Technical characteristics of air conditioners. Functions and characteristics of air conditioners Power consumption of a split system

And here we will talk about the functions and characteristics of the most common type of air conditioners - wall-mounted split systems. Note that most of the described characteristics apply to other types of household and industrial air conditioners.

Air conditioner power consumption

The power consumed by an air conditioner is approximately three times less than the cooling power.

Power consumption is sometimes confused with cooling power. In fact, the power consumed by an air conditioner is about three times less than the cooling power, that is, a 2.5 kW air conditioner consumes only about 800 W - less than an iron or electric kettle. Therefore, household air conditioners, as a rule, can be plugged into a regular outlet without fear of “knocked out” plugs. There is no paradox here, since the air conditioner is a refrigeration machine that does not “produce” cold, but “takes” it from the outside air and transfers it indoors.

The ratio of cooling power to power consumption is the main indicator of the energy efficiency of an air conditioner, which is indicated in technical catalogs by the coefficient ERR(Energy Efficiency Ratio). Another option is COP(Coefficient of Performance - thermal coefficient) is equal to the ratio of heating power to power consumption. The ERR coefficient of household split systems is usually in the range from 2.5 to 3.5, and the COP is from 2.8 to 4.0. You can notice that the COP value is higher than the ERR. This is due to the fact that during operation the compressor heats up and transfers additional heat to the freon. This is why air conditioners always produce more heat than cold. Unscrupulous manufacturers often take advantage of this fact by indicating the COP coefficient instead of the ERR in advertising to confirm the high energy efficiency of their air conditioners. There are seven categories for the energy efficiency of home appliances, lettered from A (best) to G (worst). Air conditioners of category A have COP > 3.6 and ERR > 3.2, and category G have COP< 2.4 и ERR < 2.2.

It should be noted that power consumption and cooling capacity are usually measured according to the ISO 5151 standard (indoor temperature 27°C, outdoor temperature 35°C). If these conditions change, the power and efficiency of the air conditioner will be less (for example, at an outside air temperature of minus 20 ° C, the power of the air conditioner will be only 30% of the nominal value).

What is a “warm” air conditioner or the ability to heat the air?

There are air conditioners that can only cool the air, called only cold and air conditioners with the ability to heat air, called heat - cold, Heat pump, reversible air conditioner or simply " warm" air conditioner. Models with the ability to heat air cost $100-200 more, but in the off-season (autumn and spring) they can replace the heater.

A “warm” air conditioner produces 3–4 times more heat than it consumes electricity, but cannot operate in winter.

Name Heat pump It was not given by chance. It shows that the air conditioner heats the air not with an electric coil or heating element, like an electric heater, but with heat taken from the outside air (heat is pumped from the street to the room). Thus, in the heating mode, the same process occurs as in the cooling mode, only the outdoor and indoor units of the air conditioner seem to change places. Accordingly, in the heating mode, as in the cooling mode, the power consumption is 3 - 4 times less than the heating power, that is, for 1 kW of energy consumed, the air conditioner emits 3 - 4 kW of heat.

Please note that all air conditioners with a heat pump can only operate effectively at positive outside temperatures, so heating with an air conditioner in winter is problematic (more on this below).

Inverter air conditioner

Any properly selected air conditioner can maintain the indoor temperature at 20 - 22°C at an outdoor temperature of 30 - 35°C. If it is not too hot outside, the power of the air conditioner will be excessive, but it is impossible to change it, because the compressor of a conventional (non-inverter) air conditioner has a fixed power. At the same time, to accurately maintain the set temperature, the air conditioner must have variable cooling power. This problem can be solved simply. When the air conditioner is turned on, its sensor constantly monitors the air temperature in the room and when it drops 1 - 2°C below the set value, the compressor turns off. The fan of the indoor unit continues to work, so the compressor shutdown is not noticeable and only appears as a gradual increase in temperature. When it rises 1 - 2°C above the set value, the compressor turns on and the whole cycle repeats. The disadvantage of this technology is the strong fluctuations in indoor temperature, since in order to maintain it more accurately, the compressor would have to be turned on and off too often, and this would lead to rapid wear and tear. Another drawback is that when the compressor is turned on, very cold air begins to blow from the indoor unit - when passing through the evaporator, it is cooled by 13 - 15 ° C. For example, if the current air temperature in the room is 24°C, then the air flow created by the air conditioner will have a temperature of 9 - 11°C, regardless of what temperature is set on the control panel. Being under a direct flow of such cold air is not only uncomfortable, but also dangerous to health.

It was possible to eliminate all these shortcomings only in 1981, when the first inverter air conditioners, having variable cooling (heating) power. The inverter unit in such air conditioners converts the AC supply voltage to DC (this process is called invert), which allows you to smoothly change the compressor speed and thereby regulate the power of the air conditioner. During the operation of an inverter air conditioner, there are no constant on/off cycles of the compressor, so inverter split systems more accurately maintain the set temperature and, as a rule, make less noise. Catalogs for inverter split systems indicate not just one power value, but a range in which it can vary. The wider this range, the more accurately the inverter air conditioner will be able to maintain the set temperature. Therefore, when choosing an inverter split system, you should pay attention not only to the rated power, but also to the ratio of maximum to minimum power - the higher this value, the better.

Air conditioner noise level

If you are planning to install an air conditioner in the bedroom, or if there is a window of nervous neighbors next to the outdoor unit, then you should pay attention to the noise level of the purchased air conditioner. Noise level is measured in Decibels(dB) - a relative unit that shows how many times one sound is louder than another. The audibility threshold is taken as 0 dB (note that sounds with a level of less than 25 dB are actually inaudible). The whisper level is 25 - 30 dB, the noise in an office space, like the volume of a normal conversation, corresponds to 35 - 45 dB, and the noise of a busy street or loud conversation is 50 - 70 dB.

For most household air conditioners, the noise level of the indoor unit is in the range of 26 - 36 dB, of the outdoor unit - 38 - 54 dB. You can notice that the noise of the operating indoor unit does not exceed the noise level of the office premises. Therefore, it makes sense to pay attention to the noise level of the air conditioner if you plan to install it in a quiet room (bedroom, personal office, etc.).

It would seem that now it is enough to choose an air conditioner with the lowest noise level, and comfort is guaranteed. But not everything is so simple: it may turn out that an air conditioner with a noise level of 26 dB will in practice be louder than an air conditioner with a noise level of 32 dB. Moreover, there is no deception here, and all measurements were carried out correctly. Here's the thing. Any air conditioner can operate in several dozen modes, and each mode has its own noise level. Since the main source of indoor unit noise is the air flow through the fan, radiator and distribution louvers, it is logical to measure the noise level at the lowest fan speed and even make this speed as low as possible. The problem is that in this mode the air conditioner will not produce the declared power and in hot weather it will either automatically switch to a higher speed (with increased noise) or will not be able to maintain the set temperature. In a full description of an air conditioner, as a rule, the noise level for all modes of fan operation, or at least the maximum and minimum values, is given. However, the typical noise level of the indoor unit of a premium air conditioner is 27 - 31 - 34 dB for a three-speed fan. In the advertising booklet, only the smallest figure of 27 dB can be given, and not the more correct maximum noise value of 34 dB.

The quietest indoor and outdoor units are in inverter air conditioners in the upper price group.

It should be noted that air conditioners can be a source of not only monotonous noise created by the air flow, but also some other sounds - crackling, hissing, gurgling, clicking. Usually these noises are noticeable only in complete silence, but they can interfere with restful sleep, since sudden sounds are much more annoying than monotonous noise. These sounds are of different nature. Crackling occurs when parts of the plastic case expand and contract due to changes in its temperature. Freon may gurgle and hiss when the compressor is turned on and off. And clicks occur when switching relays that control the operation of the fan, compressor and other air conditioner components. Of all these noises, the greatest discomfort is caused by the cracking of the case - such sounds can even wake you up in the middle of the night. You can recognize a “crackling” indoor unit by its cheap plastic, which in appearance and feel is significantly different from the plastic from which premium air conditioners are made. Inverter air conditioners usually produce less extraneous noise because they do not experience sudden temperature changes associated with periodic turning on and off of the compressor.

If you really need a “quiet” air conditioner, before purchasing, we can advise you to visit several companies that have showrooms with working samples of air conditioners, touch the internal units, listen to how they work in different modes. In general, as a rule, the most “advanced” and expensive air conditioners are also the quietest.

A few words about the outdoor unit. When the windows are closed, otherwise it is not allowed to operate the air conditioner, the noise of the outdoor unit is practically inaudible. But this noise is clearly audible to your neighbors if they themselves do not have air conditioning installed and all the windows are open. Although the noise from the outdoor unit of a working residential air conditioner never exceeds the level allowed for a residential area, the noise can still be very disturbing to residents, especially at night. Note that the difference in the noise level of the external units of air conditioners of the upper and lower price groups is significantly higher than the difference in the noise level of the internal units. Some Daikin split systems even have a “Low-noise outdoor unit” function, when turned on, the noise level of the outdoor unit is halved.

