How to properly install an air conditioner on a load-bearing wall: rules + technological sequence

If you decide to install and connect a brand new air conditioner yourself, you need to know all the technological features and subtleties. After reading this article, you will learn how to properly install an air conditioner on a load-bearing wall so that there are no problems in operation or maintenance.

Knowing all the specifics of the work, you will be able not only to supervise the hired craftsmen, but also to do everything yourself. Considering that installation typically costs as much as half an air conditioner, this is a chance to save a lot of money.

Here you will find tips on choosing a location for each block. We described all the nuances of installation, provided a list of everything necessary with options for replacement with improvised means. They offered detailed instructions for installing the air conditioner, an analysis of possible errors and a video of the entire process that will help even a beginner.

How to choose a location for an air conditioner?

Not only the comfortable microclimate in the house, but also the health of the residents and longevity depend on the correctness of this decision. split systems, the amount of bills for electricity and for servicing the unit. In addition, in the case of load-bearing walls, mistakes can result in problems with BTI and other offices, and sometimes even in the collapse of the building.

To avoid all the negative consequences described, when choosing the location and method of installing the air conditioner, you should take into account many factors - we’ll talk about them later.

Limitations for load-bearing walls

Load-bearing walls are the thickest in the house; the main load is distributed on them; damage to their structure threatens the safety of all residents.

You can determine whether the selected wall is load-bearing by looking at the passport with the apartment plan - there they are highlighted in bold

External walls are always load-bearing, and therefore there is no choice for an outdoor air conditioner unit. Many owners try to hide the communications of the indoor unit in the wall for aesthetic reasons. To do this, you will need a groove 4–7 cm deep.

The reinforcement in load-bearing walls is placed only 3–4 cm from the wall surface. This means that the reinforcement will have to be cut out - and this is dangerous, and is also prohibited by SNiP 3.05.06 - 85. The ban on deep grooves also applies to brick load-bearing walls: although they do not have reinforcement, there is a significant reduction in thickness, especially on horizontal segment, negatively affects resistance to loads.

Does this mean that it is impossible to install air conditioning and communications in a load-bearing wall safely and legally? Of course not.

There are several possible solutions:

1. Laying the main line in a box is the most common and universal option; it is also used in the case of installing an air conditioner after finishing the walls;
2. Mounting the units back to back is only possible when the air conditioner is hung on a wall facing the street.
3. Laying air conditioner routes into a false wall, column, or other decorative structure on a plasterboard wall or ceiling.By covering the entire wall with plasterboard, you can at the same time organize soundproofing from neighbors or insulation.

If you do not intend to sell, inherit or make other transactions with the apartment, it is likely that illegal wall cutting to install an air conditioner will go unnoticed and unpunished.

Arranging a groove, especially in reinforced concrete, significantly increases the cost of installation, and unscrupulous craftsmen may tempt you to this option

However, we strongly recommend that you do not do this for your own safety - you are the one living in this house, not the installers.

Where to hang the outside?

The efficiency and economy of the split system largely depends on the operating conditions of the outdoor unit and the length of the route. The better it cools and the closer it is, the easier it is to provide cool housing.

Firstly, the external part of the split system must be installed securely. External walls are load-bearing, thick, and almost always suitable. Difficulties may arise due to insulation or a ventilated façade; mounting to an aerated concrete wall also requires special attention. It is permissible to place only low-power models weighing 10 - 15 kg on the balcony fencing.

Secondly, it will be much easier for the condensing unit to work in the shade, on the north or east side. In addition, the compressor and radiator must be well blown with air from all sides, so it is important to follow all the indentations specified in the instructions. Usually it is 10 - 30 cm from the wall and on the sides, 60 cm in front and above, at least 2 m from the ground.

Third, air conditioner outdoor unit should be located within reach, but not interfere with either you or your neighbors.

Remember that the condenser needs to be serviced periodically: cleaned, refilled, possibly repaired, and it is unreasonable to hire industrial climbers for this every time

Good places to install the outdoor unit:

• under the roof overhang;
• on an unglazed balcony;
• near the glazed balcony;
• under the window, if the drainage tube can be moved to the side;
• on the roof, if the route is no more than 10 - 20 m, depending on the model.

