What is a multi split system: principle of operation + installation and connection rules

Alexey Dedyulin
Checked by a specialist: Alexey Dedyulin
Author: AnnaV56
Last update: February 2020

Agree, air conditioning can make life easier, make it much more comfortable. In the summer, it will provide a cool and pleasant sleep, and in the winter it will help to warm up. But how to make a good choice? After all, the modern market offers thousands of models of HVAC equipment. For example, the trend of recent years is a multi-split system, what is it, how does it differ from similar air conditioning systems?

If you listen to reviews of multi-splits, you can hear diametrically opposing opinions. Someone is delighted, but she clearly did not justify anyone's hopes. Why it happens? As a rule, due to a lack of understanding of the operating principle and technical features of the system as a whole, or due to improper installation and connection.

Let's try to figure out what a multi-split system is, how it works. Consider the advantages and disadvantages of this technique and talk about the intricacies of installing equipment.

What is a multi-split system?

A multi-split system is a special climatic equipment designed for conditioning and maintaining certain climatic parameters of air in rooms for various purposes. Consists of at least three elements.

There is always one outdoor condensing unit, which is installed outdoors, outside and is mounted on the facade of the building. And at least two internal evaporator modules, which, in fact, cool / heat the air.

Multi-split system control
Despite the fact that the operation of all network conditioners depends on one external unit, each of them is autonomous in its settings and adjustment. To control each module, its own remote control is provided, which you can set your own, different from other parameters of the air conditioning mode. It is only important that all devices work either for cooling or for heating. Otherwise, the entire system may malfunction

When installing this air conditioning system, it is necessary to take into account both the totality of the characteristics of all its devices and the technical capabilities of each of them.

External air conditioning unit

The main feature of the external module is its power. The performance of one unit must ensure the normal functioning of all internal devices in one climatic mode.

As a rule, it is difficult to calculate it yourself, since the calculation is made on a differentiated scale. But for an approximate determination of the power rating, you just need to add up the indicators of each indoor unit. The amount received should be equal to the external power.

But the result of this calculation will be relative, because the following values ​​were not included in it:

  • cooling capacity;
  • operating modes;
  • area of ​​premises;
  • climatic features of the region.

There are models of already assembled multi split systems. In them, the performance of the outdoor unit already implies a load of a fixed number of indoor modules.

After the purchase, the system is ready for installation - you do not need to count anything else.

External block multi-split system
The condensing unit is a key part of any split system. It provides heating and cooling air. It consists of a housing containing a compressor, a condenser, a fan, valves, a filter drier, as well as capillary tubes and expansion coils.

The advantage of typesetting systems is the ability to choose different types of air conditioners for any of the rooms.

This may be relevant when the purpose of these premises involves the presence of different volumes and tasks of air conditioning. In this case, the development of an air conditioning system project should be entrusted to professionals.

Indoor units of multi-conditioner

The internal devices of a multi-split system are de facto no different from ordinary ones. The difference is only in their number and the possibility of using several types of modules at once within the same network.

Multi split system
This system makes it possible to use a device that is optimally suited for power, functionality and aesthetic parameters for each room. For example, by installing a cassette module in the sales area, and in the adjacent cabinet, a wall module

Types of air conditioners that can be used in the operation of the system:

The multi system makes it possible to use several types of internal devices without cluttering the facade with condenser boxes.

The principle of operation of multi-split systems

Technically, the multi-split system works and bicomponent split system the same, since each internal device has its own, separately dedicated highwayleading to the outdoor unit.

Heating and cooling is provided due to phase transitions of the refrigerant from the liquid state to the gaseous state and vice versa, due to the difference in pressure and temperature.

When converting freon from liquid to gas, air is cooled in the room, and the reverse process generates heat.

The principle of operation of the split system
The principle of operation of KKB air conditioner is always the same for all split devices of this power level. But, depending on the model, the unit may be distinguished by separate, related characteristics - noise and power levels

The movement of the refrigerant from the outdoor unit to the internal is via two-pipe ducts. This technical feature also explains the main disadvantage of multi-split systems - the impossibility of simultaneous operation of air conditioners in different modes. Only heating or only cooling.

Advantages of the multi-system

The demand for multi-split systems is simply explained.

Their most important advantages:

  1. Aesthetics. There is no need to clutter the facade or walls of the house with dimensional boxes of the external unit, one for each internal device.One or two is enough, capable of providing the necessary rooms of an apartment or a private house with the necessary microclimate indicators.
  2. Each air conditioner is configured remotely by an individual remote control.
  3. The ability to choose air conditioners of various types to work in one system. So you can choose the best device for each room.
  4. Maximum sound insulation. Since the main source of noise - the condensing unit is mounted outside, and it is one - the noise of the working air conditioners, even with the windows open, is virtually inaudible.

Moreover, the cost of such a multi-system is not much more expensive than an ordinary one.

Multi-split system in the house
Most users call the main advantage of the system - a wide range of operating temperatures. This allows you to configure the equipment to work in the desired temperature range.

The combination of these advantages is often a very strong argument in favor of choosing a multi-split system. Even despite its obvious and not-so-weaknesses.

Disadvantages of the climate system

A multi split system is not ideal. She has her own shortcomings that must be taken into account.

This is first of all:

  • complicated installation. From each air conditioner, you need to draw your own channel to the external unit;
  • higher price for installation of equipment;
  • the impossibility of simultaneous operation of the system air conditioners in different modes. For example, in one room to warm the air, and in another to cool.

