Nominal capacity BTU
The British Thermal Unit (BTU) is used to indicate the rated capacity of air conditioners in cooling mode. The parameter is indicated mainly for split and multi split systems with wall installation. Capacity is indicated in BTU per hour, while 1 BTU/h is equal to about 0.293 watts. The rated capacity of an air conditioner is often a multiple of 1000 BTU. The indicator determines how many thousand BTU/h the air conditioning equipment provides. For example, the marking "9 BTU" here means a unit for 9000 BTU/h or about 2600 watts of effective capacity.
The practical meaning
of the capacity is that by BTU you can easily determine the recommended area of a standard room in square meters: just multiply the figure indicated in the characteristics by 3. So, for 9 BTU it will correspond to 9*3=27 m². Note that there is no strict relationship between BTU and watts in this list: for example, air conditioners with an effective capacity of 2360 to 2900 W fall into the same category of 9 BTU. In practice, even such an approximate ratio is enough to understand which air conditioner should be considered for cooling certain area.
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.
Energy efficiency SEER (cooling)
The seasonal energy efficiency class that the air conditioner complies with in cooling operation. 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 parameter is directly related to the value of the SEER coefficient. For more information on this factor and how it differs from the EER, see "Seasonal Cooling SEER Ratio". Here we note that each class has its range of SEER values; detailed correspondence 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 electicity.
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.
