Comparison Mitsubishi Electric Classic MSZ-HJ35VA/MUZ-HJ35VA 35 m² vs Mitsubishi Electric Design MSZ-EF35VEB/MUZ-EF35VE 35 m²

Power consumption of the air conditioner in cooling and heating mode; for models without a heating mode, only one number is given. This parameter should not be confused with the effective capacity of the air conditioner. Effective capacity is the amount of heat that the unit can "pump" into the environment or the room. This item also indicates the amount of electricity consumed by the device from the network.

In all air conditioners, the power consumption is several times lower than the effective capacity. It is due to the peculiarities of the operation of such units. At the same time, devices with the same efficiency may differ in power consumption. In such cases, the more economical models usually cost more, but with continued use, the difference can quickly pay off with less electricity consumption.

Also, two points related to electrical engineering depend on this nuance. Firstly, power consumption affects power requirements: models up to 3 – 3.5 kW can be connected to a regular outlet, while higher power consumption requires a three-phase connection (see below). Secondly, the power consumption is needed to calculate the load on the mains and the necessary parameters of additional equipment: stabilizers, emergency generators, uninterruptible power supplies, etc.

The heat output of the air conditioner when operating in cooling mode, in other words, the amount of heat energy that the unit can transfer from the room to the external environment when operating in this mode.

In general, cooling capacityup to 2 kW for modern air conditioners is considered very modest, 2–3 kW is low, 3–4 kW is medium, 4–6 kW is above average, and in the heaviest and most productive models this figure can be 6–8 kW and even more. Also, the conventional unit BTU can be used to denote capacity; in our catalogue, 1 BTU corresponds approximately to 0.293 W, however, for the convenience of choice, some deviations are allowed: for example, the 7000 BTU category includes units with power from 1.8 to 2.3 kW. Also on sale you can find air conditioners for 9000, 12000, 18000, 24000 BTU and more.

As for the choice for this indicator, the simplest formula is as follows: at least 100 W or 1/3 BTU of thermal power should fall on 1 m2 of the area of the room. Thus, to estimate the maximum area served, the power in watts should be divided by 100, and the power in...BTU should be multiplied by three. However, all these calculations are relevant only for standard residential/office premises with a ceiling height of about 2.5-3 m. For other conditions, you need to use a more complex formula, which is the sum of three parameters: 1) Q1 - the heat gain of the room itself, calculated by multiplying the area of the room by the height of the ceilings and the heat transfer coefficient (it ranges from 30 to 40 W, depending on the conditions); 2) Q2 - heat gain from operating equipment (on average, a third of the total power of all electrical appliances); 3) Q3 - heat gain from each person (from 100 W for sedentary work to 300 W for heavy physical exertion). More detailed recommendations regarding such calculations can be found in special sources.

A special case is represented by separately sold outdoor units of air conditioners (see "In box"). In this case, the capacity in cooling mode is the highest heating capacity of the indoor unit (in the same mode, of course) that can be connected to this outdoor unit. For multi split systems, respectively, the total indicator of all indoor units is taken into account.

The power provided by the air conditioner in heating mode. It is indicated by the amount of thermal energy that the air conditioner can "pump" from the external environment into the room when operating in this mode. The most modest modern units have a heating capacity of 2 – 3 kW or even less, in the most performant it reaches 6 – 8 kW or more.

When evaluating this capacity, the same formulas are relevant that are used in calculating the power of traditional heating. So, for the full heating of an ordinary residential or office space (with ceilings of 2.5-3 m and normal thermal insulation), a thermal power of at least 100 W is required. There are more detailed calculation rules that allow you to calculate the necessary characteristics for other conditions. And if we are talking about a separately sold outdoor unit (see "In box"), then the meaning of this parameter is somewhat different. It indicates the maximum power of the indoor unit that can be connected to this outdoor unit to work in heating mode. For multi split systems, respectively, the total capacity of all indoor units is taken into account.

Recall that most air conditioners are not designed for use as full-fledged heating systems. However, such a unit can be a good addition to the main heating system. At the same time, air conditioners are less expensive than el...ectric heaters: the heater has an effective power equal to energy consumption, and the air conditioner consumes much less energy than it supplies to the heated room.

Also note that the unit BTU (more precisely, BTU/hour) can also be used to indicate the effective capacity (including in heating mode). 1 BTU (BTU/h) initially corresponds to 0.293 W, and the numbers in the characteristics of air conditioners correspond to thousands of BTU/h. For example, a 7 BTU air conditioner will produce an effective capacity of 7000 BTU/h, or about 2 kW. Such marking is convenient because BTU can easily determine the recommended area of a standard room (in m2): just multiply the figure indicated in the characteristics by 3. So, in our example, the power of 7 BTU will correspond to an area of 7*3=21 m2.

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.

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.

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 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.

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.

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.