There are several important criteria that must be taken into account when choosing an air conditioner. The first step is to decide on the type of air conditioning equipment and how it is installed.

Types of air conditioners and installation options

The most versatile variety of air conditioners are split systems. This is the most common option for an apartment, private house or office. Structurally, split systems consist of an outdoor unit mounted on the facade of the building, and an indoor one, which is usually mounted on the wall in the room. Between themselves, the units are connected by a pipeline through which the refrigerant (freon) circulates. The outdoor unit is the most noisy and big part of the device. It provides heat exchange with the outside, while the indoor unit is responsible for direct air conditioning.

In multi split systems, there are several indoor units for one outdoor unit. Such models are suitable for air conditioning several rooms at once or one large room (provided that the indoor units are located in different zones of the serviced area). Installation of such a system is easier, and the cost is cheaper than using separate split systems. It is also worth noting that multi splits systems are often sold in separate blocks, rather than ready-made sets, which makes it easier to select the components of such a system for a specific situation.

In multi split systems, one outdoor unit usually has several indoor units.

Portable air conditioners are suitable for summer cottages or rented apartments. They are supposed to be used in situations where it is not possible to install a stationary split system. Portable devices have a monoblock design and are placed on the floor. For ease of movement, transportation wheels are usually attached to the body of portable air conditioners. Most of these air conditioners are designed for an area of no more than 20 – 30 m². In addition, floor-standing devices are not characterized by quiet operation and water must be regularly poured out of them, which condenses in a special compartment.

Split Systems

The format of operation of portable air conditioners is slightly different from traditional split systems: they divide the air passed through them into two parts, one of which is cooled and the other is heated. In cooling mode, cool air is returned to the room, and warm air is expelled through the air duct to the outside. When operating on heating, everything happens exactly the opposite. The most time-consuming task when installing a portable air conditioner is the need to bring the corrugated pipe out of a window (or an opening in a wall). It is important that the gaps between it and the window glass are minimal or there are none at all. Only in this case will the proper effect of cooling or heating the room be ensured.

A design feature of portable air conditioners is the need to bring a corrugated pipe outside to remove hot air.

By the installation methods of the indoor unit, air conditioners are as follows:

Wall

Household split systems are traditionally made wall-mounted. Air conditioning equipment with this installation option is the most widely used. The indoor unit of the air conditioner is usually mounted on a wall with a gap from the ceiling at a distance of at least 10 – 15 cm – the gap is needed for efficient air intake and correct operation of air conditioning equipment. Wall mounting is quite simple from a technical point of view, while it provides extensive opportunities for choosing the installation place, and the air conditioner itself takes up a minimum of space in the room.

Wall Air Conditioners

Ceiling (cassette)

The indoor unit of cassette air conditioners is mounted in the interceiling space (between the main and decorative ceilings). It is advisable to buy them for servicing large areas (from 50 m²). This is an option for cottages, large living rooms, spacious offices, conference rooms. In most models, the indoor unit has a characteristic square shape, and the air flows from it are directed almost horizontally in all four directions. That is why the indoor unit is usually placed in the center of the ceiling.

Ducted

For ducted air conditioners, the indoor unit is installed behind a false ceiling or built into the upper part of the wall. Air flow is circulated through ducts and grilles. Moreover, through the air duct system, conditioned air can be directed to several rooms at once – one indoor unit can serve different rooms (for example, offices in an office building). However, the adjustment of the microclimate parameters will be carried out simultaneously for the entire area, usually, without the possibility of flexible temperature settings for individual rooms. The features of these systems are the inconspicuous installation of the indoor unit and the uniform distribution of air masses around the perimeter of the serviced premises.

The picture shows the following types of air conditioners according to the installation method: 1 – wall, 2 – cassette, 3 – floor-ceiling, 4 – ducted, 5 – column, 6 – floor, 7 – window, 8 – portable.

Column

In appearance, such air conditioners resemble a large column, which is installed on the floor. In fact, that's where their name came from. According to the principle of operation, column models are similar to traditional split systems. However, their key character trait is the ability to create a powerful stream of air that can quickly cool or heat quite large spaces. Column devices are very bulky. Their use is advisable in large spacious rooms: gyms, shopping malls, lobbies of private clinics, large rooms in a country house.

