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Updated on June 27, 2022 1:19 am
All countries
Updated on June 27, 2022 1:19 am
All countries
Updated on June 27, 2022 1:19 am


All countries
Updated on June 27, 2022 1:19 am
All countries
Updated on June 27, 2022 1:19 am
All countries
Updated on June 27, 2022 1:19 am
All countries
Updated on June 27, 2022 1:19 am

How to install an air conditioner (split system)

It is not enough to buy an air conditioner. Still need to install it! They say that installing a split system is a troublesome, time-consuming task. Is it really? In this article, we figure out where it is better to hang the air conditioner and how to install it yourself in general – or maybe it’s better to completely give these worries to the masters. Spoiler: delegate is definitely better.

Features of choosing an installation site
So, you have read a bunch of articles on choosing an air conditioner , decided on a model and purchased a split system that is suitable for your room. How to install it? There are exactly two options: pay other people or try to do it yourself (but it’s better to trust the professionals. Let’s see what you need to pay attention to first.

First, let’s decide on the installation location of both the external and internal units. The comfort and safety of using the air conditioner, as well as the efficiency of its work, will depend on this.


Space for indoor unit
The indoor unit must be positioned so that it is NOT directly in front of the places where people are most often: sleeping places, sofas, dining tables, workplace. The cold air from the indoor unit of the air conditioner comes out straight (the direction can be slightly adjusted horizontally or vertically with the air conditioner’s louvers) and should not be allowed to hit you. Otherwise, as you may have guessed – hello, constant colds.

In the bedroom, it is desirable to install the indoor unit at the maximum distance from the bed, but if the room is small, then the best option is above the headboard, then the air flow will only fall on the legs of sleeping people, who are usually covered with a blanket.

Modern outdoor units of split systems have the following typical options for the output of refrigerant (freon) pipes and drainage. The tubes of the indoor unit are usually located on the right side (when viewed from the front) and can be gently bent to the desired direction. Some models of air conditioners have the ability to move the drain tube from the right side to the left.


The installation height of the indoor unit should be at least 1.8 m from the floor level, and the distance from the walls and ceiling should be at least 50 mm. Moreover, the more powerful the split system, the greater the distance from the walls is required (for example, for air conditioners with BTU18000, the recommended height is 2.3 m and the distance from the walls is at least 15 cm).


It is not recommended to place the outdoor unit in the following places:

where the airflow is blocked, such as by furniture or curtains
near heat sources: above radiators, heaters, near gas equipment, open flames
across from the door
under direct sunlight
An important point is the presence of an electrical outlet or cable near the installation site of the indoor unit. In most modern models, it is the indoor unit that is connected to the mains power supply, and the external unit also receives power from it. It is highly desirable that the split system be connected to a separate electric machine of the appropriate power in the electrical panel: up to 2kW – C16A, from 2kW and above – C25A.

It is necessary to pay attention to the removal of condensate, which is formed when the air is cooled on the evaporator of the indoor unit. A big plus would be the option when the condensate is discharged into the sewer or downpipe, and does not drip onto the window sills of the neighbors from below, splashing their windows, as well as on the heads of people passing below. For drainage to work, it is necessary to ensure the gravity flow of condensate due to the angle of inclination of the drainage tube. If, for some reason, this is impossible to ensure and the drain pipe needs to be laid horizontally or, for example, along the ceiling, then you will have to additionally install a drainage pump (condensate pump) that provides forced pumping out of the accumulated liquid.

Wall split system DEXP AC-CH12INV
9000 BTU, 25 m²
12000 BTU, 35 m²
35 999 *
Such pumps are divided into four types: separate (accumulative), bulk, built-in and peristaltic. Each type has its own characteristics of installation and use, as well as the capacity (liters per hour) and the height to which condensate can be pumped.


Modern pumps have a fairly low noise level, but this is an additional and expensive element that complicates the design of the system, so you need to think about how the drainage will go already in the process of choosing the installation location of the indoor unit.