Possibility of ventilation (fresh air supply)

Household split systems cannot supply fresh air to the room. This requires a separate ventilation system.

There is a misconception that any air conditioner can not only cool, but also ventilate the air in the room. However, the fresh air supply function can be fully realized only with duct air conditioners. Conventional wall-mounted split systems can only cool or heat the air inside the room, and the “ventilation” mode, which is written about in the instructions for the air conditioner, means that in this mode only the fan of the indoor unit works, without turning on the compressor.

Basic consumer functions of the air conditioner

To control all modern air conditioners, an infrared remote control with a liquid crystal display is used, which allows you to set the operating mode of the split system, the desired air temperature, program the timer to turn the air conditioner on/off, etc. As a rule, in terms of the number of functions, economy class air conditioners differ little from models in the upper price category. The reason for this unification is that to implement additional capabilities it is not necessary to change or complicate the design of the air conditioner; you just need to reprogram the microcontroller that controls the operation of the air conditioner and add buttons to the remote control.

Thanks to this, manufacturers can inexpensively add new operating modes or additional functions to air conditioners and successfully build their advertising campaigns on their basis. As a result, from the point of view of consumer capabilities, there is often no difference between air conditioners of different price groups. Less common are functions that actually lead to an increase in the cost of the air conditioner, since their implementation requires changes in its design. For example, a built-in motion sensor allows you to save energy, and a temperature sensor in the control panel allows you to maintain a set temperature not in the area of the indoor unit, but where the remote control is located. It’s up to you to decide how necessary these functions are and whether it’s worth overpaying for an air conditioner.

Basic modes and functions of air conditioners:

Cooling And Heating(for “warm” models). The main operating modes of an air conditioner used for air conditioning and heating rooms.
Ventilation. An operating mode in which only the indoor unit fan operates, without turning on the compressor. It is used to distribute air evenly throughout the room and can be used, for example, in winter, when warm air from heaters and central heating radiators accumulates under the ceiling and the floor remains cold.
Auto mode. In this mode, the air conditioner itself controls the selection of operating mode (Cooling, Heating or Ventilation) to maintain a comfortable temperature.
Drainage. In dehumidification mode, the air conditioner reduces air humidity. Generally speaking, dehumidification of air always accompanies its cooling. Warm air comes into contact with the cold heat exchanger (radiator) of the indoor unit, as a result, moisture condenses on the heat exchanger, which is removed through the drain hose. All modern dehumidifiers operate on the same principle. Therefore, in the dehumidifying mode, the air conditioner operates in the same way as in the cooling mode, only the air temperature in the room decreases by no more than 1°C.
Air cleaning. To clean the air, one or more filters are installed in front of the heat exchanger of the indoor unit. The main air conditioner filter is designed to clean the air from large dust (the so-called coarse filter). This filter is a regular fine mesh and protects not so much the occupants of the air-conditioned room as the insides of the air conditioner. To clean this filter, simply rinse it in warm water. Additional filters (so-called fine filters) are designed to clean the air from small dust particles, smoke, and plant pollen. Split systems can be equipped with different fine filters - coal(eliminates unpleasant odors), electrostatic(retains small particles) and others.
Temperature setting. For Cooling and Heating modes, you can control the air temperature with an accuracy of 1°C in the range from 16 - 18 to 30°C. Usually the temperature sensor is installed in the indoor unit of the air conditioner, but some models have an additional sensor built into the remote control. In this case, the user himself chooses at which point the temperature will be measured.
Fan speed. The indoor unit fan can rotate at different speeds, accordingly changing the amount of air passing through the indoor unit (this parameter is called air performance or " pumping» air conditioner and is measured in kb.m./hour). Typically the fan has 3 to 5 fixed speeds plus an automatic mode. In automatic mode, the fan speed is selected based on the current and set temperatures - the more the current temperature differs from the set temperature, the higher the fan speed.
Airflow direction. The direction of the air flow created by the indoor unit can be adjusted vertically using horizontal plates (blinds) having 5 - 7 fixed positions. In cooling mode, the flow is usually directed horizontally along the ceiling to prevent cold air from reaching people. In heating mode, the air flow is directed downward, since hot air is lighter than cold air and rises. In addition, the blinds can automatically swing up and down, evenly distributing the air flow throughout the room. Some models of air conditioners with a power of over 5 kW have automatic vertical blinds that regulate the air flow in the horizontal direction.
Timer to turn on and off. Using the 24-hour timer, you can set the time for the air conditioner to turn on and off automatically, for example, you can turn on the air conditioner an hour before returning from work.
Night mode. After turning on this mode, the air conditioner sets the minimum fan speed (to reduce noise) and smoothly increases (in cooling mode) or decreases (in heating mode) the temperature by 2 - 3 degrees over several hours. It is believed that such temperature conditions are optimal for sleep. 7 hours after this mode is turned on, the air conditioner turns off.

Air conditioner protection systems

Most economy class air conditioners do not have protection systems against improper operation.

If the consumer functions of all air conditioners are the same, then the functions of protection against improper operation or adverse external conditions, on the contrary, differ significantly. A full-fledged air conditioning monitoring and control system involves installing a large number of sensors and additional devices in the external and internal units, which increases the cost of the equipment by 20 - 30%. At the same time, it will not be possible to effectively advertise, say, the presence of a low pressure switch and, accordingly, it will not be possible to get a quick return on the money invested. Therefore, control and protection systems are practically absent in budget air conditioners. Even in the first group, many air conditioners have only partial protection against improper operation.

Basic control and protection systems:

Restart. This function allows the air conditioner to turn on after a power failure. Moreover, the air conditioner will turn on in the same mode in which it was operating before the failure. This simplest function is implemented at the firmware level and is therefore present in almost all air conditioners.
Monitoring the condition of filters. If the filters of the indoor unit of the air conditioner are not cleaned, then in a few months such a layer of dust will accumulate on them that the performance of the air conditioner will decrease several times. As a result, the normal operation of the refrigeration system will be disrupted and liquid freon will flow to the compressor inlet instead of gaseous freon, which will most likely lead to the compressor jamming. But even if the compressor does not fail, over time dust will stick to the radiator plates of the indoor unit, get into the drainage system, and the indoor unit will have to be taken to a service center. That is, the consequences of operating an air conditioner with dirty filters can be very serious. To protect against these consequences, a filter cleanliness monitoring system is built into the air conditioner - when the filters are dirty, the corresponding indicator lights up.
Freon leakage control. In any split system, the amount of freon decreases over time due to normal leakage. This is not dangerous for humans, since freon is an inert gas, but an air conditioner without refueling can only “live” for 2–3 years. The fact is that the air conditioning compressor is cooled by freon and if there is a lack of it, it can overheat and fail. Previously, to turn off the compressor when there was a lack of freon, a low pressure relay was used - when the pressure in the system decreased, this relay turned off the compressor. Now most manufacturers are switching to electronic control systems that measure the temperature at key points in the system and/or compressor current and, based on these data, all operating parameters of the refrigeration system, including freon pressure, are calculated.
Current protection. The compressor current can be used to determine a number of refrigeration system malfunctions. A reduced current indicates that the compressor is operating without load, which means freon has leaked out. An increased current indicates that not gaseous, but liquid freon is supplied to the compressor input, which can be caused either by too low outside air temperatures or dirty filters of the indoor unit. Thus, the compressor current sensor can significantly increase the reliability of the air conditioner.
Automatic defrost. When the outside air temperature is below +5°C, the external unit of the air conditioner may become covered with a layer of frost or ice, which will lead to a deterioration in heat transfer, and sometimes even to breakage of the fan due to the impact of the blades on the ice. To prevent this from happening, the air conditioner control system monitors its operating conditions and, if there is a risk of icing, periodically turns on the auto-defrost system (the air conditioner runs for 5 - 10 minutes in cooling mode without turning on the indoor unit fan, while the heat exchanger of the outdoor unit heats up and thaws).
Low temperature protection. It is strictly not recommended to turn on an unadapted air conditioner at subzero outside temperatures. To prevent breakdowns, some air conditioner models automatically turn off if the outside temperature drops below a certain level (usually minus 5 - 10°C).
Of course, air conditioner protection is not limited to the systems listed above, but we looked at those systems whose presence is very desirable so that the air conditioner takes care of you, and not you of the air conditioner.

Freon type

Freon is a refrigerant, that is, a substance that transfers heat from the indoor unit of a split system to the outdoor unit (more information about this process is written in the section The principle of operation of an air conditioner). Freons (another name is chlorofluorocarbons) are a mixture of methane and ethane, in which hydrogen atoms are replaced by fluorine and chlorine atoms. All refrigerants used in household appliances are non-flammable and harmless to people. There are several types of freon, differing in chemical formulas and physical properties. Freons most often used in air conditioners and refrigerators are R-12, R-22, R-134a, R-407C, R-410A and some others.