The last thing to consider is the drainage of condensate from the indoor unit. According to regulations, it should be discharged into the sewer system, but in practice this is extremely rarely possible. The tube is most often simply placed outside, under the outdoor unit.

In this case, it is necessary to ensure, firstly, that it is lower than the indoor unit. And secondly, so that water does not fall on passers-by, windows and walls. You can lead the drainage pipe separately from the main line between the blocks, simply along the shortest path to the street, with a slight slope.

Where to place the indoor unit?

The indoor unit also cannot be hung in a corner; it is necessary to step back at least 12 cm to the side and 10 - 30 cm from the ceiling, the exact numbers are indicated in the instructions. When installing on a load-bearing wall, it is especially important to choose a location closer to the street wall in order to minimize the length of the route in the box.

When choosing an air conditioner, you should pay attention to which side the communications come from, this will make installation more convenient. In some models, the connection side can be selected

You cannot hang the air conditioner above a radiator, in a kitchen or other room with electromagnetic interference, behind a curtain, above a closet, above a bed or workplace. In the latter case, you are guaranteed to get regular colds; in the rest, the unit will not be able to work effectively and may soon fail.

What will you need for self-installation?

High prices for professional installation are usually explained by the use of expensive professional tools, as well as the danger of the work. But this is only partly true, so if you are not ready to pay a tidy sum for a couple of hours of professional work, you can do it yourself.

Specialized tools can be rented at a hardware store, and consumables can be purchased at the same place that sells filters and spare parts for air conditioners.

Tools: professional or improvised

To secure both blocks you will need a hammer drill and a level, it is also advisable to have a drill or screwdriver. Using a hammer drill, you need to punch holes not only for fasteners, but also for connecting communications. That is, you need a drill or cutter with a diameter of 50 - 80 mm, depending on the model of the air conditioner. If there is no building level, it can be replaced with a piece of transparent hose with water.

It is convenient to fix the mounting plate of the indoor unit to a brick or wooden wall with a drill or screwdriver, but you can get by with a hammer drill and a screwdriver

If you plan to connect to the electrical network directly, without an outlet, you will need an indicator and a tester so as not to mix up the wires and check the operation without burning the air conditioner control board.

It is also advisable to have a pressure gauge to check the freon pressure after installation.

The most necessary professional tool is a set for processing copper tubes. It includes a pipe cutter, a rimmer or chamfer, and a roller. Theoretically, the first 2 can be replaced with a hacksaw, a file and sandpaper, and in the rental you can only look for a roller to create a bell.

However, in practice, this leads to metal shavings getting into the tube, and then into the compressor, which causes its failure. In addition, if bends, dents and burrs are not removed from the cut, after flaring the edge of the pipe will not be smooth, and the smallest cracks will spread over time and lead to freon leakage.

Another specialized device is a vacuum pump, which is necessary to remove air, moisture and dust from the system before the first start-up. If you can’t find it, or renting it is too expensive, you can replace it with a compressor from an old refrigerator or a supercharger from an aquarium paired with a pressure gauge.

In the absence of such equipment and the short length of the route, you can simply release a little freon before starting so that it displaces everything unnecessary.

If you neglect to vacuum the system, the freon will be diluted with air, which reduces the efficiency of the air conditioner. Debris and moisture remaining in the tubes after installation lead to rapid breakdown of the compressor, the replacement of which is expensive

If you decide to install an outdoor unit yourself at a height of more than 2 m, be sure to obtain insurance. When working from a stepladder, call at least 1-2 assistants: the capacitor is quite heavy, lifting it and placing it on the brackets is not an easy task.

Consumables and their selection

Before starting installation work, you need to check the equipment of the air conditioner and buy consumables. As a rule, the kit includes only the unit itself with instructions; even batteries for the remote control need to be purchased.

However, some models include copper tubes for the freon line, and there may also be a wire with a plug for plugging into an outlet.If this is your case, check the length of the tubes; if they are not enough, buy new ones for the entire length, and not just the missing section.