There are disadvantages in any device. But, for example, choosing a compressor injector type and setting it an order of magnitude lower than the internal modules can significantly reduce the amount of electricity consumed during the operation of the system without losing its performance.

Air conditioning installation

Regardless of which building (wooden, brick) is produced system installation, it is better to order these works to specialists.

Mounting a split system
Often the installation of the entire multi-system is not only a responsible matter, but also quite dangerous. This is especially true for the installation of KKB in the apartments of the upper floors of high-rise buildings

The efficiency of the entire system will depend on how much the technology for laying each channel and taking into account the features of the selected types of internal modules is respected.

By default, the entire workflow can be divided into stages:

  1. Designing - the location of all the main components and components of the system, the location of the laying of the main and electrical wiring.
  2. Markup.
  3. Installation of electrical wiring.
  4. Mounting / fixing the box of the outdoor unit on the wall.
  5. Laying of the highway.
  6. Installation of internal system modules.
  7. Filling the system with freon.

After connecting a multi-split system, testing of all its performance indicators is mandatory.

Hardware Installation Process

When the project is ready, the process of installing multisystem equipment begins, as well as laying and connecting communications.

First of all, an external unit is attached to the external wall on the brackets at a distance of no more than 20 meters from the internal modules. This is the average value, for each block of the system from different manufacturers, its own maximum permissible length of the distance from the compressor-condenser block is provided.

Having fixed the block on the wall, it marks the place where communications will be drawn from it - drainage, interconnect and power cables, two copper tubes from each indoor module in isolation.

The next step will be marking the direction of the output location under a slight slope. When drainage is provided outside, the average slope is calculated in the range of 5 mm per meter of the entire length of the route.

Connecting the drainage channel to the sewer
A hole is drilled in the outer wall with a diameter of at least 50 mm (the more indoor units, the wider). When planning the removal of drainage into the premises, into the sewage system, the hole is also made with a slight slope down to the siphon.When connecting the drain to the sewer riser, it is necessary to use siphons with a water seal. This is necessary to exclude the very possibility of sewage "odors" entering the air conditioning system, and, consequently, the spread of unnecessary odors around the house

On the marking lines, gating is carried out under the laying of the highway or a decorative box is applied along the entire length to the junction.

When laying a drainage system, it is necessary to adhere to the norms:

  • the slope of the horizontal sections should be 3%;
  • turns and bends of a hose should not exceed 45º.

Cable routing from KKB should go directly to the distribution panel. This is the most optimal option for energy distribution - it gives a certain autonomy to the system, making it independent of the work and energy consumption capacity of other household appliances.

In addition, from the point of view of aesthetics, it allows you not to clutter up the walls with cables, sockets, cords and plugs. And from the point of view of convenience - external units in each room will be switched on directly from the remote control.

Having installed the blocks of internal modules, the commissioning work itself begins. All communications are connected to the equipment modules, flare nuts are tightened tightly, with effort to achieve the required level of tightness of the connection.

When all elements of the system are connected, and it is already closed, air and water are pumped out from the freon line of the network.

The last actions of the installers is to open the external ports of the equipment, start the refrigerant and test the air conditioning system - checking the operation in all modes at the maximum capacity of the equipment.

Common installation errors

It happens that, after reading the installation instructions from the manufacturer, the owners of multi-split systems that have not yet been mounted trust this work to amateurs.

In 90% of cases, this solution leads to installation errors:

  1. Installing an external air conditioning unit in one plane with internal devices - reduces the performance of the entire system, increases energy consumption.
  2. Mounting the compressor on the wall of a glazed balcony is a lack of air for heat transfer.
  3. The bend of the pipes of the line along which the refrigerant circulates - a decrease in throughput, an increase in the load on the compressor.
  4. Installation of internal system modules above heating radiators or other heating devices.
  5. Poor rolling compound quality - the system will lose freon very quickly.

Not all installation errors are listed, because it happens that the system is not refilled with refrigerant, or the slope is incorrectly calculated, etc.

Therefore, savings on installation can lead to a quick breakdown of the system air conditioners.

Split system installation
Specialists of a service center or a reliable company whose profile is installation and maintenance of the air conditioner can guarantee that KKB is installed correctly, but they will also try to make it look beautiful and not cause complaints from the neighbors from below (if the air conditioner is installed in a multi-storey building). After all, not everyone will like condensation dripping from above

In order for the installation to be reliable and the system to work properly, it is necessary to use specialized equipment during installation and have professional knowledge and skills.

This will ensure the duration of operation and the effectiveness of air conditioning in accordance with the parameters declared by the manufacturer. In addition, service centers give a guarantee on the quality of their work. Therefore, if something goes wrong - they will be obliged to fix the installation errors at their own expense.

The problems listed above are the first signs of a device malfunction. Specialists of air conditioning system maintenance services recommend immediately contacting relevant organizations for diagnostics and repair if problems are found.

Timely identified problem can be solved by a small repair or replacement of a spare part. Ignoring can lead to a quick exhaustion of the resource and damage to the entire system.

Conclusions and useful video on the topic

The principle of operation of a multi-split system is presented in the following video:

Comparison of split and multi-split systems can be seen in the following video:

Choosing an air conditioning system, especially in a residential area, is a responsible matter. After all, any device has its own characteristics and technical capabilities.

The main thing to remember before making a responsible decision is the need to part with pink glasses and boldly look at the advantages and disadvantages of the system you like. Indeed, depending on the needs of the user, they can change places and from the minus become a plus and vice versa.

If you have experience using a multi-split system, please share it with our users.

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