Recommended room area
The area of the room recommended for using the air conditioner in the main mode is for cooling.
Most often, this parameter is indicated by a simplified formula: about 100 W of effective air conditioner power is required per 1 m2 of room area. Thus, for example, for a model with a cooling capacity of 2200 W, the recommended area will be 2200/100=22 m2. However, these results are relevant only for standard conditions in residential and office premises: ceiling height of about 2.5-3 m, no strong heat gain, etc. For more specific situations, there are more detailed calculation formulas, that can be found in special sources. Anyway, choosing an air conditioner according to the recommended area, it's ok to take a margin of at least 15-20%: this will give an additional guarantee that the device will be effective.
The recommended area
up to 15 m2 for a modern air conditioner is considered very low; such units are designed to serve single rooms of a small area. For an average living room like a bedroom or living room, a
20 m2 or even
25 m2 model is better suited. Models of
30 m2 and above are already intended for at least studio apartments, and more often for office and industrial premises. And in the most powerful modern units, the recommended area can be
150 – 175 m2 or even
more.
Note that the same general formula is used for the heating mode — “100 W per 1 m2”. At the same time, the effective power of most air conditioners in this mode is noticeably higher than in the cooling mode. So this item can also be used to select a unit with a heating function: an air conditioner capable of cooling a room of a certain area is almost guaranteed to be able to heat it (taking into account the relevant restrictions on the use — see "Operating modes").
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.
Seasonal cooling SEER
The seasonal SEER cooling factor provided by the air conditioner.
The meaning of this parameter is similar to the cooling coefficient — EER (see above): we are talking about the ratio of useful power to spend, and the higher the coefficient, the more efficient the device is. The difference between these parameters lies in the measurement method: EER is measured for strictly standard conditions (outside temperature +35 °C, workload 100%), while SEER is closer to reality — it takes into account seasonal temperature fluctuations (for Europe) and some other specific points, such as the increased efficiency of inverter compressors. Therefore, since 2013, it is customary to use SEER as the main parameter in the EU; this parameter was also adopted for air conditioners supplied to other countries with a similar climate.
Seasonal heating SCOP
Seasonal heating coefficient SCOP provided by the air conditioner.
Like the COP (see above), this parameter describes the overall efficiency of the air conditioner in heating operation and is calculated by the formula: thermal (useful) power divided by electricity consumption. The higher the coefficient, the more efficient the device, respectively. And the difference between COP and SCOP is that COP is measured under strictly standard conditions (outside temperature +7 °C, full workload), and SCOP takes into account seasonal temperature fluctuations (for Europe), changes in air conditioner operating modes, the presence of an inverter and some other options. Thanks to this, SCOP is closer to real indicators, and since 2013 this coefficient has been taken as the main one in the territory of the European Union. However, this parameter is also used for air conditioners supplied to other countries with a similar climate.
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.