In general, recommendations for installing the indoor unit can be reduced to the following points:

good air circulation
distance from other appliances and heat sources
doesn’t blow on people
convenient drainage
noise protection
solid and durable mounting surface
service access
Space for outdoor unit
When installing an outdoor unit, certain rules must also be observed. Do not install in places without the possibility of exhausting warm air from the front and supplying it from the back and side of the unit. Good circulation and ventilation is required.

Due to the fact that the outdoor unit is quite heavy, the brackets on which it is installed, the fasteners and the base must be strong and withstand the weight of the unit. It is not recommended to install it on metal fences due to the possible strong vibration of the structure.

It is advisable to install the unit in places where it is protected from constant exposure to sunlight and precipitation. Above the unit, you can install an additional canopy-visor from precipitation, and in places with strong winds – a protective screen.

You do not need to place it in the place where there is a working or sleeping place right behind the wall, since the external unit, especially powerful and not equipped with an inverter, can make a noticeable noise even through the wall.

Place for mortgages
If you are renovating an apartment and planning to install an air conditioner in the future, then it is best at this stage to think over the location of all the elements and make mortgages, that is, lay a route in advance connecting the indoor and outdoor units. For these purposes, using a special tool (for example, for concrete or brick – a wall chaser and a perforator), long rectangular channels of at least 50×50 mm are made in the wall material, into which copper pipes are laid in thermal insulation for the refrigerant, one or two electric cables (depending on the model split systems) and a drainage tube. Immediately after laying in the strobe, the ends of the pipes must be carefully muffled so that debris or construction dust does not get inside. You also need to make sure that the soft copper pipes do not get damaged during the repair process.


It is better to lay the route inside the room, and only the short ends of pipes and cables should be led outside – near the location of the outdoor unit.

If the air conditioner is installed in a room where repairs are not planned in the near future, then the option remains with an external box, along which the route runs to the wall.


In this case, it is also highly desirable to run a route along the wall to the outdoor unit in a box. Moreover, this is advisable not only from an aesthetic point of view, in order to avoid the appearance of a building similar to the left photo below, but also from a practical point of view – an unprotected route from the outside will be subject to precipitation, destruction of thermal insulation and, as a result, a reduction in the service life of the system, deterioration in performance and increased consumption energy.


Naturally, the longer the track, the more difficult, longer and more expensive its installation. It should be noted that for each diameter of the pipes through which the refrigerant flows, the permissible maximum length of the route and the height difference between the indoor and outdoor units are determined, when the split system can be used without additional refrigerant charging. In case it is required to lay a longer route (for example, over 15m), it is necessary to add a strictly defined amount of grams of refrigerant for each additional meter of the route through the low pressure valve of the outdoor unit. All this is prescribed in the instructions for the split system. If the outdoor unit is placed higher than the indoor unit and the length of the route exceeds 10 m, then the formation of an oil catcher (bend in the route) for the oil contained in the refrigerant is required.

Wall-mounted split system DEXP AC-CH18ONF
7000 BTU, 20 m²
9000 BTU, 25 m²
12000 BTU, 35 m²
18000 BTU, 50 m²
42 999 *
Typical places for installing blocks and laying the route
The installation of an air conditioner is individual for each room and is determined by the arrangement of furniture, windows and doors, heating appliances, ease of use, etc. But there are a number of typical options:


Installation Tool
To install a split system, you need a fairly specific tool, so it might be worth contacting the masters who have already installed more than a dozen air conditioners and are equipped with everything you need.


The basic installer kit includes:

Refrigerant pipe flare tool
Adjustable wrenches (at least two)
crosshead screwdriver
Allen key (4 mm)
pipe cutter
Pipe edge deburring tool
Cable cutters for cutting wire and stripping insulation
pipe bender
Insulating tape
Sealing tape
Corrugation for electric cable

It is desirable that torque wrenches be used to tighten the conical nuts connecting the pipes of the route with the pipes of the indoor and outdoor units. However, as practice shows, such a tool is rarely found in installer sets; in most cases, open-end or adjustable wrenches are used.

