Climate for every taste

It can cool, heat, dehumidify and purify the air. His «intellectual abilities» are quite worthy of the 21st century and continue to develop rapidly. And the air flow it creates is remarkably similar to natural wind. In general, our today’s «guest» is air conditioning.

Air conditioner architectonics

One day, a hundred years ago, a certain owner of a New York printing house ordered the inventor Willis Carrier a machine to reduce the humidity in the room. Note that the main goal was to improve the quality of printing, and not at all to create comfortable conditions for workers. This is how the first air conditioner came into being. And since the 40s of the twentieth century, with the advent of freon, this wonderful device settled in residential buildings and offices. Suffice it to say that today in the United States much more money and energy is spent on cooling rooms than in Russia on heating.

AIRWELL.
Daikin. When the flow of cold air from the indoor unit of the split system is directed along the wall, there is no uncomfortable draft.However, to associate the word «air conditioner» only with air cooling is not quite right. Air conditioning means creating comfortable conditions for a person. And this sometimes requires not cooling, but heating the air, not to mention its purification from harmful impurities and maintaining the optimal level of humidity.

Currently, there are several air conditioning schemes that use different types of appliances. For example, cottages are gradually beginning to use ducted, separated from supply ventilation, roof and central air conditioners. These are units with a power of more than 10 kW, designed for buildings with a large number of rooms. The presence of such devices in the house is laid already at the design stage. In apartments, household monoblocks and split systems are most common. Basically, we will talk about them.

Monoblock air conditioner — the most famous among their own kind, and besides, the closest relative of a household refrigerator. It consists of a single unit of condenser and evaporator. Can be windowed or mobile.

Well-known to many of us, “windows” are mounted both in window and doorways (models LWH0560ACG — LG ELECTRONICS, RA-3147CL — HITACHI, AWO5EOLE — SAMSUNG). Part of the room air taken in (up to 10%) is released into the street, thereby providing forced exhaust ventilation. However, they reduce the light area of ​​the window and, accordingly, the illumination of the room, require alteration of the opening, and the rattling of glass is not a very pleasant background for life. In addition, these devices are completely incompatible with the fashionable double-glazed windows.

SHARP.
Daikin. A high-quality indoor unit of a split system must combine the seemingly incompatible: to be powerful, silent and inconspicuous.A mobile air conditioner takes air from the room and divides it into two streams: hot and cold. Hot through a flexible hose is thrown out of the building (for example, through a window), and cold remains in the room. The unit can be rolled on the floor, as far as the flexible hose allows, transferred to another part of the house, or even taken to the dacha. Somewhat complicates the use of the device, the need to periodically empty the container with condensate, which is formed when the air is cooled. If you miss the moment, a mobile air conditioner can “make a puddle” on the floor.

Monoblock systems are cheap, easy to install and reliable in operation. True, they are not as elegant and silent as split-system air conditioners.

split system (or split air conditioner) got its name from the English word split — to split. In this design, the condenser and evaporator are separated into different blocks: external and internal. An external one with a condenser, a fan and a noisy compressor is hung outside on the wall of a building or mounted on a balcony, while an internal one with an evaporator, a filter and its own fan (usually low-noise, tangential type) can be installed anywhere in the room: under the ceiling, behind a false ceiling, on the wall , on the floor. The blocks are interconnected by pipelines for supplying freon. It transfers heat from the indoor unit to the outdoor unit, so that the temperature of the heat exchanger of the outdoor unit is higher than the outdoor unit, and the indoor unit is lower than the room temperature. The fan of the indoor unit blows over the evaporator radiator, which cools the air that is then supplied to the room. Another fan, mounted in the outdoor unit, serves to cool the condenser, but fresh air from the street is not directed into the room.

This type of air conditioner cools only the air that is in the room. This constructive solution has one significant drawback: since fresh air does not enter the room, the concentration of harmful substances in it increases. The room has to be ventilated from time to time. On the other hand, this mode of operation is the most economical (the air conditioner does not cool the street).