Previously, almost all household air conditioners supplied to Russia operated on R-22 freon, which had a low price ($5 per 1 kg) and was easy to use. However, in 2000 - 2003, legislation limiting the use of R-22 freon came into force in most European countries. This was caused by the fact that many freons, including R-22, destroy the ozone layer. To measure the “harmfulness” of freons, a scale was introduced in which the ozone-depleting potential of R-13 freon, which most old refrigerators operate on, was taken as one. The potential of R-22 freon is 0.05, and the new ozone-safe freons R-407C and R-410A are zero. Therefore, to date, most manufacturers focused on the European market have been forced to switch to the production of air conditioners using ozone-safe freons R-407C and R-410A.

For consumers, this transition meant an increase in both the cost of equipment and prices for installation and service work. This was due to the fact that the new freons differ in their properties from the usual R-22:

New freons have a higher condensation pressure - up to 26 atmospheres versus 16 atmospheres for R-22 freon, that is, all elements of the air conditioner refrigeration circuit must be more durable, and therefore more expensive.
Ozone-safe freons are not homogeneous, that is, they consist of a mixture of several simple freons. For example, R-407C consists of three components - R-32, R-134a and R-125. This leads to the fact that even with a slight leak from freon, lighter components evaporate first, changing its composition and physical properties. After this, you have to drain all the freon that has become substandard and refill the air conditioner. In this regard, R-410A freon is more preferable, since it is conditionally isotropic, that is, all its components evaporate at approximately the same rate, and if there is a slight leak, the air conditioner can simply be refilled.
The compressor oil that circulates in the refrigeration circuit along with freon should not be mineral, as is the case with R-22 freon, but polyester. This oil has one significant drawback - it is highly hygroscopic, that is, it quickly absorbs moisture from the atmospheric air. And water that gets into the refrigeration circuit leads to corrosion of its elements and changes in the properties of freon, so it is more difficult to work with such oil.
And most importantly, the cost of new freons is $30-35 per 1 kg, which is 6-7 times more expensive than R-22 freon.

Currently in Moscow you can buy air conditioners that use both new, ozone-safe freons and “classic” R-22. However, all new models of well-known brands use ozone-friendly freons.

Distance between outdoor and indoor units of air conditioner

When placing split system units, it is desirable that the length of inter-unit communications does not exceed 5 - 6 meters, otherwise the cost of installation will increase and the power of the air conditioner will decrease.

The inter-unit distance is of great importance, both for the cost of installing the air conditioner and for its service life. This distance is determined by the length of interblock communications - copper pipes and cables. A standard installation usually includes a 5-meter route - in most cases this is quite enough. In principle, the maximum route length for household air conditioners is 15 - 20 meters (depending on the split system model), however, using a route of this length is not recommended for a number of reasons. Firstly, the cost of installing an air conditioner increases significantly - by 500 - 700 rubles for each additional meter of communications, and if wall chipping is required, then the total cost of each additional meter can increase to 1200 - 1800 rubles. Secondly, as the length of the route increases, the power of the air conditioner decreases and the load on the compressor increases. When placing split system units, it is also necessary to take into account restrictions on the height difference between the indoor and outdoor units (usually 7 - 10 meters).

Oddly enough, but a route that is too short can also lead to problems. Freon pipes connecting the indoor and outdoor units of a split system are an element of the refrigeration circuit, so any deviation in the length of communications from the calculated 5 meters will lead to a change in the parameters of the refrigeration cycle. Even if the blocks of the split system are located only 1 meter from each other, the length of the route should be about 5 meters (its excess is rolled up into a ring, which is hidden behind the outdoor block). Note that budget air conditioners are more sensitive to deviations of the route length from the optimal value, since they have a simplified monitoring and control system.

If the length of the route exceeds 15 - 20 meters, then you will have to use not a household, but a semi-industrial air conditioner. For example, the semi-industrial series of wall-mounted split systems FDKN Mitsubishi Heavy is designed for a route length of up to 30 meters with a height difference of up to 20 meters. And multi-zone VRV systems allow blocks to be spaced 150 meters apart with a 50-meter height difference.

The influence of temperature on the operation of the air conditioner

A correctly selected air conditioner is able to set and maintain a comfortable indoor air temperature - usually from +18°C to +28°C. The outside air temperature is more complicated.

For cooling mode: the lower limit is from -5°C to +18°C for various models, the upper limit is about +43°C.

For heating mode: the lower limit is from -5°C to +5°C for various models, the upper limit is about +21°C.

The significant spread in the lower temperature limit is explained by the fact that to ensure normal operation of the air conditioner in a wide temperature range, it is necessary to install additional sensors and complicate the air conditioner circuit, and this increases its cost. If you plan to turn on the air conditioner for cooling when the outside air temperature is below +15°C, then we advise you to pay attention to the operating range of the selected model. The operating temperature range is always indicated in technical catalogs or in the user manual. Operating the air conditioner at temperatures below the permissible temperature leads to unstable operation and freezing of the radiator of the indoor unit, as a result of which water may drip from the air conditioner.

The difference between air conditioners of the first and third groups is manifested in the operating range of outside air temperatures - stable operation at temperatures from -5°C to +40°C is possible only with a high-quality and expensive control system. Most air conditioners are not designed to operate at outdoor temperatures below -5°C.

If the outside air temperature drops below -5°C, then turning on the air conditioner is strictly not recommended. At low temperatures, the physical properties of freon and compressor oil change. As a result, at startup, a cold compressor may jam and will have to be replaced. But even in the case of a successful start-up, compressor wear will be significantly higher than permissible. Therefore, operating an air conditioner in winter will inevitably lead to failure of the compressor within 2 to 3 years. In addition, at sub-zero temperatures, the drain hole of the drainage hose freezes and when working for cooling, all the condensate begins to flow into the room.

However, it's not all bad. Many manufacturers have air conditioners adapted to winter operating conditions. How these split systems differ from their non-adapted counterparts is in the next paragraph.

Additional devices

All-season block

An all-season unit allows the air conditioner to operate at outdoor temperatures down to minus 20 - 30°C, but at the same time the cost of the air conditioner increases by $150 - 200.

So that the air conditioner can work in winter, an additional device is built into it - all-season block or winter set, which heats the drainage and compressor crankcase, and also controls the operation of the outdoor unit fan. In this case, the air conditioner can operate at low outside temperatures (usually up to -15°C ... -30°C). It must be taken into account that even with an adapted air conditioner, when the temperature drops, the efficiency and cooling / heating power decreases. At -20°C, the efficiency of the air conditioner drops by approximately three times compared to the nominal value. Therefore, in winter it is better to use heaters for heating, which are also ten times cheaper than an air conditioner. You can use an unadapted air conditioner for heating only in the off-season - in autumn and spring, when the heating has not yet been turned on or has already been turned off.

An air conditioner with a winter kit can be useful in two cases. Firstly, to increase the reliability of the air conditioner. In this case, you can adapt almost any split system. Adaptation will allow you to turn on the air conditioner at any time of the year without fear of puddles on the floor or compressor failure. Secondly, a “winter air conditioner” will be simply necessary in rooms with a lot of heat-producing equipment, for example in server rooms, for cooling not only in summer, but also in winter. Since cold outdoor air contains little moisture, cooling such a room using the “window” method reduces air humidity to 20 - 30% (with an optimal value of 55%), which negatively affects not only people, but also complex electronic equipment. Therefore, the only option for air conditioning a server room is to use an adapted air conditioner. An air conditioner with a factory adaptation of the first reliability group is best suited as an air conditioner for a server room.

Drainage pump

During operation of any air conditioner, water forms on the surface of the evaporator (radiator of the indoor unit). It condenses when the air passing through the evaporator cools and flows into a tray located under the evaporator. From the pan, water is removed from the air conditioner through a drain hose. Usually the drainage hose is led out into the street through a hole in the outer wall; less often, the drain is discharged into the sewer. In any case, the drainage drain hole must be below the level of the pan so that water can flow freely from the air conditioner under the influence of gravity.

However, there are cases when the drainage outlet has to be located above the level of the sump, for example, when installing an air conditioner in the basement. In such a situation, it is necessary to use a drainage pump that can raise the water to a certain height. Structurally, the pump is made in the form of a small rectangular block in which the pump and a miniature tank with a water sensor are located. When the tank is filled with water, the sensor turns on the pump, the water is pumped out, after which the pump turns off and the cycle repeats. Installing a pump leads not only to an increase in the cost of the air conditioner, but also to a noticeable increase in the noise level. Therefore, it is advisable to install air conditioning in apartments so that you do not have to use a drainage pump.

Protective visor

Sometimes, when installing the outdoor unit of a split system, a metal canopy is installed above it. The main purpose of the visor is to protect the outdoor unit from falling icicles and snow while cleaning the roof. However, when installing an air conditioner with a visor, you will most likely have to use the services of an industrial climber. In this case, the outdoor unit will have to be lowered 25 - 30 centimeters lower than usual and it will become impossible to mount it from the window. For the same reason, it is usually impossible to install a canopy over an already mounted unit without dismantling/installing it.