For electrical purposes, you will definitely need a wire with a cross-section of 2 - 2.5 square meters. mm. For 2 – 4 cores, depending on the model, to connect the external unit to the internal one. Take the length with a margin of at least 0.5 m, so that after stripping and laying it will not be stretched.

You also need to take care of connecting the indoor unit. You will need a wire to the nearest junction box and to the air conditioner, an automatic machine, possibly a socket, a plug, a box for external wiring.

There are 2 options: with and without a socket. A circuit breaker is mandatory in the second case, but also highly desirable in the first case - as a fuse

L-shaped brackets are usually used to secure the outdoor unit. They must be designed for a load 5 times greater than the weight of the device. Don’t forget to stock up on dowels with self-tapping screws and anchors to secure not only these brackets and the unit itself to them, but also the mounting plate of the indoor unit.

For the route you will need two seamless thick-walled tubes of different diameters made of soft copper for freon. Their edges should be sealed from the factory to prevent dust from getting inside. The exact diameter can be found in the instructions, and the length is equal to the length of the route plus 1 m in reserve, because you cannot connect them to lengthen them.

Copper tubes require insulation - foam rubber sleeves of the appropriate diameter and length.

Do not forget about the condensate drainage tube - a corrugated hose or polypropylene tube. If it needs to be long or will turn upward at any point, you will need a sump pump.

In order to disguise the pipeline without thinking about how to trench a load-bearing wall for an air conditioner, buy a plastic box. It is much easier to mount it on the walls to disguise communications.

For the box there are decorative overlays for the entries into the indoor unit and into the wall, rotary corners and other elements

If not the entire route will be placed in a box, it is advisable to wrap it with metallized tape.

Additionally you can purchase protective visor, anti-vandal cover and winter kit for the outdoor unit, but these are not required components.

Installation procedure and technology

Statistics say that the vast majority of split system breakdowns, as well as their incorrect operation, are completely or partially caused by installation errors. If you are ready to approach the issue meticulously and responsibly, and can get the necessary tools and equipment, then self-installation will not only help save money, but will also protect irresponsible craftsmen from making mistakes.

So, if the air conditioner is nearby in the box, the instructions for it have been studied, all the necessary tools and materials are ready, you can begin installation.

Preparatory work and indoor unit

Having chosen a place for the indoor unit, connect the electrics to it. It is advisable to pull a new cable from the panel, or at least from the nearest junction box. In order to avoid getting into fittings or wiring when making a hole for a machine or socket, it is advisable to first ring the wall with a wiring detector or at least a metal detector.

If possible, it is better to place the machine on an adjacent wall that is not load-bearing. Don’t get carried away by the desire to hide everything as much as possible: the socket and circuit breaker must be within reach, without stools or stepladders.

To minimize dirt and dust in the apartment, when working with a hammer drill, ask someone to hold the pipe of a vacuum cleaner turned on without an attachment nearby.

While the air conditioner is packed, you need to do the dirtiest work:

• Mark the wall: where the internal block will be, from it there is a route to the external one with a slope of 1 - 3%, where there is an exit to the street.
• If you still decide to ditch a load-bearing wall, now is the time.
• Punch a hole to the street of the required size, based on the thickness of the two copper pipes in the insulation, the cable and the drainage pipe combined. It is also advisable to make it with a slight slope towards the street, or with a margin in diameter.
• Remove the mounting plate from the indoor unit, attach it to the wall and level it strictly horizontally. If necessary, use a pencil to transfer the attachment points and outline onto the wall.
• Prepare the holes and securely fix the mounting plate.

Already at this stage, you can hang the indoor unit and check the level again. The slightest distortion threatens condensate stagnation and compressor overload, so don’t be too lazy to redo everything if necessary.

Fix the base of the box to the wall, not forgetting the slope. When everything is ready, it’s time to sit down to relax and admire the installed unit, because the hardest and most important work lies ahead.

How to install the outdoor unit yourself?

The easiest way is to hang the split system condenser unit on an unglazed balcony yourself.

