Modes and programs
Cooling and ventilation modes are in each model by definition. But air conditioners with
humidification are relatively rare. For them, the opposite format is mandatory — dehumidification and
heating.
- Cooling. The mode of lowering the air temperature in the room is the main function of any air conditioner. Note that conventional air conditioners, when cooled, also remove moisture from the air. However, due to a decrease in temperature, the relative humidity in this mode changes slightly (or does not change at all).
- Ventilation. The mode in which the air conditioner provides only air circulation throughout the room, without changing its temperature and humidity. Such a function can be useful, for example, for air mixing and temperature equalization; in addition, when passing through the air conditioner, the air is filtered, which is useful, for example, for cleaning from dust and smoke, or for ensuring hygiene in a room where a sick person is. Let us emphasize that ventilation must be distinguished from the
fresh air intake(see "Functions"). The ability to add air from outside is rare and only in expensive models of air conditioners.
- Dehumidification. Mode for removing excess moisture from the air. This function works by condensing water vapour on the cold heat exchanger of the air conditioner; the collected mo
...isture is usually removed to the outside through a drainage tube or accumulates in a special reservoir. Note that condensation also occurs in the cooling mode (see above); the dehumidification mode differs from it in that the temperature of the air passed through the air conditioner changes very slightly — usually by no more than 1 °C — but the humidity drops very noticeably.
— Heating. The mode of increasing the air temperature in the room. It should be borne in mind that most air conditioners with this function are not designed to be used as full-fledged heating systems - their task is to "help" such systems, as well as heating in the off-season, when the main heating does not work. In addition, the permissible outside temperature (see “Minimum t for heating mode”) can be different: for example, not every unit with a heating mode can work in cold weather. On the other hand, there are exceptions - powerful cold-resistant models, approaching the characteristics of heat pumps and withstanding temperatures of -25 ° C and even lower.
- Humidification. A need to increase air humidity often arises in winter. When the air is heated by heating devices, its relative humidity decreases (and the overall comfort in the room is associated precisely with relative humidity). In addition, in rooms where there are small children, it is recommended to specially humidify the air. The humidifying mode in air conditioners is rare and only in premium models. And for the operation of the humidifier, a supply of water is required, which must be monitored and periodically replenished.
— Fresh air intake. Ability to mix fresh air from outside with the air passed through the conditioner. Thus, models with this function not only change the temperature and humidity of the air but also additionally refresh it. On the other hand, mixing significantly complicates both the design of the air conditioner itself and its installation. Therefore, this function is rare, and mainly in models of the middle level and above.
— Automode. A function that relieves the user of the need to manually control the parameters of the air conditioner. It is enough just to set the desired microclimate in the room. After that, the unit will independently monitor the current conditions and select the desired operating mode. Most often, this function provides temperature monitoring and automatic switching between cooling and heating but advanced models may provide more advanced features, such as humidity monitoring with automatic dehumidification or even humidification.
— Night mode. A function that allows you to use the air conditioner as comfortably as possible at night. There are two main features of this mode. First, the fan speed is set to a minimum, which reduces noise and avoids strong air currents that can disturb sleepers. Secondly, the temperature change occurs very slowly and smoothly — by a couple of degrees within two to three hours; this is considered optimal for sleep. Additionally, in the night mode, a timer can be provided that turns off the air conditioner after 7-8 hours.
— Emergency heating. A function found in air conditioners with heating (see "Operating modes"); is intended mainly for summer cottages and other similar places that can be left unattended for a long time during the cold season. When using standby heating, the air conditioner maintains a low positive temperature in the room (about +8..10 °С). It is enough to avoid freezing of walls and damage to communications, and at the same time, energy consumption is low.
— Self-cleaning. The mode of automatic cleaning of the internal parts of the air conditioner — usually due to intensive purging with air. It allows you to remove the accumulated dust inside and dry out excess moisture and also prevents the growth of harmful microorganisms. At the same time, self-cleaning does not eliminate the need for full manual cleaning or replacement of working elements in the air conditioner filters. Noise level (outdoor unit)
The maximum noise level in decibels (dB) produced by the outdoor (outdoor) air conditioner unit during normal operation.
In household split systems, the noise level from the external unit is usually in the range from 40 to 55 dB. The lower this indicator, the quieter the unit operates and the more comfortable it is to use. Sanitary standards require the noise level for residential buildings from permanent sources to be no higher than 40 dB during the day and 30 dB at night, and in offices background noise of up to 60 dB is completely acceptable. The easiest way to estimate specific noise levels is using comparative tables. So, 40 dB is the level of a quiet conversation or TV at medium volume, 50 dB is approximately the normal tone of human speech, and 60 dB is the level of a loud voice. More detailed data can be found in special sources.
It is important to note that indoors the background noise level from the outdoor unit will be significantly less than outdoors. However, if the noise does not bother you when the air conditioner is running, this does not mean that it does not bother your neighbors. With open windows, the external unit can become a fairly strong source of noise. Therefore, for apartment housing stock it is advisable to give preference
to low-noise models of climate control equipment.
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 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.
Energy efficiency SCOP (heating)
The seasonal energy efficiency class that the air conditioner complies with when operating for heating. Initially, this parameter was designated in letters from
A(the most economical indicator) to G (the most expensive); however, more efficient classes than A appeared later —
A+,
A++ and
A+++(the more pluses, the higher the energy efficiency).
This indicator is directly related to the value of the SCOP coefficient. For more information about this coefficient and how it differs from the COP, see "Seasonal heating SCOP". Here we note that each class has its range of SCOP values; detailed tables can be found in special sources.
Other things being equal, more energy-efficient air conditioners are more expensive, but the difference can be recouped as it uses less electricity.
Compressor
The brand of the compressor installed in the air conditioner.
The compressor is the "heart" of the unit, it is on its specs that the capabilities of the air conditioner and the features of its operation primarily depend. And the brand of this part is specified mainly in cases where an advanced compressor is used in the design, which is noticeably superior to conventional options in terms of specs and overall quality. So this parameter is more advertising than practically significant. However, if you wish, you can find data on the general features and "reputation" of a particular brand and use this information for the final choice.
Note that even in air conditioners of the same brand, different brands of compressors can be used. It is because many manufacturers of such parts do not produce ready-made air conditioners, but only sell components to third-party companies. However, there are exceptions — usually large corporations such as Panasonic or Mitsubishi Heavy, or top manufacturers like Daikin.