Protective box (grid)

A protective box or grille is installed to protect the outdoor unit from vandalism or theft. This box is a rectangular frame covered with a metal mesh and covers the outdoor unit on all sides except the bottom (bottom access is required for service). Such protection is used in cases where the outdoor unit is installed in an easily accessible place - at a low height, on the roof, etc.

Which air conditioner should you choose?

The power of the air conditioner is determined based on calculation and does not depend on our desires and preferences. An attempt to save money and buy an air conditioner of lower power can be justified only if there is a small (10 - 15%) deviation from the calculated value.
By choosing an air conditioner with the ability to heat the air and spending an additional $100 - $150, you can stay warm in the fall and spring while saving 65% on energy. However, remember that for the same money you can buy a good heater that can also heat in winter. According to statistics, “warm” air conditioners are purchased several times more than “cold” ones.
An air conditioner using ozone-safe freon has a price that is 10-15% higher compared to a similar model using R-22 freon, and the cost of installing such an air conditioner increases by 20-30%. At the same time, the use of ozone-safe freon does not in any way affect the consumer properties of the air conditioner.
An inverter air conditioner saves energy, maintains the set temperature more accurately and makes less noise. At the same time, it is significantly more difficult to produce. Therefore, we do not recommend buying inverters of “national” brands. It’s better to buy a regular air conditioner of the first or second group for the same money - it will be more reliable.
Since domestic air conditioners do not have the ability to ventilate air, a supply ventilation system is required to create comfortable conditions in air-conditioned rooms. Otherwise, you will have to periodically open the window to ventilate the room.
The consumer functions of all air conditioners are approximately the same, so when choosing an air conditioner, it is better to pay attention to its reliability and the presence of protection systems against improper operation and adverse external conditions.
Modern household air conditioners have a low enough noise level that in most cases you do not pay attention to this parameter. If you still need the quietest air conditioner, choose a well-known Japanese brand (Daikin, Mitsubishi, Fujitsu, Panasonic). In this case, you will be guaranteed a minimum noise level from both the indoor and outdoor units.
Restrictions on the temperature range of outside air, inherent in all inexpensive air conditioners, do not play a big role in domestic conditions, since in cooling mode the air conditioner is used only if the temperature outside the window exceeds 20°C. If you need stable operation of the air conditioner over a wide temperature range, then it is better to choose a model specially adapted to winter conditions.
When planning the placement of split system units, try to minimize the length of inter-unit communications. In a typical installation of an air conditioner (external unit under the window, internal unit not far from the window), the length of the route does not exceed 5 meters. If the length of the route is more than 7 meters, then it is advisable not to use “budget” air conditioners (LG, Samsung, Midea and similar).

The power consumed by an air conditioner is approximately three times less than the cooling power.

The power consumed by an air conditioner is sometimes confused with cooling power. In reality, the power consumption is about three times less than the cooling power, meaning a 2.5 kW model consumes about 800 W - less than an iron or kettle. Therefore, household air conditioners with a cooling power of up to 4 kW can be plugged into a regular outlet without fear of broken plugs. There is no paradox here, because an air conditioner is a refrigeration machine that does not “produce” cold, but “takes” it from the outside air and transfers it into the room.

Air conditioner energy efficiency, EER and COP coefficients

The energy efficiency of an air conditioner is determined by how many times its cooling power is greater than its power consumption. The coefficient equal to the ratio of these two parameters is called EER(Energy Efficiency Ratio). Another coefficient - COP(Coefficient of Performance) shows the efficiency of the air conditioner in heating mode and is equal to the ratio of heating power to power consumption. The value of the EER coefficient of household split systems usually lies in the range from 2,5 before 3,5 , and COP - from 2,8 before 4,0 (for modern inverter models, ERR and COP can reach 4.5-5.0). It can be observed that on average the COP value is greater than the EER. This is due to the fact that during operation the compressor heats up and transfers excess heat to freon, so air conditioners produce more heat than cold. Manufacturers sometimes take advantage of this fact by indicating only the COP coefficient in advertising to confirm the high energy efficiency of their split systems.

To make it easier for buyers to compare the energy efficiency of different models, an energy efficiency scale was introduced for air conditioners, as well as for other household appliances, consisting of seven categories, designated by letters from A(best) to G(worst). Category G air conditioners have COP< 2,4 и EER < 2,2, а категории A — COP >3.6 and EER > 3.2.

Seasonal SEER and SCOP coefficients

The air conditioner parameters for calculating EER and COP are measured under strictly defined conditions in accordance with the ISO 5151 standard (air conditioner operating at maximum power, outside air temperature +35°C in cooling mode or +7°C in heating mode). In real conditions, the energy efficiency of an air conditioner is usually lower. So that consumers can estimate the actual energy consumption of the air conditioner and compare different models based on this parameter, seasonal coefficients were introduced SEER(Seasonal Energy Efficiency Ratio) and SCOP(Seasonal Coefficient of Performance). To calculate these coefficients, the amount of cold or heat produced by the air conditioner in one season is determined, which is divided by the electricity consumed during the same period. To more accurately take into account the dependence of energy efficiency on outdoor temperature, the SCOP coefficient is calculated separately for different climatic zones. Since 2013, a new type of stickers applied to air conditioners has been introduced on the European market. Instead of EER and COP, they indicate seasonal coefficients, and SCOP can be indicated for three European climate zones (for now it is mandatory to indicate it only for the middle zone, which is tied to the climate of Strasbourg). Based on seasonal coefficients, a new scale of energy efficiency of air conditioners has been developed from D(SEER< 3,6; SCOP<2,5) до A+++(SEER > 8.5; SCOP > 5.1). These innovations are described in more detail in the brochure (excerpt from the Mitsubishi Electric catalogue).

You have probably already noticed that the values of the seasonal SEER and SCOP coefficients are greater than the traditional EER and COP, although it should be the other way around. The fact is that seasonal coefficients began to be used for the first time in the United States, where not the traditional kW, but BTU/hour is used to indicate cooling capacity. Therefore, when determining seasonal coefficients, the amount of cold or heat is measured in BTU/hour, but the energy consumed is measured in the usual Watts. Since 1 W ≈ 3.41 BTU/hour, the seasonal coefficients turned out to be approximately 3,4 times higher than the values we would get if we measured the cooling power in Watts, as is done when calculating EER and COP. You can also notice that SEER > SCOP (EER and COP had an inverse relationship). This is due to the fact that in real conditions SCOP is measured in the cold season, and at low outside temperatures the energy efficiency of the air conditioner decreases noticeably.

How much will you have to pay for electricity?

When calculating seasonal coefficients, another very important parameter for the consumer is determined, the value of which is also indicated on the sticker. This is the total amount of electricity consumed by the air conditioner per year (separately for cooling and heating modes) - kWh/annum. If we multiply this number by the cost of kWh, we get the annual cost of the electricity consumed by the air conditioner. You just need to take into account that the calculation method assumes economical cooling according to European standards: the indoor air temperature is set at +26.7°C (ARI Standard 210/240). Therefore, in practice, energy consumption will most likely be more than indicated on the sticker. You can also estimate the cost of electricity consumed per season in different weather conditions using.

What is an inverter air conditioner?

Perhaps the most important difference between some split system models and others is the presence or absence of an inverter - an electronic module located in the outdoor unit, which allows you to smoothly change the compressor speed. Let's see how inverter air conditioners differ from conventional models from a practical point of view.

A case from practice: a customer (let's call him Vasily) complains that when he sets the remote control to 22°C he feels cold, but at 23°C he feels hot, and asks to find him an air conditioner in which he can set the temperature to 22.5°C. What actually happens is that when the temperature is set to 22°C, the air conditioner begins to cool the room to 20-21°C. As the temperature in the room drops, the temperature of the air flow at the outlet of the air conditioner also drops, and at some point Vasily freezes, after which he increases the temperature to 23°C. If at this moment the room is already about 23°C, the compressor will turn off and warm air will begin to blow from the air conditioner. Vasily will become hot and he will reduce the temperature by 1°C, the compressor will turn on and Vasily will freeze.

Any properly selected air conditioner can maintain the indoor temperature at 20-22°C at an outdoor temperature of 30-35°C. If it is not too hot outside, the power of the air conditioner will be excessive, but it is impossible to change it, because the compressor of a conventional (non-inverter) air conditioner has a fixed power. At the same time, to accurately maintain the set temperature, the air conditioner must have variable cooling power. This problem can be solved simply. When the air conditioner is turned on, the temperature sensor constantly monitors the air temperature in the room, and when it drops 1-2°C below the set value, the compressor turns off. The fan of the indoor unit continues to work, so the compressor shutdown is not noticeable and only appears as a gradual increase in temperature. When it rises 1-2°C above the set value, the compressor turns on and the whole cycle repeats. The disadvantage of this technology is the strong fluctuations in indoor temperature, since in order to maintain it more accurately, the compressor would have to be turned on and off too often, and this would lead to rapid wear and tear. Another drawback is that when the compressor is turned on, very cold air begins to blow from the indoor unit - when passing through the evaporator, it is cooled by 13-15 ° C. If, for example, the current air temperature in the room is 24°C, then the air flow created by the air conditioner will have a temperature of 9-11°C, regardless of what temperature is set on the control panel. Being close to a flow of such cold air is not only uncomfortable, but also dangerous to health.

