Air conditioners designed to create comfortable conditions for human life and work by providing the room with an optimal temperature regime, ideal humidity, and a constant supply of fresh air are increasingly used in our daily life. Whether the technique will cope with its functions depends on the intelligent choice of its type and type.

The topic of our today’s conversation will be not only household but also industrial air conditioners, their types, types, and devices. This will advise you not to “get lost” in the highly diverse market of modern climatic technology and choose an air conditioner according to your tasks and needs.

Household air conditioners

The power of household air conditioners can vary depending on the model, from 1 to 10 kW. This is sufficient for air conditioning in rooms ranging from 10-20 to 80-100 m². Such air conditioners are intended primarily for private houses and apartments but can also be found in a small area’s office or retail premises.

Considering the purpose of domestic air conditioners, their manufacturers focus on increasing the comfort of use by reducing noise levels, adding new functions, and improving the indoor unit’s design.

Most household air conditioners are designed to last 8-10 years. However, many consumers, succumbing to modern trends, replace them earlier since new models with more interesting additional functions constantly appear on the market.

Monoblock air conditioners

All elements of a monoblock air conditioner, as its name suggests, are housed in one housing. A consequence of the simplicity of the design is the relatively low cost of equipment, which is the main advantage of monoblock systems.

There are two types of air conditioners for an apartment without an outdoor unit:

  • stationary (window);
  • mobile.

1. Mobile air conditioners

A mobile air conditioner is the only air conditioning equipment that the user can install without a specialist. This task is the most simple one: it is enough to bring out a flexible duct hose designed to remove heated air through an open window or window, and the air conditioner is ready for operation.

Another undoubted advantage of mobile air conditioners is the ability to move them: if necessary, the equipment can be easily moved to another room, transported to a newly rented apartment, or even taken with you when going to the dacha.

On this, alas, the advantages of mobile air conditioners end, only disadvantages follow.

  • Firstly, the air conditioner is not very mobile within the room: it should be located near the window, since the length of the air duct hose is small, and it is not recommended to lengthen it.
  • Secondly, the air conditioner’s compressor produces a rather loud noise, which blocks even the sounds coming from the forcedly open window.
  • Thirdly, the owners of such systems will have to remove the accumulating condensate regularly manually.

2. Window air conditioners

Window air conditioners, the back of the case of which is exposed to the street through a hole in the glass, were once very popular, but today the demand for them has fallen sharply, and therefore they have become much less produced. The fall for such models was a consequence of the appearance of split systems, with which the “windows” could not stand the competition.

Indeed, window monoblocks have many disadvantages. They have low power, but they make a lot of noise. Only a few know how to heat the air, while most have only a cooling mode. In addition, installing a window air conditioner is an inevitable violation of the thermal insulation of the room, which is critical for residents of many regions of our country.

The low cost and ease of installation are the only advantages of window air conditioners, which practically do not compensate for the disadvantages listed above.

Split systems

The split system is a two-unit air conditioner, more popular today than monoblocks. Its structural elements are divided into two blocks – indoor (indoor) and outdoor (street). These blocks are located at different points in space but are interconnected by pipes through which the refrigerant circulates.

Thanks to this design solution, the noisiest unit of the air conditioner – the compressor – is taken out of the room. The quiet and compact indoor unit can be placed almost anywhere in the room – where it is most convenient for you.

1. Wall split systems

Wall split methods are the most popular and, therefore, the most common type of air conditioner today. They are often called room or home air conditioners since they are usually installed in private houses and apartments. The power of household wall-mounted split systems can vary from 2 to 10 kW, depending on the selected model.

2. Fixed multi-split systems of wall type

Two or even three indoor units can be connected to one external unit of such an air conditioner. In this case, each will be configured individually from its control panel. Such “constructors” are called multi-split systems. Multi-systems for domestic use are sold as ready-made kits, which do not leave the user room for maneuvers: it is impossible to change the number of connected indoor units and their total capacity.

For all their apparent attractiveness, the use of multi-split systems is rarely used. As a rule, they are chosen only when there is a reluctance (or impossibility) to place several external blocks on the house’s outer wall (you must admit that the latter do not decorate the facade of the building). The fact is that, contrary to popular belief, you will not be able to save money by replacing several split systems with one multi-split.