Rolling set:


It is also highly desirable that a vacuum pump (vacuum gauge) and a special pressure gauge with a set of hoses for tightness control be available.

In addition to the tool itself, which may be required to perform the work, an equally important element is a variety of fasteners and other consumables that are in demand during installation.


Moreover, the electric tool used in the installation of split systems in houses made of different materials is different. For example, to pass through walls in concrete and brick walls, a powerful puncher is required (the phone in the photo below is for size comparison) …


… which is used with no less serious drills (from 45 mm in diameter).



In addition to drills, special spear-shaped and spade-shaped chisels are used for the perforator, which will help both expand the hole and make a mortgage in the wall.


For holes in the walls of wooden houses, other drills are needed – feather and crowns, a chisel is also useful. Moreover, in order not to carry an additional drill with you, a hammer drill in the drilling mode with an adapter in the form of a chuck with an SDS shank can work as it.


A necessary element for installation are bays of copper pipes of different diameters to form a sealed refrigerant circuit between the units of the split system. There are two versions of such pipes: annealed (more ductile and flexible, but less durable) and non-annealed (more difficult to bend, but more durable). The most commonly used pipes are the following typical diameters (in inches): 3/4, 1/4, 1/2, 3/8, 5/8. Information about which pipe is suitable for your split system can always be found in the instructions for it. Quality copper tubes should have a wall thickness of at least 0.8mm.

Looking into the car of the installation team, you can always see the following picture: pipes, corrugation, insulation, cable, etc.


A flexible drain pipe (preferably reinforced) is also required to allow condensate to drain from the indoor unit.


The diameter of the drain pipe can be selected based on the following table (20 mm is suitable for domestic air conditioners):


If an installation option is planned, when the route exceeds the permissible length without refueling the system with refrigerant, it is required to ensure the availability of freon cylinders that are suitable for the system being installed. At the moment, the most popular type is: R410A refrigerant and more modern R32. The required type is always indicated in the instructions for the split system.


Of course, the list would not be complete without mentioning the ladder, which is a mandatory attribute of almost any installation.


Installation steps
Having chosen the location of the indoor and outdoor units, determining the passage and method of laying the route as part of the refrigerant pipes, drainage and cable, as well as collecting the necessary set of tools, you can begin the work itself. The installation of a conventional split system can be broken down into the following steps:

marking the places of fastening of the indoor unit and brackets of the outdoor unit
making a hole through the wall
pipe installation, flaring
laying track on the wall
route through a hole
indoor unit installation
outdoor unit installation
connection of the route to the indoor unit (pipes and cable)
connection of the route to the external unit (pipes and cable)
evacuation and leak test/pressurization
opening valves and checking operation
The sequence of some steps, such as installing the indoor and outdoor units or the connection sequence, can be changed depending on the specific situation and installation location – this is determined by the master installer.

Consider all the installation steps. It is important to note that before performing work, it is required to free the desired area of ​​\u200b\u200bthe room from furniture and other objects that interfere with installation, for example, curtains.

For the installation of a split system, at least two people are required, one person simply cannot perform some of the installation steps on his own.

The sequence of marking the internal or external blocks, in principle, does not matter, the main thing is to think in advance where the route will pass and where the blocks themselves will be located on the walls in compliance with the conditions described above. If the route is already laid in the wall, then you will have to start in the markup from the location of its exits.

Below are photos of installing a split system in a wooden house made of timber. Installation in rooms with walls made of other materials, in general, is no different, except for the tool that is required to make a hole in the wall and lay the pipe.

Layout of the indoor unit
Usually, the more powerful the split system, the larger the indoor unit. This should also be taken into account when planning placement and layout.


The indoor unit comes with a removable installation plate, which is rigidly fixed to the wall and on which the device is later fixed.

