Comparison Mitsubishi Electric Premium Zubadan MSZ-LN35VG/MUZ-LN35VGHZ 35 m² vs Fujitsu ASYG12KGTB/AOYG12KGCA 34 m²

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").

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 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 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.

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 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.

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.

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.