The total cost of equipment in both cases will be approximately the same, but the cost of installing a multi-split system will be 1.5-2 times higher since the length of communications will increase.

Commercial air conditioners

Commercial air conditioners, ranging from 10 to 30 kW, occupy an intermediate position between household units and industrial systems. They can be used both in private houses and in offices, shops, catering establishments, and other premises with an area of ​​up to 300 m².

Cassette air conditioners

Cassette-type air conditioners are designed for installation behind a false ceiling that completely hides the indoor unit of the device. The bottom panel of the team, through which cooled air is discharged, has the size of a standard ceiling tile (600 × 600 mm) and is covered with a decorative grill. As a result, the cassette air conditioner is practically invisible, one of its main advantages.

Duct air conditioners

The indoor unit of the duct-type air conditioner is also hidden from view behind the suspended ceiling. However, in this case, the distribution of cooled air is carried out employing a system of air ducts, which are also located in the space between the floor slabs and the false ceiling. Thanks to the branched air duct system, such a device can be used for air conditioning in several adjacent rooms at once.

The disadvantages of such air conditioners include the complexity of independent regulation of the air temperature in different air-conditioned rooms. To solve this problem, it is required to install valves with electric drives in the air ducts and install thermostats in all rooms.

However, if you do not differentiate between residents of different rooms and maintain the same temperature everywhere, you will not have to take additional actions.

Ceiling air conditioners

Not every room has a suspended ceiling, and walls (for example, made of glass) sometimes do not allow a conventional wall split system installation. A floor-ceiling air conditioner will come to the rescue in this seemingly hopeless situation. Its distinctive feature is the small thickness of the indoor unit (usually 20-25 cm). Install such an air conditioner near the wall: either horizontally, on the ceiling, or vertically, on the floor.

In the first case, the airflow is directed along the ceiling, in the second – up, along the wall. And in fact, and another point, situations are practically excluded in which a direct flow of cold air hits the people in the room, which many who have dealt with air conditioners will consider a huge plus.

Column conditioners

The column air conditioner is heavy and therefore is not suspended but installed directly on the floor. In terms of its dimensions and features, it resembles a large household refrigerator. Still, in reality, it takes up much more space than the latter since the vital flow of cold air created does not allow being near the installation for a long time.

Column air conditioners are used in conference rooms, hotel lobbies, offices, shops, warehouses, and other premises where, on the one hand, high refrigeration capacity is required, and on the other hand, there is no possibility to use walls and ceilings for the installation of more conventional split systems.

“Type-setting” multi-split systems

As in the case of household split systems, the commercial and semi-industrial HVAC equipment can be produced in the form of multi-split systems. In this case, one outdoor unit can serve up to five indoor units. Multi-split systems for semi-industrial purposes, in contrast to household ones, are supplied not in fixed sets but type-setting. This means that the buyer has the right to choose the type and capacity of the indoor units himself. There are only restrictions on their maximum number and total power.

Industrial air conditioners

Traditional split and multi-split systems are powerless for all their advantages when air conditioning is not in a private house or a small cafe but at some large facility. You can, of course, hang the walls of a shopping center with hundreds of external blocks, but this is, firstly, unaesthetic, and secondly, economically unprofitable.

There is a way out – an industrial air conditioner, the power of which can reach 200–10000 kW. Such installations can provide comfortable conditions for people to stay in buildings of any size and number of stories all year round. They, therefore, are successfully used at a wide variety of facilities:

  • large office centers and government agencies,
  • shopping and exhibition centers,
  • hotels,
  • medical institutions,
  • catering establishments,
  • theaters and concert halls,
  • museums and libraries,
  • indoor stadiums, swimming pools, and sports complexes,
  • pharmaceutical and other industrial enterprises, etc.

One centralized installation serving the entire building is ultimately cheaper than split systems in each room: the increased initial costs are offset over time by reduced energy consumption and savings in maintenance and repairs. In addition, industrial air conditioners are installed in technical rooms or on the roof, which means they do not spoil the facade of the building and do not interfere with their noise for workers and visitors.

The resource of industrial systems designed to control and maintain an optimal microclimate at extensive industrial and semi-industrial facilities is at least 20-30 years. The choice of the type and characteristics of the air conditioner is carried out, taking into account the area of ​​the building, its purpose, and the intensity of the equipment operation.

