Power consumption (cooling/heating)
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.
Cooling capacity
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 capacity
up 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.Heating capacity
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.Air flow
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.
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.Refrigerant type
The type of refrigerant used in the air conditioner.
The refrigerant is a volatile liquid that transfers heat between the outdoor unit(s) and the indoor unit(s). In common parlance, such compounds are also called freons, although this is not entirely technically correct. The type of refrigerant is most important when buying air conditioner units separately — for example, to assemble a multi split system (see "Type"): all units must use the same type of freon, otherwise they will be incompatible. However, there are quite noticeable physical differences between different compositions, sometimes quite important.
The most common refrigerants nowadays are
R22,
R32,
R407C,
R410A, R134A and R290, here is a more detailed description of them:
— R22. The "oldest" of the varieties of refrigerant found nowadays. It is distinguished by its low cost, and low operating pressure (which has a positive effect on the reliability and price of the cooling circuits themselves). And uniform composition, which makes it possible not to change it entirely in case of a refrigerant leak, but simply replenish the system with the required amount of liquid. However, R22 is environmentally unsafe (mainly for the ozone layer), which is why nowadays it is gradually being replaced by more advanced compounds.
— R32. A fairly advanced refri
...gerant that combines three key advantages: efficiency, environmental friendliness and uniformity. So, air conditioners under R32 can be made quite compact and, at the same time, powerful; this substance does not destroy the ozone layer and does not have a significant effect on global warming; and a homogeneous composition allows you to refuel the air conditioner without problems in case of a leak. The main disadvantage of models with this type of refrigerant is the high price associated not so much with the cost of the R32 itself but with the specific requirements for the design of the refrigeration circuit.
— R407C. A refrigerant designed as a safe alternative to R22; does not affect the ozone layer. At the same time, such a composition is much more expensive; its working pressure is slightly higher, which requires a greater strength of the cooling circuit (although not as high as for R410A); and polyester oil used with R407C tends to absorb moisture and lose properties. In addition, this filler is zeotropic (heterogeneous in composition): its components have different boiling points and different evaporation rates. As a result, even with a small leak, the refrigerant loses its properties, and the situation can be corrected only by a complete refilling of the air conditioner.
— R410A. Another green alternative to R22. Unlike R407C, it is azeotropic — it consists of components with the same evaporation specs; so in the event of a leak, the ratio of these components does not change, in which case refilling the circuit is allowed instead of completely replacing the contents. On the other hand, R410A is characterized by high operating pressure, which puts serious demands on the strength and reliability of the cooling circuit and increases its cost; and the refrigerant itself is quite expensive.
— R134A. One of the modern refrigerants with advanced properties. It is completely homogeneous, like R22, but at the same time, it is safe for the ozone layer and is characterized by a low coefficient of influence on global warming. The disadvantage of this composition is traditional — high cost; in addition, it uses polyester oil, which is prone to moisture absorption.
— R290. Liquefied propane is used as a refrigerant. It has several advantages: non-toxic, environmentally friendly (zero impact on the ozone layer, minimal impact on global warming), homogeneous (i.e. does not require complete replacement in case of leakage, it is enough to replenish the missing amount), used with mineral oil, which is insensitive to moisture. In addition, propane has a low operating pressure, which simplifies the design of circuits and reduces their cost, as well as a low temperature at the outlet of the compressor, which contributes to efficiency. This refrigerant has two disadvantages: flammability and high compressor power requirements, which makes such units quite heavy and bulky. Therefore, despite all the advantages, R290 is used quite rarely.Indoor unit dimensions (WxHxD)
Dimensions of the indoor unit of the air conditioner in height, width and depth.
These dimensions allow you to estimate how much space you need to place the device. In this case, of particular importance — mainly for split and multi split systems with wall mounting is the width of the indoor unit. The fact is that in terms of the height and depth of the internal blocks, most of these systems differ slightly in general but the differences in width are much more noticeable. So, the narrowest models have a width of
76 – 80 cm or
less, and the largest ones occupy
91 – 95 cm, and often
more. At the same time, the more powerful the air conditioner, the wider it is, usually, but there is no rigid dependence here.