The «miracle» of air cooling is based on two properties of the liquid: to absorb heat when boiling and to release — when steam condenses. The main elements of residential air conditioners are: evaporator, condenser, compressor and liquid refrigerant flow controller. All of them are connected by pipelines with a refrigerant (usually freon) in a closed circuit. Freon boils in the evaporator. This uses heat from the room air flow directed by the fan onto the finned surface of the evaporator. Thus the air is cooled. If freon vapors are compressed and sent to the condenser assembly, they will begin to turn into a liquid, giving up their heat to the walls of the condenser and through them to the surrounding air, even if it is hot. For example, when compressed to 23 atm, freon condenses at a temperature of about 60C. This means that in order to cool the condenser, it is possible to direct the flow of not only room air, but even street air to it in the hottest summer. The compressor ensures the circulation of freon in the circuit and the desired high pressure in the condenser.

So, the heat of the room air is transferred to the freon vapor in the evaporator and is taken away by the air blowing around the condenser and thrown out into the street. If you want to air-condition the entire apartment, there is no need to purchase the number of split systems according to the number of rooms, you can use one multi-split system. In this design, one outdoor unit is able to serve from 2 to 8 indoor (Super-Multi series — DaikinLM — LG ELECTRONICS).

Since 1961, when the Japanese company TOSHIBA developed the first split system in history, the popularity of this device has been steadily growing in all countries, with the exception of the main consumer of air conditioners — the United States. The Americans do not allow products of this kind from Japan and Southeast Asia into their market. They themselves produce and use approximately equally «windows» and central air conditioners. Analysts from the economy see the reason for such rejection of split systems in the peculiarities of the American mentality and, in addition, in the natural conservatism of a typical «state» homeowner. But the Europeans, on the contrary, prefer split systems, and window monoblocks make up only 15% of the air conditioners they buy. Residents of Russia use approximately 10% of central air conditioners, 20% of window monoblocks and 70% of split systems.

The number of manufacturers and the variety of models of air conditioners on the Russian market can confuse anyone who is going to purchase a split system. In Moscow, you can find air conditioners from the Russian company «ELEMASH», as well as from Japanese companies TOSHIBA, HITACHI, SANYO, DaikinSHARP, FUJITSU—GENERAL, South Korean SAMSUNG, LG ELECTRONICS, DAEWOO-CARRIER, European AIRWELL (France), DeLONGHI (Italy) and American firms CARRIER, GENERAL ELECTRIC, etc. All this still prestigious household appliances are being continuously improved. In the pivot table, we have indicated only a part of its suppliers and some parameters. The most curious technical innovations in this area will be explained separately.

Heat pump

Working in its normal mode, the air conditioner takes heat from the room and sends it out the window, cooling the room and heating the street. But some designs allow you to run the refrigerant in the opposite direction, changing the functions of the evaporator and condenser to the opposite ones (models CP10-2000 — DeLONGI, ASY7RSC / AOY7RSC — FUJITSU and many others). In this case, the air conditioner starts to cool the street and heat the room. This is the heat pump mode. From the point of view of electricity consumption, a heat pump is more than twice as economical as a conventional heater, since it does not create heat itself, but only “pumps” it from the street into the room. Unfortunately, if it’s -20 outside the windowC, it becomes problematic to take heat from the street. Without dwelling in detail on the peculiarities of the operation of a heat pump in the conditions of the Russian winter, let’s say that it makes sense to use it as a fan heater in the off-season — in spring and autumn (-15 … +15C) until the central heating is turned on. At lower temperatures outside the window, we recommend using traditional heating methods.

Air conditioners with a heat pump function are 5-10% more expensive than ordinary ones.

Wall mounted split systems with heat pump

Note. Prices for the same models differ from supplier to supplier and were determined randomly in autumn 2000.

inverter air conditioner

Daikin.
Daikin. The outdoor unit of the split system is best located in an easily accessible place to simplify maintenance. In this case, the block must be protected from mechanical damage.An ordinary air conditioner resembles a refrigerator: either it works «at its fullest», or it rests — it all depends on the temperature in the room and the parameters set on the control panel. An inverter air conditioner (more precisely, having an inverter power supply), unlike a conventional one, is able to smoothly adjust the compressor speed and thereby smoothly change the cooling (or, conversely, heating) speed of the air (models RAS-25CNH1 — HITACHI, RX25HV1NB — Daikin and etc.). The «inverter» reaches the required parameters and maintains them at minimum speed, coordinating its performance with the heat dissipation in the room. These air conditioners are as much as 30% more economical to operate and less noisy, reducing the number of on / off cycles increases the life of the compressor. In addition, inverter air conditioners are 10-15% more expensive than conventional ones.

