The principle of operation of the air conditioner: device and diagram

Author: Site editors

Publication date: 30.04.2019

Issues discussed in the material:

General principle of operation of the air conditioner
Operating principle of a duct air conditioner
Operating principle of an inverter air conditioner
Operating principle of precision air conditioners
How a window air conditioner works
Operating principle of a mobile air conditioner without duct

Air conditioning, as equipment for ensuring a comfortable temperature in rooms, is distinguished by a complex electronic device. Normal operation of such devices without expensive repairs is possible only with professional installation and qualified maintenance. To avoid complications and unexpected breakdowns during the operation of climate control equipment, it will be useful to know the operating principle of the air conditioner. In this article we will look at the technological features of different types of air conditioners and the possibilities of their use.

How does an air conditioner work?

The system operates on a closed cycle principle. The air in the room is cooled by passing through the heat exchanger of the indoor unit, in which the refrigerant evaporates. Let's look at the operation of the device step by step.

The compressor installed in the outdoor unit compresses the refrigerant and pumps it into the condenser in a gaseous state from the evaporator of the indoor unit.
In the condenser, the freon is cooled due to heat exchange with the outside air and condenses. All this happens in the heat exchanger of the external unit.
Next, the refrigerant passes through a throttling device, where a sharp decrease in freon pressure and temperature occurs. In this case, part of the liquid refrigerant inevitably turns into a gaseous state.
Cold freon enters the heat exchanger of the indoor unit (evaporator), where, due to heat exchange with the air from the room, it boils and passes from a liquid to a gaseous state. The air, in turn, is cooled and enters the room.

Due to the way the air conditioner operates, drops of water—condensation—form on the evaporator. Typically, when installing a system, a separate pipe is installed to drain condensate. It goes outside or into the sewer so that there is no excess moisture in the room.

The direction of the exhaust air from the indoor unit is adjusted using a special curtain and blinds horizontally and vertically.

Indoor unit

An indoor air conditioner is necessary to provide cool air in the room. The design of this unit allows you to take in air from the street and distribute it evenly in the room. In this regard, the main elements of the internal structure are:

Radiator (evaporator). It received this name because during the cooling stage freon evaporates in the tubes, and the principle of operation of the circuit is based on this phenomenon. The power of the unit largely depends on the size of this device: the larger the air conditioner, the larger the evaporator should be.

It is an interlacing of tubes with plates that increase the plane of heat transfer. The refrigerant moves through the capillary vessels at a certain speed and temperature.

Fan (impeller, shaft). To quickly cool the room, it is necessary to force the air flow through a cooled radiator. This is where this impeller helps.

For many models, the evaporator outlines the fan configuration, thereby making the installation of the internal module compact. This creates effective circulation of air masses.

Fan motor . It is attached with a special bracket to the module box and serves to rotate the impeller.

Drainage bath . During operation of the air conditioner, condensation forms on the radiator. And this tray exists to collect it. In addition to moisture, it collects dust, dirt and other foreign particles. Therefore, for better care, this device is removable.

Vertical and horizontal blinds. These elements move from small motors and are attached under the drainage tray. At the same time, horizontal curtains regulate the air flow up and down, and vertical ones - left and right.

Command block . This microcircuit is a board to which all significant starting elements of motors and sensors are connected through wires.

Coarse filter . It looks like a plastic mesh to which small particles of dust, dirt, and wool stick. This filter needs to be cleaned once every two weeks to avoid overloading the engine.

How does an inverter air conditioner work?

The peculiarity of this device is that the compressor turns on once during the entire operation of the air conditioner and remains in this state constantly, changing the speed depending on the load on the air conditioner. In turn, a conventional air conditioner (on/off) periodically turns on and off without changing the speed. The inverter saves energy and extends the life of the compressor, since it works without turning on/off, but smoothly changing the number of revolutions.

An inverter model will be more economical than any other air conditioner if it runs for at least several hours without turning off.

