The sudden decline in the effectiveness of climate engineering often comes as an unpleasant surprise in the midst of a hot season. The owner notices that the air stops cooling to comfortable values, and electricity bills begin to rise, although the mode of operation of the device has not changed. In the vast majority of these situations, the culprit is the problem. refrigerant leakageIt disrupts the thermodynamic cycle of the system.
Freon is a working body circulating in a closed circuit, and in good condition it should not be consumed or disappear with time. However, vibrations, temperature changes, metal corrosion and manufacturing defects can lead to depressurization of compounds. Microleakage This can happen for years until the system completely loses its properties, so early diagnosis is critical to preserving an expensive compressor.
Self-detection of the depressurization site requires an understanding of the physical processes occurring within the split system. It is important to note that modern refrigerants such as R410A or R32They have a high penetrating ability and can escape through microscopic cracks that are invisible to the eye.
Ignoring the primary signs of malfunction often leads to failure of the main unit - the compressor, which is cooled and lubricated with circulating freon and oil. Work on "dry" or with insufficient gas causes overheating of the windings and jamming of the piston group, which makes repair economically inexpedient.
⚠️ Attention: Freon is heavier than air and with a large leak in an enclosed room can displace oxygen, which creates a risk of suffocation. In addition, when exposed to an open flame, many refrigerants form toxic compounds.
The main signs of a lack of refrigerant in the system
The first and most obvious signal to the user is a decrease in the performance of the air conditioner. The device continues to drive air, but the temperature at the exit from the inner unit ceases to fall below 16-18 degrees, even when setting the minimum values on the remote. The compressor can work continuously without going into standby mode, which indicates the inability of the system to type the specified parameters.
Visual inspection of the external and internal units can also provide important clues about the state of the system. On tubes, connections or heat exchanger often appears frost or ice coat, which is physically impossible at normal pressure and the amount of refrigerant in the circuit. Oily spots around soldering sites or on the compressor body indicate that compressor oil leaves the system with the gas.
- ❄️ The appearance of an ice crust on copper tubes or a heat exchanger of the inner unit.
- 📉 Reducing the force of air flow from diffutors with a running fan.
- 💧 Condensation and dripping of water from the inner block due to freezing of drainage.
- 🔊 The appearance of hissing sounds indicating the gas exit under pressure.
An indirect sign can serve as a strange behavior of electronics. Modern inverter systems, such as Daikin Emura or Mitsubishi ElectricThey are equipped with sensors that detect anomalies in the operation of the compressor and can issue error codes associated with overheating or low suction pressure.
⚠️ Warning: If you notice that the air conditioner has started to throw out warm air instead of cold air, stop operating it immediately and turn off the power to prevent the compressor from breaking down.
Visual method and soap solution testing
The most affordable and common method of primary diagnosis, which does not require complex equipment, is the use of a soap solution. This method is effective for finding leaks in places of threaded connections, connections and service ports, where tightness is most often broken due to vibrations.
To carry out the procedure, it is necessary to prepare a concentrated solution of water and household soap or a special means to search for leaks. Applying the foam with a brush to suspicious areas, you should carefully monitor the surface: at the exit point of the gas, characteristic bubbles will inflate, which increase in size.
Particular attention should be paid to roller joints that are outside the insulation. If the tubes are covered with thermal insulation, it must be carefully cut or pushed away at the joints.
- 🧼 Carefully clean the surface of dust and dirt before applying the solution.
- 🔍 Examine the connections in good lighting using a flashlight for glare.
- ⏱️ Leave the foam for 3-5 minutes, as with a small leak, the bubble grows slowly.
After detecting the leakage site and fixing the malfunction (replacement of the gasket, nut lift or soldering), it is necessary to re-check the connection under pressure. This ensures that the problem is completely solved and the system is ready for vacuuming and refueling.
Use of a professional flow detector
For more accurate and quick diagnosis, especially in hard-to-reach places, the master of service services use electronic flue-finder. These devices respond to changes in air chemistry by capturing even the minimum concentrations of halogen-containing gases, which include most refrigerants.
The principle of operation of the device is based on the transmission of air through a special sensor. When Freon vapors enter the sensor, the conductivity or frequency of the sound signal changes, which allows you to precisely localize the exit of the gas. Modern models such as Inficon or RobinairThey are able to differentiate the types of freons and have sensitivity adjustment.
The search process begins with the blowing of all connections, starting with the compressor and ending with the evaporator. The speed of movement of the probe should be minimal (about 2-3 cm per second) so that air can get into the sensor chamber. When a leak is detected, the device emits an intermittent squeak or the indicator lights up.
Why can a leak detector lie?