Multizone VRV and VRF systems

The multi-zone VRV system is essentially an improved version of the conventional multi-split system. But unlike the latter, VRV allows connecting not several pieces to one external unit but several dozen internal ones. In addition, the maximum allowable distance between the indoor and outdoor units has been increased: now it can no longer be 10-25, but 100 meters.

How did you manage to achieve such a dramatic change? Whereas in conventional multi-split systems, each indoor unit is connected to an external separate freon line, in VRV systems, all units are connected to a single pipeline consisting of two or three pipes. The amount of refrigerant supplied from a standard route to a particular indoor unit depends on the heat load on this unit and is regulated by an individual thermostatic valve.

This technical solution allows you to significantly reduce the power loss of the air conditioner when hanging another indoor unit or increasing the distance to it. In addition, installation work is accelerated and cheaper, and, more importantly, it becomes possible, if necessary, to quickly modernize the system, including expanding it.

As in conventional multi-systems, indoor units can be of different types and capacities (usually from 2 to 25 kW). In this case, each block can be assigned its mode, and it can be controlled both with the help of individual remote controls and a centralized remote control or a personal computer.

In addition to VRV (Variable Refrigerant Volume), there are VRF (Variable Refrigerant Flow) systems. In principle, they do not differ; different designations are sole because VRV is a registered trademark of Daikin, which means that other manufacturers cannot use this abbreviation.

Chiller – fan coil systems

The fundamental difference of the chiller-fan coil system from all other air conditioning systems is that the role of the coolant is played not by the gas refrigerant but by water (in regions with cold climates, it is replaced by a liquid that does not freeze in moderate frosts, most often an aqueous solution of ethylene glycol).

Chiller cools water – a device designed specifically for cooling liquids. Chilled water is pumped through pipelines to the fan coil units. The latter plays the same role as the internal blocks of conventional multi-split systems, i.e., condition the air in the premises.

Comparison of the chiller-fan coil system with a traditional multi-split system that uses freon or other gas refrigerants in its operation reveals several advantages of the first:

  • The number of fan coil units in the system is limited only by the chiller capacity.
  • Due to the high heat capacity of the water, the losses of the transferred cold for each running meter of the track are insignificant. The maximum permissible distance between the chiller and the fan coil unit depends solely on the power of the pumps driving the coolant through the pipes and can reach hundreds of meters.
  • Instead of expensive copper communications, the most common water pipes connect the chiller to fan coil units. Thanks to this, the installation and maintenance of the pipeline are significantly cheaper and more accessible than in the case of gas-filled systems.
  • The facade of the building is not “decorated” with a garland of external air conditioning units. The chiller can be installed in any convenient place, for example, in the basement, in the attic, or entirely outside the building.

Central air conditioners

In principle, the term “central air conditioner” can be applied to any industrial system. However, it is also used for a particular type of air conditioner – modular. Such air conditioners are designed to solve various tasks – cooling or heating, humidification or dehumidification, ventilation, and air purification.

Central air conditioners are produced as a set of standard modules, each of which is designed to perform a specific function:

  • The cooling module is an external condensing unit operating on freon or a chiller that cools water.
  • The heating module can be made in one of two versions. It can be either a water heater (a heat exchanger connected to a central or autonomous heating system) or an electric one (a system of conventional heating elements).
  • The ventilation module is designed to draw in fresh air from the outside and supply it to conditioned rooms. A noise suppression system is often additionally used to reduce the noise generated by the fan module – a set of sound-absorbing plates made of fiberglass or mineral wool.
  • The humidification module includes a spray chamber or steam humidifier. If air humidification takes place in the nozzle chamber, a prerequisite is the installation of a droplet separator, which prevents unsprayed water droplets from entering other modules of the system.
  • The filtration module is designed to remove dust from the air supplied to the air-conditioned rooms. For increased air quality requirements, two filtration modules are installed. In the first, coarse filters are placed (retain up to 60% of dust); in the second – fine filters (keep up to 90% of dust).

The dimensions of each section are unified and usually range from 0.5×0.5 to 2.5×2.5 meters. The layout of the air conditioner depends primarily on the purpose of the premises and its area and is made individually for each facility.