It was possible to eliminate this fundamental drawback only in 1981, when the first inverter air conditioners, having variable cooling (heating) power. The inverter unit in such air conditioners converts the alternating supply voltage into direct voltage, which allows you to smoothly change the compressor speed, thereby regulating the power of the air conditioner and the temperature difference at the input and output of the indoor unit.

If the room is hot, the compressor runs at higher speeds and the air conditioner quickly cools the room to a comfortable level. However, then the compressor does not turn off, but reduces the speed, due to which the air flow at the outlet of the air conditioner becomes only slightly colder than the air in the room. It is this feature of inverter models that allows us to say that they create more comfortable conditions and more accurately maintain the set temperature. In addition, such air conditioners consume less electricity (30-50%) and make less noise.

Catalogs for inverter models usually indicate not one power value, but a range in which it can vary. The wider this range, the more accurately the air conditioner will be able to maintain the set temperature.

Possibility of heating (heat-cold air conditioners)

There are air conditioners that can only cool the air, called only cold and air conditioners with the ability to heat air, called warm - cold, Heat pump, reversible air conditioner or simply " warm" air conditioner. Models with the ability to heat air are 10-15% more expensive, but in the off-season (autumn and spring) they can replace the heater.

A “warm” air conditioner produces 3-4 times more heat than it consumes electricity, but usually cannot operate at low outside temperatures.

Name Heat pump It was not given by chance. It shows that the air conditioner heats the air not with an electric coil or heating element, like an electric heater, but with heat taken from the outside air (heat is pumped from the street to the room). Thus, in the heating mode, the same process occurs as in the cooling mode, only the outdoor and indoor units of the air conditioner seem to change places. Accordingly, in the heating mode, as in the cooling mode, the power consumption is 3-4 times less than the heating power, that is, for 1 kW of energy consumed, the air conditioner emits 3-4 kW of heat.

Please note that all heat pump air conditioners can operate effectively only at positive outside temperatures, so heating with an air conditioner in winter is problematic (read more about this). The only exceptions are special models of air conditioners and heat pumps designed to operate at low air temperatures (for example, the Zubadan Mitsubishi Electric series).

Air conditioner noise level

The quietest indoor and outdoor units are in inverter air conditioners in the upper price group.

If you are planning to install an air conditioner in the bedroom or have a window of nervous neighbors next to the outdoor unit, then we recommend paying attention to the noise level of the purchased air conditioner. Noise level is measured in decibels (dB), a relative unit that shows how many times one sound is louder than another. The threshold of audibility is taken to be 0 dB (note that in this case sounds with a level of less than 20 dB are actually inaudible). The whisper level is 25-30 dB, the noise in an office space, like the volume of a normal conversation, corresponds to 35-45 dB, and the noise of a busy street or loud conversation is 50-70 dB.

For most household air conditioners, the noise level of the indoor unit is in the range of 22-35 dB, and the noise level of the outdoor unit is 38-54 dB. You can notice that the noise of the operating indoor unit does not exceed the noise level of the office premises. Therefore, it makes sense to pay attention to this parameter if you plan to install the air conditioner in a quiet room (bedroom, personal office, etc.).

It would seem that now it is enough to choose an air conditioner with the lowest noise level and comfort is guaranteed. But not everything is so simple: it may turn out that an air conditioner with a noise level of 24 dB will in practice be louder than an air conditioner with a noise level of 26 dB. Moreover, there is no deception here, and all measurements were made correctly. There may be several reasons for this:

Firstly, different manufacturers may use different noise measurement techniques, which significantly affects the results obtained. For example, the distance to the measuring microphone, according to different standards, can be from one to three meters.
Secondly, the air conditioner can operate in several modes, and each mode has its own noise level. Since the main source of indoor unit noise is the air flow passing through the radiator-fan-distribution louvers system, it is beneficial for manufacturers to measure the noise level at the lowest fan speed, and even make the minimum speed as low as possible. The problem is that in hot weather, an air conditioner operating at minimum speed will not be able to maintain a comfortable temperature and will automatically increase the fan speed. The description of the air conditioner, as a rule, provides the noise level for all fan operating modes or at least the values for minimum and maximum speeds. The typical noise level of a premium air conditioner indoor unit is 23-29-32 dB for a three-speed fan. In the advertising booklet, only one value can be given - 23 dB.
Thirdly, air conditioners can be a source of not only monotonous noise created by the air flow, but also some other sounds: crackling, hissing, gurgling, clicking. Usually these noises are noticeable only in complete silence, but they can interfere with restful sleep, since even quiet, but sudden sounds are much more annoying than monotonous noise. These sounds are of different nature. Crackling occurs when parts of the plastic case expand and contract due to changes in its temperature. Freon may gurgle and hiss when the compressor is turned on and off. And clicks occur when switching relays that control the operation of the fan, compressor and other air conditioner components. Of all these noises, the greatest discomfort is caused by the cracking of the case. You can recognize a “crackling” indoor unit by its cheap plastic, which differs in appearance and feel from the plastic from which premium air conditioners are made. When you press on such a housing, it begins to creak noticeably. Inverter air conditioners produce less noise because they do not experience sudden temperature changes associated with periodic turning on and off of the compressor.

There may also be problems with noise from the outdoor unit. When the windows are closed, otherwise it is not recommended to operate the air conditioner, the noise of the outdoor unit is practically inaudible. But this noise is clearly audible to your neighbors if they themselves do not have air conditioning installed and all the windows are open. Although the noise from the outdoor unit of a working residential air conditioner never exceeds the level allowed for a residential area, the noise can still be very disturbing to residents, especially at night. Note that the difference in the noise level of the external units of air conditioners of the upper and lower price groups is significantly higher than the difference in the noise level of the internal units. Some premium split systems even have a “Low Noise Outdoor Unit” function, when turned on, the noise level of the outdoor unit is reduced.

Possibility of ventilation (fresh air supply)

Household split systems cannot supply fresh air to the room. This requires a separate ventilation system.

There is a misconception that any air conditioner can not only cool, but also ventilate the air in the room. However, the fresh air supply function can be fully realized only with. Conventional wall-mounted split systems can only cool or heat the air inside the room, and the “ventilation” mode, which is written about in the instructions for the air conditioner, means that in this mode only the fan of the indoor unit works, without turning on the compressor.

It should be noted that recently several models of household split systems with the function of supplying fresh air have appeared (for example, the Ururu-Sarara Daikin series, supply up to 32 m³/h), however, their productivity is low, and the cost is comparable to the cost of an air supply unit, allowing create a complete air ventilation system.

Basic consumer functions of the air conditioner

Basic modes and functions of air conditioners:

Air conditioner protection systems

Most economy class air conditioners do not have protection systems against improper operation.

If the consumer functions of all air conditioners are the same, then the functions of protection against improper operation or adverse external conditions, on the contrary, differ significantly. A full-fledged air conditioner monitoring and control system involves installing a large number of sensors and additional devices in the external and internal units, which increases the cost of the equipment by 20–30%. At the same time, it will not be possible to effectively advertise, say, the presence of a low pressure switch and, accordingly, it will not be possible to get a quick return on the money invested. Therefore, control and protection systems are practically absent in budget air conditioners. Even in the first group, many air conditioners have only partial protection against improper operation.

Basic control and protection systems:

Restart. This function allows the air conditioner to turn on after a power failure. Moreover, the air conditioner will turn on in the same mode in which it was operating before the failure. This simplest function is implemented at the firmware level and is therefore present in almost all air conditioners.
Monitoring the condition of filters. If the filters of the indoor unit of the air conditioner are not cleaned, then in a few months such a layer of dust will accumulate on them that the performance of the air conditioner will decrease several times. As a result, the normal operation of the refrigeration system will be disrupted and liquid freon will flow to the compressor inlet instead of gaseous freon, which will most likely lead to the compressor jamming. But even if the compressor does not fail, over time dust will stick to the radiator plates of the indoor unit, get into the drainage system, and the indoor unit will have to be taken to a service center. That is, the consequences of operating an air conditioner with dirty filters can be very serious. To protect against these consequences, a filter cleanliness monitoring system is built into the air conditioner; when the filters are dirty, the corresponding indicator lights up.
Freon leakage control. In any split system, the amount of freon decreases over time due to normal leakage. This is not dangerous for humans, since freon is an inert gas, but an air conditioner can only “live” for 2–3 years without refueling. The fact is that the air conditioning compressor is cooled by freon and if there is a lack of it, it can overheat and fail. Previously, a low pressure relay was used to turn off the compressor when there was a lack of freon; when the pressure in the system decreased, this relay turned off the compressor. Now most manufacturers are switching to electronic control systems that measure the temperature at key points in the system and/or compressor current and, based on these data, all operating parameters of the refrigeration system, including freon pressure, are calculated.
Current protection. The compressor current can be used to determine a number of refrigeration system malfunctions. A reduced current indicates that the compressor is operating without load; this means freon has leaked out. An increased current indicates that not gaseous, but liquid freon is supplied to the compressor input, which can be caused either by too low outside air temperatures or dirty filters of the indoor unit. Thus, the compressor current sensor can significantly increase the reliability of the air conditioner.
Automatic defrost. When the outside air temperature is below +5°C, the external unit of the air conditioner may become covered with a layer of frost or ice, which will lead to a deterioration in heat transfer, and sometimes even to breakage of the fan due to the impact of the blades on the ice. To prevent this from happening, the air conditioner control system monitors its operating conditions and, if there is a risk of icing, periodically turns on the auto-defrost system (the air conditioner runs for 5–10 minutes in cooling mode without turning on the indoor unit fan, while the heat exchanger of the outdoor unit heats up and thaws).
Low temperature protection. It is strictly not recommended to turn on an unadapted air conditioner at subzero outside temperatures. To prevent breakdowns, some air conditioner models automatically turn off if the outside temperature drops below a certain level (usually minus 5–10°C).
Of course, air conditioner protection is not limited to the systems listed above, but we looked at those systems whose presence is very desirable so that the air conditioner takes care of you, and not you of the air conditioner.