After measuring the dimensions of the indoor unit and retreating the required distances from the walls, floor and ceiling, using the levels to maintain the horizontal, we fix the installation plate.


Some manufacturers, in the installation instructions of their systems, provide a detailed diagram of the dimensions of the plate and a description of its installation to facilitate the marking. An example of such an instruction.


Outer block layout
Following the recommendations for choosing the location of the outdoor unit, we measure its parameters and mark it on the outer wall. On the marked lower part of the block, we mark the brackets on which the outdoor unit will be fixed. If you plan to install vibration dampers that reduce the transmission noise of the outdoor unit to the wall, the brackets must be lowered to the height of these vibration dampers. The brackets are leveled so that the plane passing through them is strictly horizontal. When marking, we use a bubble or electronic level.


Brackets can be both prefabricated (consisting of several parts that need to be connected together with fasteners) and welded. There is no particular difference which option to use, the main thing is to comply with the load requirement so that the brackets are guaranteed to securely hold the external unit.


In addition, it is important to use reinforced metal fasteners. For example, for concrete walls – powerful anchors, and for wood – screws with a hex head.

Bracket Ballu NS-1037368
999 *
1 150 *
Temperature controller Ballu BMT-2
1550 *
Screen Ballu Split 900
2899 *
Making a hole in the wall
This stage can be carried out both before marking the location of the external block, and after. The second option is more convenient when the units are located across the wall opposite each other, and there is enough space for installing the outdoor unit on the wall. In this case, it will be possible to place the brackets of the external unit as close as possible to the hole and hide it behind the device, as well as the outer part of the route.


When choosing a place to drill a hole, we evaluate the following points:

The presence of communications in the wall (to exclude any possibility of their damage)
The maximum possible concealment of the opening from the inside and outside
Proximity to the junction of the walls – it is very inconvenient to drill a hole in the corner. You also need to avoid getting a hole at the junction of concrete slabs or logs in a wooden house.
The hole is made with a suitable tool at an angle so that its outer edge is approximately 5-7 mm lower than the inner one. The recommended diameter is 70-80mm. In the hole made, it is recommended to install a piece of PVC pipe of the appropriate diameter with a bushing to avoid damage to the route when it is passed through the wall.


When installing in a wooden house, you can do without this tube, which allows you to make a hole of a smaller diameter of 45-50 mm.


Route installation
If the route is already built into the wall, then all the manipulations will have to be performed by fixing the indoor unit with the upper part on the already fixed wall plate and tilting the lower part forward. It looks something like the photo below. In this case, you have to work in a fairly narrow space.


To fix the block in this position, they make an emphasis from all available means. However, some manufacturers have taken care of the installers and add a reclining foot to the design, which can be tilted at an angle of 90 ° to the case, it will rest against the wall and hold the case at an angle. Convenient for both installation and maintenance. In the photo below, the focus is orange.


It is much more convenient to mount the route on the removed block, and then carefully push it into the hole. The route consists of two copper pipes of different diameters, a power cable (one or two, depending on the model of the split system) and a drainage pipe.

An important point is that when mounting under the front panel of the indoor unit, be sure to put something soft, such as packing foam. This is necessary to exclude the possibility of damage to the panel and shutters of the unit.


Installation of network and signal cable
As already mentioned, the external power supply is usually connected to the indoor unit. Some manufacturers equip their models with a network cable of a certain length with a plug for an outlet, while others offer to do it on their own by connecting the network cable to a special electrical block inside the indoor unit housing. The first option is simpler, but less versatile. The length of the already mounted cable with a plug may not be enough to reach the outlet and you will have to somehow increase it, but in the second option, you can easily measure the length of the cable you need for installation, put the plug in or connect it directly to the junction box or cable from the electrical panel. When choosing a network cable, the minimum recommended is a three-core in a polychloroprene sheath with a cross section of 1.5 mm 2 (3×1.5), but it is better to install 3×2.5 mm2 – the air conditioner is a powerful device, and it is better to have a reserve.