The inverter model, like a conventional air conditioner, has two units - external and internal. The external one contains a compressor, copper freon pipelines, a fan and a condenser. The indoor unit consists of an evaporator, a fan, blinds, a filter and a special tray for the condensate formed.

External part of the air conditioner

The external unit of the device is installed outside the room and includes the following components:

Fan. Its task is to cool the condenser;
Capacitor. In other words, this is a radiator that is necessary for cooling and condensing the freon liquid. The air flow, assimilated near the condenser, is heated and then released outside;
Compressor. It is necessary for compressing the refrigerant, and it also supports its passage through the refrigeration duct;
Modern inverter air conditioners have a control board. In addition to it, this type of equipment contains many other electronic elements;
Some equipment models that have a heating function have a built-in four-way valve. When the equipment is operating in heating mode, the valve is able to change the direction of movement of the working fluid (freon). At this very moment, the internal and external parts of the equipment seem to change places with each other and do not do their job;
Union connections. They are designed for connecting copper tubes that connect the internal and external parts of the equipment;
The filter located at the compressor outlet is necessary to protect freon and the compressor from dust and dirt particles that may settle in the system during installation work;
A protective base (or cover), which is designed to protect fitting connections. In addition, they cover the electrical connectors of the device.

Design and principle of operation of a split system

The usual classic split system consists of two modules (blocks) - external and internal. The design of the external unit of an on/off type split system is almost always the same.

External unit

The external unit includes a compressor, a condenser, a four-way valve, and also has a capillary tube.
All units contain a filter drier that cleans and dries the refrigerant from possible moisture entering the system and various types of contaminants. In inverter-type split systems, the external unit also contains a control board, which is also found in multi-split systems. Due to the fact that the compressor is located in the outdoor unit, the noise level from a working air conditioner in the apartment is much lower than from the street. The dimensions of the external unit may vary depending on the performance of the model, as well as the brand.

The indoor unit is connected to the external unit using freon pipelines. There is also a drainage line and an electrical cable to power the indoor and outdoor units.

The external unit of the air conditioner should always be located on the street side. It is attached to the outside of the wall. If the air conditioner needs to be installed at a sufficient height from the ground and it is not possible to mount the outdoor unit in the usual way, then climber installers with special gear and equipment are invited. Without such devices it is impossible to install the external unit high. Also, the outdoor unit can be installed on the roof of buildings, on unglazed balconies and loggias, open common balconies or flights of stairs with open access to the street. Often external blocks are supplied in a vandal-proof casing; if this is not provided by the manufacturer, then a block installed at the level of the first floors can additionally be placed in a special protective box made of metal rods. To prevent the accumulation of snow or rainwater, as well as debris, a special sloping canopy is sometimes installed over the external units.

Indoor unit

The internal units of a split system differ significantly from each other. Firstly, it depends on the manufacturer, i.e. all internal units differ in design, and secondly, the units differ in the type of installation, and, accordingly, have a significant difference not only in the design of the front panel, but also the housing as a whole. Also, indoor units, depending on the manufacturer, power and model, may differ in components, functionality, and overall dimensions.

Split system indoor units can be of the following types:

wall-mounted – they are designed for installation on a wall;
cassette - placed in the area of the ceiling space;
duct - installed in the area of the ceiling space with an air duct system;
floor-subceiling – can be installed both on the floor and in the area under the ceiling;
columned - installed on the floor, they are large in size compared to other types of indoor units of classic split systems.

The operation of the indoor unit is regulated thanks to an electronic board. The indoor unit contains filters for air purification, automation, an evaporator and a fan for blowing the evaporator heat exchanger. The main functions of modern split systems are ventilation, dehumidification, cooling, heating and maintaining a given room temperature. Control using remote control. Almost all modern models of split systems are equipped with a remote control. With its help, you not only turn the device on and off, but also control all functions - setting the temperature mode, turning on the timer, programming tasks, turning on all modes provided for a specific air conditioner model. If the model has the “I feel” function, then thanks to the temperature sensor in the remote control, the air conditioner monitors the ambient air temperature in the room, and when the temperature set by the user is reached, the equipment maintains it. On the indoor unit, the direction of the air flow is adjusted by changing the angle of the blinds. The operation of the compressor of the external unit is regulated by constant monitoring of all systems.