Features of the split system in winter

There are situations when cooling a room in winter is just as necessary as in summer. This happens if during the heating season the central heating supplies an unreasonably large amount of heat. Another option is if the heat dissipation in the room is too high for any reason (due to the large number of operating equipment). It is impossible or undesirable to reduce the temperature by opening the window due to an unacceptable decrease in humidity, etc.

When choosing an air conditioner that is supposed to be used in winter, one should not forget that the birthplace of the split system is the Land of the Rising Sun. Most likely, the developers of remote units knew about the Russian winter only by hearsay. The paradox is that at temperatures below -15With the cooling capacity of the system drops sharply — and this despite the frost outside the window. When the ambient temperature drops, the pressure decreases, at which freon vapors begin to condense in the outdoor unit, the evaporator fills worse, and as a result, the production of cold is reduced. In addition, in the cold winter, the split system begins to malfunction even in the heat pump mode. When the air temperature in the room is low, the vaporization in the evaporator deteriorates, the liquid does not completely evaporate, and its drops can enter the compressor, leading to water hammer and breakage of the compressor valves.

Especially for the operation of air conditioners in winter conditions (up to -20C) the developers have provided for automatic adjustment of the fan speed of the outdoor unit, heating of the oil in the crankcase and the drainage tube for draining condensate, as well as periodic defrosting of the outdoor unit in the heat pump mode. These additions exist in the devices of the domestic plant «ELEMASH», the Italian concern DeLONGHI, in low-temperature split systems of Japanese companies Daikin and TOSHIBA (model RAV-163/263KH-PE).

Filtration, dehumidification and air purification

It should be emphasized once again that the fan of the outdoor unit of the split system is intended only for cooling the compressor and refrigerant, and not at all for supplying fresh air to the room. Thus, we are talking about filtering and cleaning room air.

Usually, three filters are installed in the air conditioner: a coarse air filter, an electrostatic filter that traps fine dust, and a carbon filter that absorbs and accumulates molecular impurities. SAMSUNG additionally uses a special antibacterial coating that prevents the growth of all kinds of microorganisms inside the air conditioner. Firms Daikin and LG ELECTRONICS use the most advanced photocatalytic air purification method. So, in the LS-K1862HL model from LG ELECTRONICS ($ 1980), a plasma ionizer and a photocatalytic filter work. The first, by charging particles of pollution, helps to capture them using an electric field, and the second decomposes impurities (for example, tobacco smoke) to substances harmless to humans.

Split system air conditioners can be divided into five types: wall-mounted, floor-ceiling, column type, cassette type and multi-zone with variable refrigerant flow.
wall (power from 1.5 to 5 kW in the cold) we are the most famous and more often than other types are used in city apartments.

Floor and ceiling air conditioners are becoming more powerful (from 4 to 9 kW). Their indoor unit is designed in such a way that it allows you to direct a strong jet of cold air along the wall or ceiling without causing an uncomfortable feeling of draft. Approximately the same do floor columnar air conditioners (power from 5 to 15 kW) installed in large halls and halls without false ceilings. The indoor unit is conveniently hidden behind the false ceiling of large rooms cassette conditioner. In this case, after preparation, the air is distributed in four directions through adjustable shutters. For buildings where it is necessary to cool many rooms with different thermal conditions, more suitable multizone systems with variable refrigerant flow. In them, up to 16 internal units of different power can be connected to one external unit, operating independently of each other.It must be borne in mind that dense filters are required for air purification, the use of which reduces the cooling performance and worsens the noise characteristics of air conditioners. Some manufacturers, in pursuit of reducing the cost of devices, abandoned the cleaning function and in their brochures emphasize the low cost, efficiency and «super-silence» of their products. Others are trying to find a compromise between the efficiency of cleaning and the noise characteristics of split systems. But still, more often the “compromise” is shifted in favor of cooling and noiselessness, so a household air conditioner is not able to replace a full-fledged air cleaner. In addition, the air purification system must be monitored. The electrostatic filter requires periodic washing, and the carbon and some photocatalytic modifications require regular replacement. If the filters are not replaced in time, their air resistance becomes higher, which reduces the service life of the air conditioner. In addition, dust and dirt serve as food for bacteria and fungi.