Floor and floor-ceiling

This category includes both relatively low-power air conditioners designed for floor installation with wall mounting, as well as powerful air conditioning equipment that allows several installation options. Floor-ceiling models can be mounted on the floor against a wall – with this installation, the airflow from their indoor unit is usually directed upwards, which minimizes the likelihood of drafts. On the ceiling, such air conditioners are placed horizontally. The cooled air is also distributed in a corresponding way, thereby maintaining a more uniform temperature in the served room.

Window

A once popular installation option, which is now almost never found. Such products consist of one block, in which all the necessary functions are combined. This monoblock is installed directly into the window opening. Window air conditioners are inexpensive, but inconvenient to install and use, which is why they have almost gone out of wide use.

Helpful advice. Our article "The main rules for choosing a place for an air conditioner in an apartment" will help you decide on the most suitable place for air conditioning equipment.

Choosing an air conditioner according to the size of the room

Having decided on the type of air conditioner, it is extremely important to choose the right model by power. The main issues here are the area of the serviced premises and the height of the ceilings. How comfortable it will be in the room and whether the device can consistently cope with tasks depends on the correct selection of power. The lack of power will force the air conditioning equipment to operate constantly, which increases electricity consumption and leads to premature failure of the equipment.

With a standard ceiling height of about 2.7-2.8 m, for every 10 m² of area there should be at least 1 kW of power. Approximate power options for other ceiling heights are shown in a picture:

Table for selecting an air conditioner by power, depending on the area of the room and the height of the ceilings.

If the windows of the room face the sunny side, it is advisable to add another 20 - 30% of the power. Also, a small power reserve will be required for rooms with lots of electrical appliances, computer equipment and people – they all emit excess heat and in such conditions the air conditioner is not doing its job of cooling well.

In order not to be engaged in calculations of the required power for a certain number of square meters, the catalog provides convenient filters for selecting air conditioners according to the size of ​​the room.

The power of the air conditioner can be indicated not only in kilowatts, but also in British thermal units BTU. Usually, this value is typical for wall split and multi split systems. The effective power of air conditioning equipment is indicated in BTU per hour, 1 BTU/h is approximately equal to 0.293 W. So, for an air conditioner with a BTU value of 9000, the power will be 9000 * 0.293 = 2637 W (≈2.6 kW). Using the BTU indicator, you can easily determine the recommended size of a standard room in square meters: just multiply the figure indicated in the specifications without zeros by 3. For the example under consideration, the area will be 9 * 3 = 27 m².

Three zeros after indicating the BTU value are usually neglected, which is why the names of the air conditioners are "seven" (7000 BTU), "nine" (9000 BTU), etc. For greater clarity, when choosing household air conditioning equipment by BTU, you should focus on this list:

Inverter drive and noise level

The family of air conditioners can be divided into two broad categories according to the type of compressor. The first is traditional "ON/OFF" class models. Their drive works at full power until the temperature in the room reaches the desired temperature. When the set bar is reached, the compressor turns off until the temperature again exceeds the set one. Then the drive is turned on and the cooling cycle is repeated in a circle.

Traditional "ON/OFF" air conditioners have several disadvantages. Firstly, these are deviations from the set temperature up to several degrees, and secondly, increased energy consumption, due to the need to constantly turn the compressor on and off to its fullest. Now it doesn’t make much sense to buy an air conditioner with a non-inverter drive – they are obsolete, and the cost of models with an inverter is becoming more affordable (especially in the low-cost segment of air conditioning equipment).

Air conditioners with inverter are completely spared from these flaws. Their principle of operation is to abandon the alternation of on and off cycles of the drive in favor of a constant adjustment of the compressor power. When the set temperature is reached, air conditioners with an inverter motor drive do not turn off, but switch to reduced power. As a result, accurate maintenance of user-set temperature values with minimal deviations is ensured.

Models with inverter maintain the temperature much finer and smoother than air conditioners with a traditional "ON/OFF" drive.

Inverter reduces wear of air conditioner components, reduces noise level and saves energy. In addition, inverter compressors have high reliability and durability, and they are also not at risk from power surges – the inverter technology is based on the principle of voltage conversion. The quietest and most energy-efficient air conditioning equipment will definitely be equipped with an inverter drive. More about this in our article "Inverter drive in household appliances: what is it, the pros and cons of inverter".

Inverter Air Conditioners

Since we have touched upon the issues of noise level and energy efficiency, it is worth considering these specifications of air conditioners in more detail.