Freon type

Freon is a refrigerant, that is, a substance that transfers heat from the indoor unit of a split system to the outdoor unit (more information about this process is written in the section). Freons (another name for them are chlorofluorocarbons) are a mixture of methane and ethane, in which hydrogen atoms are replaced by fluorine and chlorine atoms. All refrigerants used in household appliances are non-flammable and harmless to people. There are several types of freon, differing in chemical formulas and physical properties. Freons most often used in air conditioners and refrigerators are R-12, R-22, R-134a, R-407C, R-410A and some others.

Previously, almost all household air conditioners supplied to Russia operated on R-22 freon, which had a low price ($5 per 1 kg) and was easy to use. However, in 2000–2003, legislation restricting the use of R-22 freon came into force in most European countries. This was caused by the fact that many freons, including R-22, destroy the ozone layer. To measure the “harmfulness” of freons, a scale was introduced in which the ozone-depleting potential of R-13 freon, which most old refrigerators operate on, was taken as one. The potential of freon R-22 is 0.05, and the potential of new ozone-safe freons R-407C and R-410A is zero. Therefore, by 2003, most manufacturers focused on the European market were forced to switch to the production of air conditioners using ozone-friendly freons R-407C and R-410A.

New freons have a higher condensation pressure - up to 26 atmospheres versus 16 atmospheres for R-22 freon, that is, all elements of the air conditioner refrigeration circuit must be more durable, and therefore more expensive.
Ozone-safe freons are not homogeneous, that is, they consist of a mixture of several simple freons. For example, R-407C consists of three components R-32, R-134a and R-125. This leads to the fact that even with a slight leak from freon, lighter components evaporate first, changing its composition and physical properties. After this, you have to drain all the freon that has become substandard and refill the air conditioner. In this regard, R-410A freon is more preferable, since it is conditionally isotropic, that is, all its components evaporate at approximately the same rate, and if there is a slight leak, the air conditioner can simply be refilled.
The compressor oil that circulates in the refrigeration circuit along with freon should not be mineral, as is the case with R-22 freon, but polyester. This oil has one significant drawback - it is highly hygroscopic, that is, it quickly absorbs moisture from the atmospheric air. And water that gets into the refrigeration circuit leads to corrosion of its elements and changes in the properties of freon, so it is more difficult to work with such oil.
And most importantly, the cost of new freons is $30–35 per 1 kg, which is 6-7 times more expensive than R-22 freon.

Since 2013, the import into the territory of the Customs Union (and therefore into Russia) not only of R-22 freon, but also of products containing it, has been prohibited. Therefore, it is now almost impossible to buy an air conditioner using R-22 freon.

Distance between outdoor and indoor units of air conditioner

The inter-unit distance is of great importance, both for the cost of installing the air conditioner and for its service life. This distance is determined by the length of interblock communications copper pipes and cables. A standard installation usually includes a 5-meter route; in most cases this is quite enough. In principle, the maximum route length for household air conditioners is 15–20 meters (depending on the split system model), however, using a route of this length is not recommended for a number of reasons. Firstly, the cost of installing an air conditioner increases significantly by 500–700 rubles for each additional meter of communications, and if wall chipping is required, then the total cost of each additional meter can increase to 1200–1800 rubles. Secondly, as the length of the route increases, the power of the air conditioner decreases and the load on the compressor increases. When placing split system units, it is also necessary to take into account restrictions on the height difference between the indoor and outdoor units (usually 7–10 meters).

If the length of the route exceeds 15–20 meters, then you will have to use not a household, but a semi-industrial air conditioner. For example, the semi-industrial series of wall-mounted split systems FDKN Mitsubishi Heavy is designed for a route length of up to 30 meters with a height difference of up to 20 meters. And multizonal ones allow blocks to be spaced 150 meters apart with a 50-meter height difference.

The influence of temperature on the operation of the air conditioner

The efficiency of the air conditioner is greatly influenced by the outside temperature. For each model, the documentation indicates the permissible operating temperature range:

For the cooling mode, the lower limit is in the range from -5°C to +18°C for various models, the upper limit is around +43°C.
For the heating mode, the lower limit is in the range from -5°C to +5°C for various models, the upper limit is around +21°C.

If the outside air temperature drops below -5°C, then turning on the air conditioner is strictly not recommended. At low temperatures, the physical properties of freon and compressor oil change. As a result, at startup, a cold compressor may jam and will have to be replaced. But even in the case of a successful start-up, compressor wear will be significantly higher than permissible. Therefore, operating an air conditioner in winter will inevitably lead to failure of the compressor within 2–3 years. In addition, at sub-zero temperatures, the drain hole of the drainage hose freezes and when working for cooling, all the condensate begins to flow into the room.

Additional devices

All-season block

An all-season unit allows the air conditioner to operate at outdoor temperatures down to minus 20-30°C, but at the same time the cost of the air conditioner increases by 3-4 thousand rubles.

So that the air conditioner can operate in winter, an additional device is built into it all-season block or winter set, which heats the drainage and compressor crankcase, and also controls the operation of the outdoor unit fan. In this case, the air conditioner can operate at low outside temperatures (usually up to -15°C -30°C). It must be taken into account that even with an adapted air conditioner, when the temperature drops, the efficiency and cooling / heating power decreases. At -20°C, the efficiency of the air conditioner drops by approximately three times compared to the nominal value. Therefore, in winter it is better to use heaters for heating, which are also ten times cheaper than an air conditioner. You can use an unadapted air conditioner for heating only in the off-season - in autumn and spring, when the heating has not yet been turned on or has already been turned off.

An air conditioner with a winter kit can be useful in two cases. Firstly, to increase the reliability of the air conditioner. In this case, you can adapt almost any split system. Adaptation will allow you to turn on the air conditioner at any time of the year without fear of puddles on the floor or compressor failure. Secondly, a “winter air conditioner” will be simply necessary in rooms with a lot of heat-producing equipment, for example in server rooms, for cooling not only in summer, but also in winter. Since cold outdoor air contains little moisture, cooling such a room using the “window” method reduces air humidity to 20–30% (with an optimal value of 55%), which negatively affects not only people, but also complex electronic equipment. Therefore, an adapted air conditioner is usually used to air condition a server room, although for reasons of economy, a freecooling system can also be used. As an air conditioner for a server room, a model with factory adaptation of the first reliability group is best suited.

Drainage pump

Compact pumps for household split systems can be placed behind the air conditioner (in a niche for freon tubes) or in a box near the indoor unit (some pump models are equipped with a specially sized decorative box). More powerful (high-flow or high-pressure) pumps are too large to be hidden behind the air conditioner, so they usually have a decorative housing that allows them to be placed near the indoor unit.

It must be taken into account that the use of a pump leads to a noticeable increase in noise level.

Protective visor

A metal protective canopy is installed above the outdoor unit and protects it from falling icicles, snow when cleaning the roof and objects that residents of the upper floors can throw out the window.

The distance between the air conditioner unit and the visor must be at least 10-15 centimeters: this deformation zone of the visor will allow you to save the air conditioner if a heavy object falls from above. This means that if the outdoor unit is installed under a window, the upper edge of the unit should be located 20-25 centimeters below the window sill, otherwise there will be nowhere to attach the visor. In order to install an outdoor unit at this level, you will most likely have to use the services of an industrial climber. For the same reason, it is most often impossible to correctly install a canopy over an already mounted unit without dismantling/installing it.

Protective box (grid)

The upper part of the box is usually made of sheet metal, so the box also protects the air conditioner from falling heavy objects, that is, it acts as a protective canopy.

Screen for indoor unit

The air flow from the indoor unit cannot always be directed parallel to the floor; it is usually directed at a slight downward angle. If there is a workplace near the air conditioner, the flow of cold air may hit a person. To prevent this from happening, you can install a transparent (so as not to disturb the interior of the room) reflective screen under the indoor unit, which will deflect the flow upward to the ceiling to evenly distribute cold air throughout the room.

