Repair of household and industrial air conditioners and split systems

Relatively recently, air conditioning was a complex and costly procedure due to the technical imperfection of the systems. Climatic installations were an industrial attribute, they were extremely rare in everyday life. The development of technology has dramatically changed the picture, and now air conditioning is equally common in a cafe and a store, an apartment and a cottage, an office and a hospital.

Such prevalence sharply marked the conditions for the development of the HVAC equipment maintenance network, since the repair of industrial air conditioners supplemented the repair of household ones. The service is quite well developed, but often users are faced with the need to troubleshoot themselves in order to save time. It is important to correctly assess your strength and clearly understand what you can do yourself, and where you need a trained repairman. For this, it is necessary in general terms to present the principle of operation of technology and the system of its classification.

The device and layout diagrams of the air conditioner

An air conditioner has a lot in common with a refrigerator (or heat pump). The difference is in the design of individual units and some specific details. The principle of operation in all cases remains the same.

A portion of a volatile substance - refrigerant - enters the evaporator. The compressor creates a vacuum in the evaporator causing the refrigerant to evaporate, cooling the system. The cooler is collected in the condenser, already with the release of heat. To distribute the resulting cold and dissipate excess heat, two fans are provided.

In some designs, four-way valves are installed that switch the direction of the refrigerant flow. When the evaporator and condenser are swapped, the system starts to work for heating. It is important to understand that the air conditioner cannot become a full-fledged heater - it is able to utilize low-calorie heat as long as there is a temperature gradient between the environment and the evaporator. The lower the outside temperature, the more helpless the air conditioner becomes as a heater. It is more efficient to use it as ventilation, so many models have air purification and filtration units.
According to the type of assembly of nodes, all models are divided into two types:

• Monoblock. The evaporator and condenser are located in one housing. A window air conditioner is designed according to this scheme. The advantage of the design: simplicity, low cost, easy installation and reliability. Repair of mobile air conditioners is required at times less often than separate systems. Among the disadvantages is the high noise level.
• Split system. Due to the high noise level, monoblock structures began to be divided into two blocks - condenser and evaporative. The evaporating part is placed indoors, and the condensing part, as the noisiest part, is placed outside the room. Both units are connected by tubes and electrical wires. The virtues are silence. The disadvantage is the complexity of the installation.

All climatic equipment is divided according to the type of specialization:

• Domestic. Designed for small spaces. Several options for execution. The split system implies a wall option. Monoblocks - window and floor. A good option for an apartment or a small cottage, office.
• Commercial. Designed for a large area: a large cottage or cafe, office, public building.The main difference from the household one is power and a greater variety of performance. Ducted: the flow of cooled air spreads through the duct system, and the cooler itself is hidden from prying eyes. Cassette: a suspended ceiling segment that can carry out point air conditioning. There are other options as well.
• Industrial. Some disregard for external design and focus on quality. Works on large areas and volumes. There are a lot of options. The column air conditioner generates a convection flow with a radius of ten meters or more. Multi-zone can create a different microclimate with great accuracy in specified areas.

All installations work the same, regardless of whether it is an apartment or an office option. There is approximately one diagnostic and repair algorithm.

The main types of problems and their diagnosis

The causes of malfunctions, as well as their symptoms, can vary greatly. Problems can be conditionally divided into three main categories:

• Decreased performance or general system breakdown leading to incorrect operation.
• Mechanical faults.
• Electrical damage.

There are two main reasons for a decrease in performance: Freon leakage due to a leak in the circuit, or insufficient maintenance - dust contamination of the filters and radiators of the evaporator or condenser. The chance of repairing the system yourself is very low.

If the air conditioner rarely shuts down and works with obvious overload, consuming a lot of electricity, it is most likely a matter of pollution. Especially if the unpleasant smell of burnt dust is felt. In this case, the repair of split systems is quite simple: you need a thorough cleaning.

There are several important rules when repairing an air conditioner:

1. All manipulations can be carried out after the device has been de-energized and made sure that there is no voltage.
2. No brute physical strength. Most models require a minimum of tools to disassemble. Almost all fasteners are on snaps and tides, so they can be removed simply by hand.
3. If there is no understanding and self-confidence, you should not repair the household air conditioner yourself. It is better to call a wizard who can fix the system without loss.

Lack of service

In the indoor unit, the filters that are behind the outer panel are removed. They are washed in warm water with the addition of non-aggressive detergents, for example, ordinary liquid soap. It is recommended to check the manual first.

When cleaning the fan and fins of the evaporator radiator, you need to be careful - the plates are very thin and soft, they can be easily damaged. It can be washed with a very soft brush with warm water and special detergents. It is convenient to use a steam generator to remove dust build-up inside the air conditioner.

The external block of the split system is washed according to the same principle.

If cleaning does not help or the air conditioner starts to hum too loudly during operation, you need to check for refrigerant leaks. This is done with a special pressure gauge with the fan and compressor running. The absence of a predetermined value of pressure in the system indicates a leak and a shortage of freon.

First, look for the leak. There are two main ways:

• the system is filled with nitrogen and the gas analyzer is found where the line is depressurized;
• if the manufacturer has added a special indicator to freon that glows in ultraviolet light, lamps of the required spectrum are used.

After the elimination of the violation in the line, the system is refilled with freon. This should be entrusted to a specialist, otherwise the cost of repairing an air conditioner may increase significantly.

Mechanics

The main mechanical failure is the appearance of condensation. Since the relative humidity of cold and warm air is different, condensation is inevitable.There is a special drainage tube to drain it. If water begins to appear in the room, check the outlet hose. In winter, blockage can occur due to ice plugs. Installation of a special heating circuit will help.

In summer, the cause of blockage can be dust, fluff, insects. Blowing with compressed air helps. A bicycle pump will suffice.

Electrical part

If the remote control stops working, but the air conditioner reacts to commands from the panel, check the quality of the batteries. If the system malfunctions without the participation of the remote control, it is necessary to check the parameters of the supply network. If the voltage at the outlet is not correct, or there are surges, they can cause malfunctions. Exit: install a surge protector and an uninterruptible power supply.

Most air conditioners are equipped with a warning system. In case of basic typical malfunctions, they are signaled by flashing the LED at a certain frequency and frequency. Any error has its own code. Approximate decoding of signals by the number of flashes:

• 1 - malfunction of the indoor unit thermistor.
• 2 - the outdoor unit thermistor needs to be replaced.
• 3 - the circuits work simultaneously for heating and cooling. The main reason is a malfunction of the switching relay or tap.
• 4 - overload protection blocking.
• 5 - lack of information communication between the blocks.
• 6 - power consumption is above normal, power transistors should be checked.
• 7 - dangerously high voltage in the external unit.
• 8 - the fan drive is faulty.
• 9 - the valve responsible for changing the heating-cooling mode does not work.
• 10 - no temperature control on the outer wall of the compressor. We need to check the thermistor.

Preventing malfunctions

Prevention of malfunctions begins at the stage of equipment selection and installation: it is important to follow all the manufacturer's recommendations. You do not need to force the air conditioner to do what it is not designed for. For example, heat an apartment at subzero temperatures.

Take good care of electricity. If there are surges and falls in the network, a filter and a UPS are required. Grounding is also required - even static voltage on the case can cause electronics failure.

Observe the frequency of cleaning the filters. A clean filter is clean air that users breathe.