Features of the functioning of floor air conditioners

These models are rarely used if a standard split cannot be installed. Floor-standing air conditioners are also only stationary. Stationary models have a similar operating principle as a conventional air conditioner, with the exception of the installation of an indoor unit. It is not located under the ceiling, but at a height of half a meter from the floor. The external unit is located on the street. Such split systems belong to the semi-industrial series. As a rule, they are more productive than household models.

Features of mobile models

The mobile model has only one unit and is located indoors. It contains a compressor, evaporator and condenser. The functioning mechanism is based on the processing of indoor air.

Usually it is not recommended to choose a mobile model, since the noisiest part will be installed not outside the window, but indoors. When the air conditioner is on, you will feel uncomfortable in the room. In addition, they are characterized by low power.

Types, types, additional functions

Modern household air conditioners can serve up to 90 square meters. m. But if we are talking about a large cottage or office, it makes sense to think about installing more productive devices. The problem of air conditioning such facilities is solved using multi-split systems or semi-industrial models.

The diagram clearly demonstrates the operating features of a split system: the refrigerant inside the room is heated, moved to the outdoor unit and cooled, then returned to the room again

A multi-split system makes it possible to install several indoor units, which are connected to one common outdoor unit. Economically, such a solution may turn out to be more profitable than using several conventional split systems; the appearance of the facade definitely benefits.

An alternative to solving the problem of air conditioning a large building can be a chiller-fan coil system. If the area of the office or cottage approaches 500 sq. m or slightly exceeds it, it makes sense to think about using a semi-industrial split system.

The duct version of such a device allows you to mount the device and the duct leading to it under a suspended ceiling without damaging the appearance of the room. These devices are capable of not only purifying and cooling the air available in the room, but also taking in fresh air from outside, which significantly improves the microclimate.

Cassette air conditioners are installed so that the grille through which air is supplied becomes part of the suspended ceiling. Cold air spreads throughout the room quickly and evenly. Read more about the operating principles of cassette splits below.

In rooms with complex shapes or where there is no suspended ceiling for some reason, floor-ceiling systems are installed.

What is the difference between an air conditioner and a split system

An air conditioner is complex technical equipment designed to create and maintain a comfortable temperature in a room for any purpose.
An air conditioner can not only cool the air, but also heat it, if provided by the manufacturer. Air conditioning is a general concept of climate refrigeration technology. There are many types of air conditioners available today. An air conditioner can be called both a household appliance for cooling air, for example, a window air conditioner or a mobile air conditioner, and a chiller - high-power industrial climate control equipment. For a more precise definition, there are names of air conditioners, for example, split system. A split system is an air conditioner consisting of two units - external and internal. The indoor unit includes a control system - automation, filters for air purification, a fan for blowing the evaporator heat exchanger and the evaporator itself. The external unit includes a compressor, a condenser, a four-way valve, a capillary tube and an automation system.

A household split system is most often installed in relatively small rooms; for example, a household wall-mounted split system is designed to create an optimal microclimate in rooms from 10 to 70 m2, depending on the power of the equipment. Therefore, such split systems are most often installed in apartments or small office spaces.

One indoor unit is capable of maintaining the temperature in one room; if you need to maintain the temperature in several rooms at once, then there are multi-split systems for this. This system involves connecting several indoor units to one outdoor unit at once.

There are also other types of split systems that are more suitable for large spacious premises - shopping centers, restaurants, business centers, etc. All of these split systems also have one internal and one external unit; they differ only in the internal units and performance. Indoor units are divided by type of installation - cassette, duct, column, floor-ceiling, column.