Electronic sensors are sensitive not only to freon, but also to vapors of alcohol, deodorants, solvents and even cigarette smoke. If the room has been repaired or used chemistry, the device can give false signals. Before work, it is necessary to ventilate the room and let the device warm up in clean air.
⚠️ Warning: Before using the leak detector, make sure that there are no drafts in the room that can carry Freon vapors away from the leak site, which will make it much more difficult to find.
Method of ultraviolet diagnostics
One of the most reliable ways to find hidden leaks is to use the ultraviolet (UV) method. To implement it, a special fluorescent dye must be added to the system along with oil or freon. After the substance circulates in the system for some time, the leak sites begin to glow under the influence of the UV lamp.
This method is particularly effective for finding microleaks that cannot be detected by a soap solution or a conventional leak detector. The dye accumulates at the gas outlet and forms a bright glowing mark, visible even in low light. The lamp with a wavelength of 365-395 nm and safety glasses are required.
The advantage of the method is the ability to detect leakage in the heat exchangers of the evaporator or condenser, access to which is limited. The dye penetrates into the smallest cracks and stays there, highlighting the problem area with a bright yellow-green color.
☑️ Tools for UV diagnostics
It is important to use only those dyes that are compatible with the type of oil and freon in your system. For example, for polyester oils (POEs) used with freon R410ASpecial compositions are required that do not react with the system components.
Exclusion diagnostics and standard table
Sometimes visual methods and devices do not give a result, and then indirect diagnostics on the parameters of the system comes into play. The wizard measures the pressure in the circuit, the currents of the compressor consumption and the temperature at the inlet and outlet of the evaporator, comparing them with factory norms.
The key parameter is overheating suction. If there is little freon in the system, it evaporates completely in the evaporator and is further heated before it reaches the compressor. High overheating at low pressure clearly indicates a lack of refrigerant.
| Parameter | Norm (R410A) | Sign of leakage | Unit of measurement |
|---|---|---|---|
| Suction pressure | 6.5 - 8.0 | Below 5.5 | barbar |
| Temperature at the evaporator output | +5..+10 | Above +15 | °C |
| Overheating (Superheat) | 5 - 8 | Above 12. | kelvin |
| Compressor current | By nameplate | Below the norm | Ampere |
Analyzing this data, we can conclude about the state of the system even without detecting the visible leak site. If the pressure drops and the overheating increases, then there is not enough working body in the circuit, and the search should be continued with more careful methods, perhaps with a rise in pressure with nitrogen.
Complex diagnostics by parameters (pressure, current, temperature) is often more informative than the search for a leakage site, since it confirms the fact of loss of tightness of the system.
Procedure after detection of leakage
Once the leak site is found, you can't just add freon to the system. The residual gas must be completely removed and then the circuit must be vacuumed to remove moisture and air. Only after the creation of a deep vacuum is soldering or replacement of the damaged element.
If the leak was significant and the system worked in a long time in a depressurized state, it is recommended to replace the dehumidifier filter. This element collects moisture from the circuit, and upon contact with the atmosphere it quickly saturates, ceasing to perform its function, which can lead to the formation of acid in the system.
- 🔧 Dismantle the damaged area or make repairs (pleasing, replacement of the seal).
- 🌬️ Blow the system with nitrogen to remove combustion products and contaminants.
- 🔻 Evacuate for a minimum of 30-40 minutes.
- ⚖️ Fill the system with freon strictly by weight, according to the specification.
Always weigh the Freon cylinder before and after refueling. Refueling "by eye" or pressure in the heat can lead to improper operation of the system and breakdown of the compressor.
The final stage is the control start and check all parameters under load. Convinced of stable operation and the absence of leaks, the master restores thermal insulation and decorative boxes.
Can I fill the air conditioner with Freon?
Theoretically, this is possible with the presence of equipment (gauge station, scales, vacuum pump), but without qualification, the risk of spoiling the equipment is high. The wrong amount of Freon or the presence of air in the circuit is guaranteed to bring the compressor out of action.
How often should I check the air conditioner for leaks?
Preventive examination is recommended every 1-2 years. If the air conditioner is more than 7-10 years old, checks should be done annually, since the metal pipes and ossicles lose elasticity over time and are subjected to corrosion.
How much does it cost to find and fix a leak?
The cost consists of diagnostics, the cost of materials (freon, oil, solder) and the difficulty of access to the leakage site. On average, taking into account refueling, repairs can cost 30-50% of the cost of new equipment of budget class.
Why did the leak happen again after the gas station?
This means that the original cause has not been eliminated. The master could find one leak site, but there could be several in the system, or repairs were carried out poorly. It is also possible that the vibration caused a new crack near the repair site.