same time, it is safe for the ozone layer and is characterized by a low coefficient of influence on global warming. The disadvantage of this refrigerant is its traditional — high cost; in addition, it uses polyester oil, which is prone to moisture absorption.

— R290. Liquefied propane is used as a refrigerant. It has several advantages: non-toxic, environmentally friendly (zero impact on the ozone layer, minimal impact on global warming), homogeneous (i.e. does not require complete replacement in case of leakage, it is enough to replenish the missing amount), used with mineral oil, which is insensitive to moisture. In addition, propane has a low operating pressure, which simplifies the design of circuits and reduces their cost, as well as a low temperature at the outlet of the compressor, which contributes to efficiency. This refrigerant has two disadvantages: flammability and high compressor power requirements, which makes such units quite heavy and bulky. Therefore, despite all the advantages, R290 is used relatively rarely.

The presence of wheels in the dehumidifier, facilitating movement from place to place.

It makes sense to use such equipment only in models with the option of floor placement (see "Installation"). In different models, the wheels may have a different design, but they significantly facilitate transportation: with the help of one person, even a rather weighty unit can be rolled. It is especially true because modern dehumidifiers are quite heavy — even in the most compact devices it is about 8-10 kg.