Split systems may differ in options and functions, depending on the model and manufacturer. For example, split systems may have different numbers of cleaning air filters. The number of modes may also differ - some air conditioners have the following popular modes - “I feel”, night mode, self-cleaning, auto-restart, auto-shutdown, self-diagnosis, turbo mode, intelligent defrost, etc.

Related to heat pumps

The design of the inverter split system and the air heat pump (HP) is identical. Both units use the principle of a refrigeration machine, taking heat from outside air and heating the inside. Differences in design - in order to increase efficiency, the area of the external heat exchanger-evaporator HP is significantly increased, so the unit is often placed on the ground, as shown in the photo below.

Geothermal pumps that extract heat from the ground are also structurally close to split systems. The difference is in the method of selecting and transferring heat to an external evaporator - here, instead of street air, a non-freezing coolant is used, flowing through the loops of underground circuits. The main operating cycle is identical - brine or antifreeze evaporates freon in the heat exchanger, releasing heat to the air or water heating system.

How to choose a split system for your home

When choosing an air conditioner for home use, consider the size of the room. For a small room (up to 15-20 meters), a 7000 BTU system is suitable. For a room up to 25 square meters, it is better to choose a more powerful model - 9000 BTU.

Think about electricity costs and choose energy-saving A++ models, consumption of about 700-800 watts. If your budget allows, you can buy an A+++ air conditioner with a consumption of 500-600 watts.

Assess the noise level. If possible, listen to how the system works, because you will have to be in the room while the air conditioner is running. The permissible noise value for the indoor unit is 19-32 dB.

The basis of the operating principles of different climate systems

Split systems and mobile, as well as window air conditioners, have different operating principles, but are based on the property of any liquid to absorb heat during evaporation and release it during condensation. In these cooling devices, the working fluid is gas - freon. It circulates in a closed circuit for two-component blocks and monoblocks.

The phase transition temperature, when the gas becomes liquid and then returns to its normal state, depends on the operating pressure - the higher it is, the higher the phase transition temperature.

In order for liquid freon to boil and take heat from the air, the compressor creates pressure in the evaporator, at which the phase transition temperature is lower than the ambient temperature. When the compressor creates a pressure at which the phase transition temperature is higher than the air, freon again takes on a gaseous state and transfers the collected heat outside, that is, to the street, through the external unit.

If we consider the principle of operation of a floor-standing air conditioner without an air duct, then the same property of the liquid is used here, but the working substance is water, not freon. There is no closed circuit inside the device. The liquid is pumped upward by a drainage pump and evaporates under the influence of warm air, releasing coolness to the outside. In fact, it is more of an evaporator than an air conditioner, since it humidifies the air well, but cools it mediocre.

Advantages and disadvantages of air conditioners

If you are looking to buy an air conditioner or split system, you will want to know the pros and cons.

Advantages

Ensuring a comfortable temperature in the room. Regardless of the weather outside, the split system will create a favorable atmosphere in the room. In the summer, the air conditioner will cool the air, and in the fall or spring it will heat it up. In any case, it will be comfortable to be in the room.
Clean indoor air. This is especially true for residents of large cities living in industrial areas. Using an air conditioner will allow you to get cool, clean air without opening the windows.
Maintaining optimal air humidity. Some models have a dehumidification function, creating an optimal level of humidity in the room.

Flaws

Please note that the air conditioner can cause harm to humans only if used incorrectly. If you do not clean the unit regularly, harmful bacteria and viruses can begin to multiply in it.

Due to the way the air conditioner operates, the air in the room becomes drier, so we recommend using separate devices that increase the humidity level in the room.

Compressors make a little noise during operation. Usually the compressor is located in the outdoor unit, and you can’t hear it working indoors.

Design

The device can be in the form of a monoblock or have a two-module design. The device is a closed system through which a refrigerant moves - most often freon R-22, R-410.