In other cases, you need to securely tie yourself with a safety net and hang from a window or balcony, first with a hammer drill in your hands, and then with an outdoor unit

Taking care of safety, mark the brackets on the wall. Check the width of the fasteners on the block itself and mark the mounting points for the brackets. Make sure that they are strictly at the same level horizontally: misalignment of the outdoor unit is just as dangerous as that of the indoor unit.

After installing the brackets, carefully secure the outdoor unit to them, observing the distance from the wall recommended by the manufacturer. Remember that you cannot drill additional holes in the brackets: this significantly reduces their load-bearing capacity.

Check the horizontal position of the installed block both along the wall and perpendicular to it.

Main line laying and connection

When both blocks are installed, it's time to connect them with a route. This is the most critical part of the work, because errors in the preparation and installation of copper pipes can lead to a decrease in efficiency, freon leakage or compressor failure.

Before breaking the seal of copper pipes, remove dirt from the room after working with a hammer drill. Unwind the coils of tubes and straighten them. Measure the length required for the main line and cut 1m more - with a margin for bending and rolling not on the first try.

Work the inner surface of the cuts with a rimmer, holding the tube end down. This way you will remove the skirt - the edge is folded inwards, and the chips will not get into the tube. Then put on the nut, threaded to the end, and secure the tube in the corresponding groove of the roller.

Rolling a copper tube does not require much effort, because it is a soft metal, and a special limiter will help you avoid overdoing it.

If the finished socket has the slightest crack or other defect, it is necessary to cut off the stretched section of the pipe and repeat everything from the beginning.If the outdoor unit is installed in a convenient place, it is advisable to open and flare the second end of the tube already outside, after laying the route.

When both tubes are flared, put insulation on them. Then lay out in parallel both copper tubes in the insulation, a condensate drainage tube and a cable for connecting the blocks. The drainage pipe should protrude 60–80cm from the wall. If necessary, do not forget to install a pump. Wrap everything tightly with metallized tape, combining it into a single line.

If everything will be placed in a special box with clamps, it may be more convenient to lay everything separately, in parallel, so that the route is flat. In this case, only the part that will be laid along the street is wrapped with tape, without the box.

Having brought one end of the line through the hole to the street, put the rest in a box and secure it with clamps. Connect all pipes to the indoor unit. Do not overtighten the nuts on the copper piping. A heat shrink sleeve may be needed to connect the drainage tube.

To make it easier to connect copper pipes, place something under the bottom of the indoor unit, tilting it away from the wall

Then remove the front panel and connect the electrical according to the instructions.

There is a cover on the side of the outdoor unit, under which there are terminals for connecting wires, and sometimes a connector for copper pipes. Connect everything according to the markings, as on the indoor unit. Attach the drain tube under the bracket.

Preparing for launch and checking

When all connections are made, check them for leaks using soap suds and a bicycle pump connected to the freon charging fitting.

Then connect the vacuum pump and run it for about 1 hour until a vacuum is formed. Then the pump is turned off and the valve is closed with a plug, and both valves are fully opened so that freon from the condenser can flow into the evaporator. If the line is long, freon will need to be refilled - you can check the pressure with a pressure gauge.

The air conditioner is connected to the network, and it should enter test mode on its own. Some models have a separate button or combination on the remote control for this - look in the instructions. Only after finishing the test mode can you fill the hole in the wall and assemble the decorative parts of the box - and be proud of the work done.

Conclusions and useful video on the topic

To better imagine the whole process, we suggest watching how professionals install a split system:

And this video describes in detail the most critical stage - flaring copper tubes:

To summarize, we note that it is quite possible to install a split system on a load-bearing wall yourself, and you won’t have to ditch it. If you could not find a piece of equipment, or are not confident in your abilities, try to negotiate partial installation with the craftsmen. For example, you can install the blocks yourself and entrust the laying of the route to specialists, or you can connect everything yourself, and leave the master only with vacuuming, refueling and the first start.

How do you plan to install the air conditioner? Do you think it is acceptable to ditch load-bearing walls? Perhaps you have experience installing a split system? We look forward to your additions, questions and impressions in the discussion block below.