For split systems, the noise level parameter is indicated separately for the indoor and outdoor units. Moreover, in the case of an indoor unit, the noise value is determined when operating at the lowest speed. When choosing an air conditioner for a bedroom or children's room, it is advisable to give preference to the quietest models – with a noise level of up to 20 dB, which is comparable to a barely perceptible whisper. Do not lose sight of the fact that the outdoor unit makes much more noise. So that its work does not interfere with sleep, it is important to install the outdoor unit away from the window.

Also, the night mode of the air conditioner is usually aimed at lowering the noise level. When it is turned on, the fan of the indoor unit is set to the minimum speed to reduce noise, and the temperature is adjusted as smoothly as possible.

The indoor unit of the air conditioner operates quietest in the night airflow mode.

As for energy efficiency, air conditioners have seasonal energy efficiency coefficients for cooling and heating modes. The first option is usually denoted by the index SEER (Seasonal Energy Efficiency Ratio), the second – SCOP (Seasonal Coefficient Of Performance). The coefficients are calculated according to various formulas, and their essence is: the higher the coefficient, the more effective the device is. As a result, all values are reduced to energy efficiency classes familiar from household appliances: from A (the highest) to G (the lowest).

Until 2021, the old gradation of energy labeling classes was in use, in which the most efficient models of air conditioners were designated A+, A++ and A+++. Henceforth, the European labels indicate energy efficiency classes without "plus" prefixes – separately for cooling and heating modes (taking into account different climatic zones). The label also contains information about the noise level of the indoor and outdoor units.

The European label of air conditioning equipment indicates energy efficiency classes for cooling and heating modes (taking into account climatic zones), as well as noise levels for indoor and outdoor units.

As already mentioned, inverter air conditioners provide a minimum level of noise and energy consumption.

Optimal operating modes

Of course, the main mode for any air conditioner is air cooling. Many portable models work only for cooling. Stationary solutions usually have more modes of operation.

Air conditioners with a heating function will help to warm up during the autumn and spring off-season, when the house is already quite cool, but the heating has not yet been turned on or it has already been turned off. Usually, air conditioning equipment with this option is designed to work in slight frosts (down to -7 °C or even down to -15 °C). The heating mode in such devices is designed to supplement traditional heating systems, rather than to replace them.

Air Conditioners with Heating Function

Good to know. In air conditioners with a heating mode, the emergency heating function is often found. It is aimed at maintaining a small plus temperature in an unheated room (about +8..10 °C). This is enough to avoid freezing of the walls and damage to communications.

Recently, more and more models have been produced for heating in severe winter frosts ( -21 ... -25 °C and even below -25 °C). Such air conditioners are equipped with systems for automatic heating of the compressor crankcase and defrosting of the heat exchanger for unhindered start-up of the device in cold weather. In terms of capabilities, they come close to full-fledged heat pumps and can be used in winter.

The vast majority of household split systems support heating mode.

Fresh air intake option is an attribute of advanced air conditioners . Devices with this function not only change the temperature of the air in the room, but also additionally refresh it. Fresh air intake significantly complicates the design of the air conditioner, and the price tag of such devices skyrockets. This option is found mainly in premium models.

Any air conditioner dries the air. This problem can be solved in models with humidification mode, capable of working to increase the humidity in the room. The humidification function is extremely rare – it is typical for flagship air conditioners. This is due to the fact that in everyday life it is easier and cheaper to get a separate humidifier.

Air conditioners with a built-in ionizer saturate the air in the room with air ions that are beneficial for health and improve well-being.

In air conditioners of the middle and top level, the ionization mode is often provided – air saturation with negatively charged air ions. Under natural conditions, air with such particles is present near waterfalls, on mountain slopes, and off the coast of natural reservoirs. It is claimed that air ions provide a surge of strength, strengthen the immune system and generally improve well-being.