Among the many advantages of split systems, I would like to note one more thing: the ability to drain the room. This is done automatically when operating in cooling mode. Typically, an air conditioner condenses 1-2 liters of water per hour. Condensate through the drain pipe can be discharged into the sewer or outside.

Installation, warranty and operation

After choosing the type of split system that suits you (with a heat pump, inverter power supply, air cleaning system or for operation in winter), you should determine the cooling capacity. It is unwise to buy a system that is too powerful. Also, do not force a weak air conditioner to tear around the clock. By eye, the power is determined by the area of ​​u200bu200bthe room (100 W for cold per 1 sq. M). A more accurate calculation includes an assessment of the area of ​​​​glazing, the orientation of the building to the cardinal points, the number of heat-generating devices, people in the room, etc.

The location of the outdoor unit is also important. This part of the split system should be available for routine inspection and repair, so it is best to keep the outdoor unit on the balcony. It must be periodically cleaned, for example, from dust, soot and poplar fluff, the last of which, according to repairmen, is responsible for a third of system failures. Firms, of course, are trying to improve the reliability of the units and provide for various measures to protect them from the aggressive effects of the external environment. So, in the already mentioned model LS-K1862HL, the heat exchanger is covered with two protective layers — anti-corrosion Gold Fin and a special water-repellent one. However, they will not save you from falling icicles. In addition, it is better to remove the external block out of sight: sticking out on the facade like a wart, it does not decorate the already dull landscape of the native city at times.

Daikin.
Daikin. The indoor unit of cassette air conditioners is hidden behind a suspended ceiling, above which air ducts can be laid to supply fresh outdoor (up to 10%) or cold air to an adjacent roomSo, suppose you decide to entrust the installation of a split system to some reputable company. It may turn out that the already considerable price indicated in the price list does not include consumables (brackets for mounting the outdoor unit, refrigerant route, drainage, etc.) and installation costs. Please note: a guarantee is given to the buyer not by the manufacturer, but by the company that installs the air conditioner, and the installation cost often includes the price of warranty repairs. Thus, together with the installation, the air conditioner will cost about 35% more. But if you decide to save money, keep in mind: on the building materials market you can find an air conditioner for half the price, and to install a split system, use the services of a team of «flying covens». In this case, you need to be prepared for the fact that your air conditioner:

1) is assembled at a semi-underground factory somewhere in China or Malaysia and, most likely, is not adapted to Russian conditions. In this case, the pressure blocking may work already at a temperature of +10…+15C, and then the air conditioner will “fall asleep” deeply until next summer;

2) represents a rejection from the company’s factory;

3) nothing more than a worn-out and second-hand tinted one from somewhere in the United Arab Emirates.

In any case, no one guarantees anything, except perhaps that this technique is unlikely to last long.

For the competent installation of a split system, the installer, in addition to experience, requires expensive professional equipment. For example, if the refrigerant pipe was sawn off with a hacksaw, then there is a high probability that metal dust will enter the circuit, which will eventually ruin the compressor. But then it will hardly be possible to find “flying covens”.

Unlike its closest relative, the refrigerator, which lives “in human conditions,” the split system experiences all the features of our continental climate. The presence of threaded connections or microcracks in the refrigerant route can cause freon leakage or moisture ingress into the system. Therefore, to prevent irreversible failures of the air conditioner, it is necessary to subject all its components to a thorough inspection at least once a year. Specialists from the service department will make a detailed diagnosis and the necessary prevention. And then, in response to the warmth and care, the air conditioner will answer you with the desired coolness and comfort.

• Source: Ideas for Your Home Magazine#39