There are screens that do not require installation: they are attached directly to the indoor unit using transparent plastic brackets and double-sided tape.

Which air conditioner should you choose?

The power of the air conditioner is determined based on calculation and does not depend on our desires and preferences. An attempt to save money and buy an air conditioner of lower power can be justified only if there is a small (10–15%) deviation from the calculated value.
By choosing an air conditioner with the ability to heat the air, you can warm up in the fall and spring, while saving 65% of energy. According to statistics, “warm” air conditioners are purchased several times more than “cold” ones.
An inverter air conditioner saves energy, maintains the set temperature more accurately and makes less noise. At the same time, it is significantly more difficult to produce. Therefore, we do not recommend buying inverters of “national” brands. It’s better to buy a regular air conditioner of the first or second group for the same money; it will be more reliable.
Since domestic air conditioners do not have the ability to ventilate air, a supply ventilation system is required to create comfortable conditions in air-conditioned rooms. Otherwise, you will have to periodically open the window to ventilate the room.
The consumer functions of all air conditioners are approximately the same, so when choosing an air conditioner, it is better to pay attention to its reliability and the presence of protection systems against improper operation and adverse external conditions.
Modern household air conditioners have a low enough noise level that in most cases you do not pay attention to this parameter. If you still need the quietest air conditioner, choose a well-known Japanese brand (Daikin, Mitsubishi, Fujitsu, Panasonic). In this case, you will be guaranteed a minimum noise level from both the indoor and outdoor units.
Restrictions on the temperature range of outside air, inherent in all inexpensive air conditioners, do not play a big role in domestic conditions, since in cooling mode the air conditioner is used only if the temperature outside the window exceeds 20°C. If you need stable operation of the air conditioner over a wide temperature range, then it is better to choose a model specially adapted to winter conditions.
When planning the placement of split system units, try to minimize the length of inter-unit communications. In a typical installation of an air conditioner (outdoor unit under the window, indoor unit not far from the window), the length of the route does not exceed 5 meters. If the length of the route is more than 7 meters, then it is advisable not to use “budget” air conditioners (LG, Samsung, Midea and similar).

Modern air conditioners not only protect our home from heat, they can also clean and heat the air. In this article we will tell you how to choose an air conditioner for your home or office, and how not to pay for unnecessary device options. After familiarizing yourself with the characteristics of various air conditioners, you can purchase the device that is right for you.

What types of air conditioners are there?

According to this application parameter, air conditioners are divided into:

domestic air conditioners;
semi-industrial air conditioners;
industrial ventilation air conditioners.

Let's leave the choice of industrial units to the specialists, and let's focus on the properties and technical parameters of household (home) air conditioners. There are three types of household air conditioners:

Monobloc design– all components of the device are combined into one unit. This solution simplifies the operation of the device and reduces cost. Monoblocks according to the installation site are divided into:
- window;
- roof;
- mobile (portable).
Split system- a unit consisting of two separate parts. The external part with the compressor is located outside the building, and the internal part, as the name suggests, is located inside the room. The internal part is mounted on any wall of the apartment.
Multi split system– an extended version of the “household air conditioner”, consists of an outdoor unit and several internal parts (2 – 5 pieces).

To simplify the choice of air conditioner, we will briefly consider the main technical characteristics of this household appliance.

Window air conditioners.

More recently, window air conditioners dominated the market of household appliances, but times are changing, and we have to give way to more technically advanced models. To install such an air conditioner, a technological opening is required - this can be a window opening or a through opening in the outer wall of the house. Most of the device with the compressor is located outdoors, and the small internal part with the control panel is indoors.

The fact that the operating compressor is located “behind the wall” does not reduce the noise level at all. This is the main disadvantage of a window air conditioner. Let's add to it the reduction in room illumination, if installed in a window opening, and the penetration of cold air from outside in winter, and we get the reason why window air conditioners left the consumer market.

Rooftop air conditioners.

This type of air conditioner is installed on the roof of a building and is designed to cool and ventilate large volumes of air. All its component blocks are made in one housing.

Simultaneous cooling and ventilation of air is an undoubted advantage of this design. Let's add here ease of installation, efficiency, low noise level, automatic temperature monitoring system, the ability to not only cool the room, but also heat it using a gas or electric heater, and we get a good device for creating comfort not only in the apartment, but also in industrial and warehouse premises.

Mobile air conditioners.

Video on how to choose a mobile air conditioner

The mobile air conditioner is made in one body, equipped with wheels for ease of movement. One of the advantages of this type of air conditioner is its ease of installation: just take the corrugated air duct hose outside (out the window, for example) and turn on the device. The operating principle of a mobile air conditioner is quite simple: room air is cooled by a compressor, and the product of this activity - hot air - is discharged outside through a 1.5-2 m long hose.

To drain the condensate, there is no need to go out into the external environment; the water is collected in a special container, the filling of which is monitored by a sensor. When the container is full, the device simply turns off based on a signal from the sensor. Many models are equipped with air ionizers, which in itself is useful.

The disadvantages include noisy operation and low power, which does not allow the use of a mobile air conditioner for operation in large rooms. The price of a mobile air conditioner is comparable to the cost of a full-fledged split system - this is a significant factor when choosing.

Wall split systems.

A popular type of air conditioner, consisting of external and internal parts. The unit, which is mounted externally, includes the motor and compressor, and the internal one, with a control panel, is installed in the refrigerated room. A freon line, consisting of copper tubes, connects both blocks to each other.

To create comfortable conditions, split systems provide a useful set of options:

control over the temperature in the room;
filters (carbon, deodorizing and antibacterial);
uniform distribution of cooled air;
reduced power consumption at night;
heating work at low temperatures;

Due to its prevalence and versatility, the wall-mounted air conditioning system is called a “household air conditioner.” It perfectly cools the air in rooms up to 80 sq.m.

Multi-split system.

The operating principle and options of this system are no different from the operation of a “household air conditioner”, but there are differences in installation and rationality of use. One outdoor unit plus any number of indoor units will solve the issue of installing several air conditioners in the direction of simplification. The internal parts of such a unit differ (at will or by the difference in the volume of the premises) in power and are located in different rooms.

By not buying additional external units, you will save a decent amount of money. The disadvantage of this “multi-solution”: if the outdoor unit breaks down, the entire system shuts down.

Functions characteristics of air conditioners

Let's consider the characteristics of a wall-mounted split system, as the most common air conditioner. Most of the parameters considered can be applied to other types of “household cooling appliances”.

Air conditioner power.
Air heating option.
Room ventilation.
Auto mode.
Drying.
Setting the temperature.
On timer.
Night mode.

Power consumption. Do not confuse power consumption and cooling power. The air conditioner, being a refrigeration unit, simply delivers air into the room, therefore, with a cooling power of 2 kW, the device consumes only 600-700 W - this is less than the consumption level of an electric kettle.

Air heating option. Air conditioners that cool the air are called “cold only,” but there is a type of “hot-cold” air conditioner that, in addition to cooling, can heat the air. Such models are more expensive, but they do an excellent job in the off-season, replacing the heater. The principle of heating air, as well as the principle of cooling, is the same, only the blocks work in reverse, taking heat from the air from the street and directing it into the room. Power consumption during heating is 3-4 times less.

Room ventilation. Not all “household” air conditioners have this option. Basically, the cooled air is taken by the device from the same room.

Auto mode. The automatic air conditioner itself heats, ventilates or cools the room, maintaining comfort.

Drying function. By lowering the air temperature by only 1-1.5 degrees, the air conditioner lowers the humidity in the room due to moisture condensation on the heat exchanger.

Setting the temperature. The temperature can be set with an accuracy of 1 degree. This applies to cooling and heating modes.

Scheduled activation. This function allows you to program the air conditioner to turn on and off at any time of the day.

Night mode. By turning on the program, you don’t have to worry about your restful sleep. The automation will switch the fan to lower speeds, which will significantly reduce noise, and smoothly reduce the temperature by a specified number of degrees.

Air conditioner models with a good price-quality balance

Mitsubishi Electric MS-GF20VA/MU-GF20VA.

Minimum set of functions;
Cooling only;
Possibility of installing a low-temperature kit for working in a server room;
Uniform cooling thanks to a wide air flow;
The case is made of high-quality polished plastic.

On/off timer;
Possibility of air flow direction;
Software control with saving settings in memory;
Antioxidant antibacterial filter;

If you are on a limited budget, you should take a closer look at Chinese-made split systems that are not inferior in quality to famous brands: Midea, Arvin, Akira, Tossot, Digital. Of all the choices, I would like to focus on the “budget” model MIDEA MSG-07HRN. Despite its low cost, this split system is equipped with all the necessary options; it cools, ventilates and dries. Two types of blinds, horizontal and vertical, allow you to intelligently distribute the air flow.

An air conditioner is a serious climate-forming device, so do not be fooled by indicators and light bulbs, but choose the device that is most suitable for your room and for you personally. I hope you have understood the functions of household air conditioners, now the only thing left to do is go and buy one. Good luck.