Air purification

Almost all modern air conditioners have at least coarse filters to trap large dust particles floating in the air. But for air purification, other filters can be used, supplied both as standard set and purchased separately. The most common types of filters used in air conditioning systems are:

  • plasma (electrostatic) – works on the principle of saturating the air with negatively charged particles (like the ionizers mentioned above); plasma filters effectively destroy bacteria and viruses, trap particles of dust, smoke and soot;
  • antibacterial – used to neutralize harmful microorganisms: viruses, bacteria and fungi;
  • catechin – a kind of antibacterial filters with catechin as an active disinfectant;
  • catalytic – such filters work due to a special substance (photocatalyst) and UV radiation; the catalyst under the influence of UV rays decomposes organic matter into simpler substances – usually water and carbon dioxide; the technology allows to remove harmful impurities from the air at the level of individual molecules, provides a good bactericidal and antiviral effect;
  • deodorizing (charcoal) – filters to combat unpleasant odors such as cigarette smoke; The classic type of deodorizing filters are elements based on activated carbon.
Air Conditioners with Antibacterial Filter

Less often, air conditioners use anti-allergic and anti-fungal filters, HEPA filters, formaldehyde filters and other highly specialized elements. Also, models with a UV lamp have a good bactericidal effect on the air.

Useful features

In the list of the most important features,I Feel is in the first place. This name is usually given to the temperature sensor in the remote control. Relying on the readings of the temperature sensor in the remote control, the air conditioner more accurately regulates the microclimate in the immediate vicinity of the user. Models without this function are guided by the location of the indoor unit in which the temperature sensor is installed, and at the user's location, the microclimate parameters may differ from the set parameters.

To keep the inner surfaces of the indoor unit in good shape, the self-cleaning function will be useful. It is carried out by pumping air, which dries out the "insides" of the air conditioner, thereby preventing the growth of bacteria and fungi.

To prevent jets of cold air from getting directly on people, some air conditioners have a drive not only for horizontal, but also for vertical blinds. It allows to rotate the duct flaps from side to side, changing the direction of the air flow horizontally.

The temperature sensor in the remote control allows to more accurately control the microclimate parameters near the user.

Air conditioners with a motion sensor scan the room for people presence. If there is someone in the room, the air conditioner can change the direction of the airflow away from people to avoid drafts. In the absence of anyone in the room, the air conditioning equipment switches to an saving mode of maintaining a comfortable temperature or turns off completely if there is no activity in the room for a long time. Of the other sensors in advanced air conditioners, there is an air pollution sensor, which monitors the quality of the air masses in the room.

Air Conditioners with Motion Sensor

In the current era of modern technology, many air conditioners belong to the smart technology class. It is possible to manage their work remotely from a smartphone. Connection with mobile gadgets can be carried out via Bluetooth or Wi-Fi, depending on the model. In some devices, to unlock the smart potential, you may need to use an external Wi-Fi module.

You can remotely control the operation of many air conditioners from your smartphone.

Smartphone control will come in handy to turn the air conditioner on or off remotely, to schedule its operation, track energy consumption statistics, etc. It is much more pleasant to return home in the scorching summer heat turning on the air conditioner for cooling in advance. A number of advanced models of air conditioning equipment have gone even further – some instances of air conditioners have acquired support for voice control through virtual assistants in the manner of Google Assistant or Amazon Alexa.

Popular brands

The segment of air conditioning equipment is very large and diverse. We have already talked about the gradation of brands of air conditioners in detail in the article “Choosing a home split system”. Here are the main excerpts from the article for understanding the essence:

1. Elite division. This category includes products of reputable brands Daikin, Mitsubishi Heavy, Mitsubishi Electric, Fujitsu. The service life of air conditioners of these brands often exceeds 10 years, and the percentage of low-quality goods is so negligible that the chances of buying them are practically reduced to zero.
2. Reliable and affordable Japanese brands. This group includes the second tier of manufacturers of household air conditioners, which have excellent consumer properties and are distinguished by a more affordable pricing policy. This includes the Hitachi, Panasonic, Sharp brands.
3. Solid mid-range. Most models from this category support inverter, and besides, they are affordable for any buyer. These are the products of Cooper & Hunter, Toshiba, Carrier, Sanyo, Gree, Midea.
4. Economy class. The largest group of air conditioner manufacturers, which are united by a focus on a target audience with a relatively low income. This impromptu list includes just inexpensive brands, among which there are quite good models, as well as outsider brands with a characteristic squeaky and yellowing plastic of the indoor unit. The economy league of air conditioners is represented by LG and Samsung brands (with some exceptions), TOSOT, Hisense, Haier, Ballu, TCL, etc.

Other things being equal, it is desirable to give preference to the air conditioning equipment of a higher rank. More details about “What is the difference between a cheap air conditioner and an expensive one?” in this article.


Have a comfortable coolness in summer, pleasant warmth in winter and in the off-season!