Air flow
The amount of air that an air conditioner can pass through itself in an hour.
This parameter depends on the power and the overall level of the device, but there is no strict dependence here: models with the same effective capacity may differ in air circulation speed. In such cases, it is worth proceeding from the fact that a higher speed contributes to uniform cooling/heating of the air and reduces the time required to create a given microclimate; on the other hand, higher-performing air conditioners use more energy, are larger and/or cost more.
Dehumidification
The rate at which moisture is removed from the air when the air conditioner is operating for dehumidification.
The amount of excess moisture that accumulates in the air depends on several parameters. There are special formulas and even calculator programmes that allow you to calculate this amount for a particular situation. These calculation methods can be found in special sources. It should also be said here that air conditioners are not full-fledged
dehumidifiers, so their performance in this mode is generally low.
Noise level (max/min)
The maximum and minimum level of noise produced by the air conditioner during operation; for split and multi split systems (see "Type"), by default, it is indicated for the indoor unit, and the data for the outdoor unit can be specified in the notes.
The noise level is indicated in decibels; this is a non-linear unit, so it is easiest to evaluate this parameter using comparative tables — they can be found in special sources. Here we note that, according to sanitary standards, the maximum level of constant noise for residential premises is 40 dB during the day and 30 dB at night; for offices, this figure is 50 dB, and in industrial premises higher volume levels may be allowed. So it is worth choosing an air conditioner according to this indicator, taking into account where and how it is planned to use it.
As for specific numbers, among the quietest modern air conditioners, there are models with a minimum performance of
23 – 24 dB,
22 – 21 dB, and sometimes even
20 dB or less. However, units at
31 – 31 dB and
33 – 34 dB are not uncommon; such loudness, usually, does not create discomfort in the daytime, but at night it is no longer desirable. However, in some cases, a louder air conditioner may be the best choice: noise reduction affects the cost, sometimes quite noticeably, and if the device
...is not planned to be turned on at night, you can not overpay for additional noise reduction.Cooling EER
Cooling factor EER provided by the air conditioner. It is calculated as the ratio of the useful operating power of the air conditioner in cooling mode to the electricity consumption. For example, a device that delivers 6 kW of operating power in cooling mode and consumes 2 kW will have an EER 6/2 = 3.
The higher this indicator, the more economical the air conditioner is and the higher its cooling energy efficiency class (see below). Each class has its clear requirements for EER.
It is worth noting that this indicator is considered not very reliable, and in the European Union another coefficient has been introduced that is closer to practice — SEER. See Energy efficiency SEER (cooling) for more details.
Heating COP
The heating coefficient COP provided by the air conditioner. It is calculated as the ratio of the heat output of the air conditioner in heating mode to the electricity consumption. For example, if a device consumes 2 kW and produces 5 kW of thermal power, then the COP will be 5/2 = 2.5.
The higher this indicator, the more economical the air conditioner is and the higher its energy efficiency class when heating (see below). Each class has its own clear COP requirements.
Note that COP values are usually higher than the values of another important coefficient — EER (see above). It is due to the technical features of the air conditioners.
It is also worth mentioning that since 2013, a more advanced and closer-to-practice coefficient, SCOP, has been put into use in Europe. See "Energy efficiency SCOP (heating)" for more details.
Energy efficiency EER (cooling)
The general energy efficiency class that the air conditioner complies with in cooling mode.
This parameter is indicated by letters from A (highest efficiency) and beyond. It is directly related to the value of the EER factor (see "Cooling EER"): each energy efficiency class corresponds to a certain range of factors (for example, B — from 3.0 to 3.2). Specific coefficient values for each class can be found in special tables; here we note that more efficient air conditioners are more expensive, but this difference can pay off due to less electricity consumption.
Energy efficiency COP (heating)
The general energy efficiency class that the air conditioner corresponds to when operating in heating.
This parameter is indicated by letters from A (highest efficiency) and beyond. It is directly related to the value of the COP coefficient (see "Heating COP"): each energy efficiency class corresponds to a certain range of coefficients (for example, C — from 3.2 to 3.4). Specific coefficient values for each class can be found in special tables; here we note that more efficient air conditioners are more expensive, but this difference can pay off due to less electricity consumption.
Display
A small screen installed on the indoor unit of the air conditioner. Such
a display usually has basic functionality and displays a limited set of characters - numbers, some letters, sometimes also individual graphic icons. However, even such a screen can display quite a variety of information: set temperature, operating mode, timer settings, filter status, error codes, etc. Thanks to this, control is more convenient and visual.
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Hidden display. When switched off, the hidden info display blends in with the surface design of the indoor unit of the air conditioner and remains invisible. In active mode, the characters on the screen are visible through a certain place in the texture and all the necessary information is displayed on the display. On most models, the screen can be turned off using the remote control, and this feature can often be set to automatically hide after a certain period of inactivity, which will be useful at night.
Maximum height difference between units
The maximum height difference allowed for split system units. For multi splits (see "Type"), in this case, we mean the difference in height between the highest and lowest unit.
When installing units at different heights, a pressure difference arises in the system — the greater the height difference, the greater this difference, and if it is too large, the system will not be able to work normally.