Rooftop air conditioners

A rooftop air conditioner is a monoblock unit installed on the roof of the building. In its structure, it resembles a considerable window air conditioner. Still, in addition to standard units, its design often has a special chamber designed to mix the air taken from the room and outside and a heating element for heating the air in the cold season.

The power of rooftop air conditioners can vary, depending on the model, from 8 to 140 kW, while they drive from 1,500 to 25,000 cubic meters of air per hour. Typically, such systems are used for air conditioning in large one-story rooms with a standard roof – trade, exhibition and conference rooms, indoor stadiums, etc.

Cabinet air conditioners

The cabinet air conditioner is a monoblock installed indoors (systems with a remote condenser are less common). The cooled air is supplied through the top panel directly into the room or the duct system. Since all structural elements of the cabinet air conditioner are in an easily accessible place, it is pretty simple to install and maintain it.

In addition, placing the air conditioner compressor indoors ensures that the unit will function properly regardless of the outside temperature.

Cabinet air conditioners are usually used in industrial premises where constant maintenance of the set temperature is required. The cooling capacity of such air conditioners is from 10 to 80 kW.

Precision air conditioners

Precision air conditioners are one of the types of cabinet air conditioners. Unlike their usual counterparts, deprived of special status, they can maintain a given temperature with high accuracy (deviations in one direction or another do not exceed 1 ° C). This, however, is not their only benefit: they control and maintain air humidity with equal accuracy. The latter is achieved by adding additional units to the unit design – a hygrostat and a humidifier.

As a rule, a precision air conditioner is a two-unit system, but, despite this, it does an excellent job of its work even in the cold season (down to -35 ° C). Air distribution can be carried out both through the upper panel and the lower (raised floor).

The primary purpose of precision air conditioners is to maintain a suitable microclimate in the premises of libraries and book depositories, museums, pharmaceutical laboratories, some industrial premises, computer rooms, etc. Often they are included in the general automated system for monitoring and controlling the building microclimate.

Inverter and linear air conditioners

All air conditioners, regardless of power, size or purpose, are divided into linear and inverter. The fundamental variation between these two types is the presence or absence of an inverter that allows you to change the compressor motor speed smoothly and, as a result, the power of the air conditioner itself. Let’s figure out what this means from a practical point of view.

Linear air conditioner

The linear air conditioner has a fixed power. If it is not too hot outside, only slightly cooling the air in the room is needed to achieve a feeling of comfort, this power may be excessive, but it cannot be changed. That is why linear air conditioners operate in the mode of constant stops and starts of the compressor engine (often, such air conditioners are even called start-stop).

The compressor will turn off when the temperature sensor notifies the system that the room temperature has dropped by 1-2 ° C below the set value. When the temperature rises again, the compressor will start operating at total capacity again.

A predictable disadvantage of this technical solution is the strong fluctuations in the air temperature inside the conditioned room. Alas, it is practically impossible to avoid these fluctuations: more accurate maintenance of the set temperature parameters can be achieved only by turning the compressor on / off too often, but this is fraught with the rapid deterioration of the latter.

Another significant disadvantage of linear models is the flow of icy air emanating from the indoor unit. Since the air conditioner operates at total capacity, the air passing through the evaporator is cooled by ~ 15 ° С, regardless of the value set by the user on the control panel. Being under such a cold stream is very uncomfortable and unsafe for health.

Inverter air conditioner

The inverter air conditioner has variable cooling capacity. (The documentation for such models usually indicates not one power value but the range it can change.) This is achieved because, in the inverter, the alternating current is converted into direct current and then back, but with a different frequency. This makes it possible to change the speed of the compressor engine smoothly, and therefore smoothly adjust the power of the air conditioner.

What does this mean in practice? If the room temperature is very different from the comfort temperature for the user, the compressor will run at total capacity, and the air will cool down quickly enough. When the temperature reaches the set value (or instead, it has not yet arrived but is already as close as possible), the compressor will not turn off, as it happens in linear air conditioners but will reduce the speed. As a result, inverter models more accurately than linear ones maintain the set temperature, creating more comfortable conditions in the room, making less noise, and significantly saving energy.

Perhaps the only drawback of inverter air conditioners is their high cost. Otherwise, they would have long ago ousted linear models from the market.

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