What does the air conditioner consist of?:

Compressor - designed to compress freon and ensure its movement to the heat exchanger;
Condenser - located in a remote unit, falling on the cooled surface of the heat exchanger, the refrigerant turns into a liquid state;
Evaporator - located in the inner casing, absorbs heat, allowing cold air to enter the room, converts the refrigerant into gas;
The pressure regulator (capillary tube, throttle) performs the functions of sharply reducing freon p and t;
Fan - generates an air stream directed at the heat exchangers.

Attention! Basic design elements are present in any air conditioner model.

The classic diagram of an air conditioner and its operation is shown in the figure.

The diagram of an air conditioner in cooling mode clearly shows how the refrigerant absorbs during evaporation and releases heat during condensation. The operating principle of an air conditioner is that it takes in thermal energy on one heat exchanger and releases it on another, called the vapor-compression refrigeration cycle.

How does air conditioning work?

Freon enters the compressor in the form of gas at a low p of 3-5 atm and t +10-20˚С. In the unit, the gaseous substance reaches a pressure of 15-25 atm with a simultaneous increase in temperature to +70-90˚С.

The refrigerant moves under pressure to the condenser, where it is blown by the fan and cools and turns into liquid, releasing thermal energy. The air leaving the condenser is heated. The coolant leaves the heat exchanger at a temperature 10-20˚ higher than the surrounding air.

In the choke, which is a thin tube made of copper in the form of a spiral, the temperature and pressure of freon, according to the laws of physics, decreases, partially evaporating. After the pressure regulator, the mixture of vapor and liquid refrigerant fractions enters the evaporator.

The evaporator converts freon into gaseous form while absorbing heat. The air driven by the fan through the evaporator cools down and is supplied to the room. Gas at low temperature and pressure is sucked back into the compressor. The process is repeated.

Note! The operating principle of the air conditioner is based on the ability of the refrigerant to take away and release heat energy during the transition from the gaseous fraction to the liquid state and vice versa.

Maintenance and repair

It is necessary to regularly clean the air conditioner and carry out preventative maintenance to ensure that all systems are in good working order. You can clean the filter yourself, knowing the design of the model, or call a specialist who can handle it in 30-60 minutes.

If the air conditioner breaks down, do not repair it yourself, call customer service and describe the problem. Sometimes breakdowns are resolved within a few hours on site. For example, if the split system shuts down due to overheating after prolonged operation, the reason most likely lies in the compressor overheating or a dirty radiator. The problem is solved by cleaning the grille.

If the unit is not operating at full capacity, check the air filters. They may need to be cleaned.

Installation features and operating rules

The process of installing a split system is relatively simple, but inexperienced craftsmen should still entrust this mission to professionals familiar with the operation of refrigeration equipment. Usually, the indoor and outdoor units are first installed, a hole is made in the wall and the devices are connected with a pipe.

For the split system to function properly, its filters must be regularly cleaned of contaminants. Excessive equipment heating, voltage surges, and electromagnetic interference should be prevented.

The most important part is filling the system with freon. Even if the owner of the apartment has completed all the other work himself, let an experienced craftsman do this stage; practice shows that this is more reliable.

Improper installation can significantly reduce the efficiency of the air conditioner; it is also the most common cause of breakdowns of this equipment.

It is very important to choose the right location for the indoor unit. If the cold flow is directed to a nearby surface, the equipment will not work correctly, and the cooled air will spread unevenly throughout the room. The operation of the outdoor unit is usually accompanied by the appearance of condensation.

The location for the indoor unit of the split system should be chosen in such a way that there are no obstacles to the free movement of air masses passing through its body

Care should be taken to remove this moisture using a special tube so that the water does not flow down the wall. If the split system is installed correctly, all that remains is to ensure its normal operation. It is recommended to set the cooling temperature within 21-23 degrees.

Lower temperatures are also acceptable, but this operating mode creates additional load on the system. Additionally, too large a difference between the temperature inside and outside a building can have undesirable health consequences.

It is better to install the indoor unit in such a way as to prevent direct exposure to the sun.