The indoor and outdoor units are usually connected with one four- or five-wire cable, but there are models where two cables are required.


The cable is passed through the corresponding technological openings of the housing and is mounted with a terminal to the block in accordance with the diagram, which is usually pasted inside the block next to the block.


It is highly desirable to insert the fixed signal cable into a black corrugated PVC pipe if the installation is carried out in a concrete or brick base, or into a flexible metal pipe if the hole for the route is made in a wooden wall.


Installation of refrigerant pipes and drains
The air conditioning refrigerant supply pipes are located on the rear side of the indoor unit and have different diameters, it goes in a liquid state through a thin one, and in a gaseous state through a thick one.

The smaller tube has a diameter of 6.35 mm (1/4 inch), but the larger diameter depends on the capacity of the system: the higher it is, the larger the diameter. Typically, the diameter of such pipes for residential air conditioners is 9.52 mm (3/8 inch) or 12.7 mm (1/2 inch).


The pipes of the indoor unit are already equipped with fittings and special conical nuts, plastic plugs are installed on the pipes, when you remove them for the first time, you can often hear the sound of escaping gas, since the system is checked for leaks at the factory and remains under some pressure.


The route preparation process can be reduced to the following steps:

bending the tubes of the indoor unit in the desired direction
rolling refrigerant pipes and cutting with a pipe cutter
pipe bending
pipe insulation installation
flaring of pipe ends
connecting the pipes of the air conditioner and the route with nuts
drain hose extension
formation of a route consisting of: refrigerant pipes, drainage pipes, power cables of the outdoor unit
Let’s go through the steps.

When bending the tubes of the indoor unit in the right direction, this must be done carefully and smoothly without sudden movements so that there are no creases or dents. It is imperative to observe the condition that the connecting fittings with nuts at the ends do not end up outside the room or, even worse, inside the hole through the wall. Connections must be available for maintenance.

The refrigerant pipes connected to the air conditioner require no less careful handling. Slowly, roll them out and measure the desired length. An important point is that the minimum length of the route must be NOT SHORTER than three meters for inverter systems and two meters for non-inverter systems.


We use a special pipe cutter to cut the copper pipe. This is a small tool that rotates around the cut point and gradually cuts into the surface of the pipe with a sharpened disk. The cut is straight and clean.


After cutting, deburring at the edge of the cut is mandatory, since even a small metal chip inside the track contour can damage the air conditioner mechanism. This can be done with a small needle file or a special tool that cleans the chips from the inside of the cut. Be sure to shake everything out from the inside of the tube.


We make the location of the bends on the pipe in accordance with the markings. Bending copper pipes of small diameter (1/4) can be carefully done by hand, they bend easily, but for large diameters 1/2 you can not do without a pipe bender – a special steel spring with tight-fitting coils. The pipe bender is put on the pipe and then with our hands we gradually and with a sufficiently large effort form the desired bend.


After making the bends, we pull a heat-insulating cover onto the tubes.


After that, using a flaring kit, we form the connecting ends of the pipes. The tool consists of two parts: a pipe is inserted into the corresponding hole in the clamp, and then we make flaring with a screw block.


The most important thing here is not to forget to put a conical nut on the pipe before flaring. If the nuts are small and the diameter of the hole allows, then you can flare from both ends of the route at once, so that later you do not have to do it in a more uncomfortable position outside the wall.


Connecting the route to the indoor unit
After flaring, we connect the pipes to the indoor unit. We press the flared edge of the pipe to the fitting of the corresponding air conditioner pipe and tighten the nut. This is a very crucial moment, since undertightening the nut can cause freon leakage, and overtightening can damage the thin edge of the tube. In a good way, you need to use torque wrenches, but professional craftsmen who have made more than a dozen installations are limited to two keys, feeling the right tightening torque with their hands.


With a drainage tube, everything is much simpler: we simpl

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