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Today we’ll talk about what technical characteristics an air conditioner can have. A small number of users understand these indicators, and not many know what to look for when doing so.

Probably the most important technical characteristic of an air conditioner is cooling power(or ). The value of this indicator determines how much area of the room the air conditioner can cool in its “normal” mode. And the “normal” mode is the one in which the device’s compressor operates without a constant maximum load. If, for example, for an area of 30 square meters. install the “seven” (designed for 20 sq. m.), then it will be more likely to maintain the desired temperature, but at the same time the compressor will operate in a constant maximum mode, which ultimately can lead to a significant reduction in its service life.

Cooling power is most often expressed in kW. 1 kW of air conditioner cooling capacity can provide 10 sq. m. room area with standard ceiling height (2.5-3 m.)

The next technical characteristic is heating power. The value of this indicator is usually slightly higher than the cooling capacity. Heating power is also measured in kW and reflects the amount of energy that the air conditioner is capable of providing, but only when operating in the “heating” mode.

Split system power consumption

Power consumption- a characteristic that is often confused with previous indicators even by experts in this field. They are confused, most likely, because it is also expressed in kW and, moreover, can also have several indicators (maximum, minimum, nominal). This characteristic shows how much electricity the air conditioner consumes to perform its function (cooling or heating).

Energy efficiency– an indicator that depends on the above characteristics and reflects the efficiency (efficiency) of the split system from an energy point of view. This indicator is expressed by a coefficient, which is defined as the ratio of the produced power (cooling or heating) to the consumed power (for cooling or heating).

Let's say we know that an air conditioner with a cooling capacity of 2.2 kW consumes 0.6 kW of electricity when cooling the room. The energy efficiency coefficient of its cooling operation will be equal to 3.67.

In modern standards, it is customary to distribute the energy efficiency of electrical appliances into classes. Each class corresponds to certain values of this indicator. In our example, the coefficient of 3.67 corresponds to European class “A” (i.e., the most economical devices).

The next important characteristic of the air conditioner is sound pressure value(or noise) of indoor and outdoor units. This characteristic is expressed in dB. The higher the value of this indicator, the noisier the device operates, therefore, the less comfortable it is for the user (and neighbors).

The sound pressure of indoor units has different values at different shaft speeds. For example, for “sevens” at low speed in modern air conditioners, this figure is somewhere in the range of 24-32 dB. For some split systems this figure reaches 19 dB. At high shaft rotation speeds, the noise level of most indoor units is about 36-42 dB.

For “on/off” air conditioners, the noise level of the external unit is approximately 45-55 dB (for “sevens”). In operating mode, such devices have sound pressure at the same value.

The performance of any inverter air conditioner changes during its operation, so the noise level of the external unit also changes. For such air conditioners, only the maximum value of this indicator is usually indicated - about 50 dB.

Another characteristic that the user should pay attention to is permissible operating temperature outside air. It shows at what outside air temperature it is permissible to operate the air conditioner safely (from a technical point of view). It is important to follow the manufacturer's recommendations to ensure high reliability and durability of the device.

Technical characteristics of the air conditioner that are less important for the user

A less important characteristic for the user is air flow. It indicates how much air can “pass” through the indoor unit in a certain amount of time.

There are other additional characteristics that have implications for the design and installation process. They are practically of no interest to the user. These are the following characteristics:

and weight of blocks;
tube diameters;
maximum and minimum length of pipelines;
maximum height difference;
refrigerant type;
cross-section of power and interconnect cables;
and etc.

To summarize: In order to choose an air conditioner, it is necessary to take into account the most important technical characteristics, which are cooling capacity, power consumption, energy efficiency and noise level.

N The most common is the wall-mounted split system. Sometimes wall-mounted air conditioners are also called simply household air conditioners, since they are most often used in apartments. A wall-mounted air conditioner can be installed in any small room - office, apartment, store. Their power (2...7 kW) allows cooling from 15 to 80 m2. The indoor unit of wall-mounted air conditioners is usually installed at the top of the wall, near the window, and the outdoor unit is under the window. This placement makes it possible to reduce the distance between blocks, and therefore the length of interblock communications, which, unless there are special instructions in the passport, is no more than 15 m when the blocks are placed horizontally and no more than 7 m when placed vertically.

When installing split systems, residential premises are ventilated naturally. Since such air conditioners usually operate on recirculation, if necessary, the supply of fresh air to the premises and the removal of exhaust air are carried out by separate supply and exhaust ventilation systems. A caveat should be made here. There are several models of wall-mounted air conditioners on the market today. with fresh air supply first of all this wall-mounted air conditioner Daikin FTXR28E , its price is actually more than $2000. An alternative to it can be, at a price less than $900 this model made in Japan, which undoubtedly speaks about its quality.

Duct air conditioner

TO anal air conditioner is installed behind a suspended or false ceiling, which completely hides the indoor unit. The cooled air is distributed through a system of thermally insulated air ducts, which are also located in the ceiling space. Thanks to this design, a ducted air conditioner can cool several rooms at once. The typical power of these air conditioners is 12...25 kW, which is enough to cool a small office or a 4...5-room apartment. The fundamental difference between a ducted air conditioner and other split systems is the ability to supply fresh air in the volumes necessary for complete ventilation of the premises.

Thus, the use of one duct air conditioner allows you to solve the problems of both ventilation and air conditioning of an entire office, apartment or cottage.

A split system with forced ventilation, equipped with an electronic control system, maintains the desired microclimate parameters at any time of the year. In summer, the air is cooled and the room is maintained at the set temperature. In autumn and spring, the air conditioner switches to “heat pump” mode and effectively heats the air without turning on the heater. If the outside air temperature drops below 0 °C, an additional heater is turned on.

Cassette type air conditioner

D To install a cassette air conditioner, just like for a duct air conditioner, you need a suspended ceiling. However, unlike a ducted air conditioner, it distributes cooled air through the bottom of the unit. The main advantage of a cassette air conditioner is its invisibility, since only the decorative grille is visible. Another advantage is the uniform distribution of air flow in four directions, which allows you to use just one cassette air conditioner to cool a large room (when using wall-mounted split systems, you would have to use 2...3 air conditioners of lower power to achieve a similar effect).

Floor-ceiling air conditioner

E If there is no suspended ceiling in the room, then an alternative to a cassette air conditioner can be a floor-ceiling air conditioner (or simply a ceiling air conditioner). These air conditioners are distinguished by a small distance from the wall (ceiling) - 18...25 cm. They are installed, as the name suggests, either at the bottom of the wall or on the ceiling. This design allows the cooled air to be distributed more evenly throughout the room and avoid direct flow on people.

Column air conditioner

TO Column air conditioning is used where high cooling capacity is required and there are no strict requirements for the design of the room. The internal units of these air conditioners have the same dimensions as a refrigerator, are heavy and are installed on the floor. Column air conditioners create a strong flow of cooled air, which does not allow you to be in close proximity to the air conditioner, so these air conditioners require a relatively large area for their placement.

The air conditioning system can use a “chiller” device with an air-cooled condenser. (A chiller is a refrigeration machine with an intermediate coolant.) In residential premises there are fan coil heat exchangers with fans. The fan coil piping system can be two-pipe (they work only for cooling, but in winter they can switch from a chiller to an individual heating system) and four-pipe (such fan coils work as heating radiators in winter).

Cabinet-mounted independent air conditioners

Autonomous cabinet air conditioners with an air-cooled condenser are designed for year-round air conditioning of premises. Air conditioners operate in different climatic conditions, including the humid tropics, at ambient temperatures up to 45 ° C, maintaining room air temperature in the range of 12...28 ° C and humidifying it.

The air processed in the air conditioner enters either directly into the room or through air ducts into areas maintaining comfortable conditions.

Conveyors

Conveyors provide five functions - cooling, ventilation, cleaning, humidification and air ionization. These devices provide a constant flow of cooled air without the use of environmentally harmful gases and air recirculation. Mobile evaporative coolers/humidifiers cool the air using water evaporation technology.

At an outside temperature in the range from 25 to 40 °C and a relative air humidity of 30... 55%, the devices provide indoor temperatures in the range of 20...29 °C with a relative humidity of 45... 70%.

The principle of operation of the conveyor is based on the use of an air cooler, which has a special filter inside, which is constantly saturated with moisture. The built-in fan, taking in warm air from the room, passes it through a filter that cleans the air of dust, then the air passes through a special wet filter, gives off energy to evaporate moisture and cools. As a result, clean, cooled air enters the room.

Evaporative coolers increase indoor air humidity because they use ordinary water as a coolant, which evaporates as warm outside air passes through a water filter. Therefore, one of the basic principles of the effective functioning of air coolers is that the amount of air supplied into the room through the cooler must be equal to the same amount of air removed from the room through open doors, windows, and exhaust ventilation. Otherwise, the humidity may reach a level of discomfort for people in the room.

Air coolers provide reliable cooling at outdoor relative humidity levels of up to 60%. The efficiency of their operation increases with a decrease in the relative humidity of the outside air and an increase in its temperature.