Drilling the outer wall when installing a split system is carried out using special equipment, for example, a device for diamond drilling of concrete

In addition to the danger of overheating, there is a possibility that bright light may interfere with the LED signal. To increase the service life of the system, it is better to close windows and doors during operation. Of course, your home needs to be ventilated periodically, or you should purchase a model that takes air from the street.

The equipment should be protected from excessive thermal or electromagnetic influence. Filters should be cleaned every six months. The outdoor unit must be protected from bad weather.

Voltage surges pose a danger to equipment if the difference between nominal and actual values exceeds 15% of the standard.

Customization and management options

The systems under consideration are effective means of climate control. The split system device allows for configuration using a remote control. In this case, the owner of the split system is provided with the following opportunities:

Using the TURBO mode for cases where rapid changes in climatic conditions are required.
A timer that can be used to delay turning on or off the device. It can also be used to set a program of action.

Control panel Source prom.st

If necessary, you can adjust the previously set value for the switching time or the temperature to be reached.
The remote control can be locked. This may be needed in those cases. When there are small children or pets in the house. The lock will prevent the system from being turned on or off accidentally.
Control of horizontal blinds is available. The split system device allows you to change their position in this way, allowing you to redirect the air flow from the system in the desired direction.
It is possible to enable the cleaning mode of the indoor unit.
You can adjust the fan rotation speed.
You can enable or disable the device's quiet mode.

Advantages and disadvantages

Split systems are characterized by the following advantages:

The ability to independently, automatically, maintain the room temperature in a given range.
The ability to create a microclimate that evokes a feeling of comfort.

The split system creates a pleasant indoor climate Source installation-air-conditioners74.rf
See also: Catalog of companies that specialize in ventilation and air conditioning.

Compared to other types of climate control equipment, the case under consideration consumes significantly less electrical energy. Savings can reach 30%.
Split systems operate with virtually no noise.
They are well suited for use in subzero temperatures.
There is a well-designed, convenient control system.

The split system is the creation of completely comfortable climatic conditions regardless of the time of year.

Such systems have a higher cost compared to air conditioners. Their disadvantage is their vulnerability to power surges. To eliminate the possibility of such situations, it is necessary to connect the split system through a voltage stabilizer.

The outdoor module on the outside of the wall slightly spoils the appearance of the building. Therefore, it is more advantageous to place it in other places (for example, on the roof or in the corridor).

External block on the facade of the building Source www.yuga.ru

Review of several interesting models

There are a lot of manufacturers of split systems. Among them are famous brands and small companies. Let's look at a couple of models for orientation.

Hisense AS-10HR4SYDTG

Inexpensive wall-mounted split system. Capable of working on an area of 30 m². It can both cool and heat a room. Additionally, it can simply ventilate the room without changing the temperature. For convenience, there is a remote control and a timer. The maximum declared noise level is 40 dB. The price of a split system is on average about 17,800 rubles.

Hisense AS-10HR4SYDTG

GREEN GRI/GRO-09HH1

You can buy this split air conditioner for about 13,000 rubles. It is a wall-mounted type of placement. Capable of cooling or heating a room of 25 m². There is a ventilation mode, remote control, timer.

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GREEN GRI/GRO-09HH1

Panasonic CS-E9RKDW

Despite the rather high price of this split air conditioning system of 38,000 rubles, its service area is only 15 sq. The fan rotation speed can be set to one of three modes. There are fine air filters, deodorizing filters, warm start and a motion sensor. Judging by the reviews of the split system, this option is perfect for both home and office.

Panasonic CS-E9RKDW

Briefly about the main thing

A split system is a type of air conditioner divided into two units - indoor and outdoor. This is done to increase the comfort of use, because the noisiest part of the device is located on the street.

The split system allows you to create comfortable climatic conditions at home. If necessary, you can cool the air or heat the room.

A convenient control system makes it possible to set a suitable operating mode for a specific period of time.

If necessary, you can use the air circulation mode. In this case, the air in the room will be distributed evenly, creating a feeling of comfort. The split system also allows you to reduce air humidity.

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