A modern refrigerator is a complex system, the heart of which beats with the rhythm of compression and expansion of the refrigerant, providing the necessary temperature for your products. It is compressor that is the main engine of this process, causing freon to circulate through the tubes and take heat from the chambers. Understanding what types of compressors there are will help you not only choose a reliable model when purchasing, but also correctly diagnose faults in the future.
At first glance, all motors perform the same function, but the technologies for their implementation differ radically in noise levels, energy consumption and service life. If you are wondering why one unit operates almost silently, while the other makes a characteristic hum, the answer lies precisely in the design pressure unit. In this article we will analyze in detail the design of various systems, their advantages and disadvantages, so that you can become a real expert in choosing household appliances.
It is worth noting that manufacturers are constantly introducing new developments aimed at reducing vibration and saving energy. Digital inversion and linear drives have become the standard for premium segment, while classic piston models are still widespread in the budget segment. The difference in price between them can be significant, but whether it is justified for a particular user is up to you to decide after reading the material.
The principle of operation and the role of the compressor in the system
To understand the difference between the types of engines, it is necessary to briefly consider the basic principle of operation of the refrigeration circuit. The compressor draws in low pressure and temperature refrigerant gas, compresses it to increase the pressure and temperature, and pushes it into the condenser. This cycle is repeated continuously until thermostat or the electronic module gives a command to stop.
The most important parameter is performance, which depends on the volume of the cylinders and the speed of rotation of the engine shaft. This is where the main difference between the old and new models lies: the ability to regulate this speed or operate in a start-stop mode. The quality of the piston group or magnetic drive directly determines resource the entire refrigerator.
⚠️ Attention: An attempt to replace the compressor yourself without evacuation of the system and replacing the filter-drier will lead to rapid breakdown of the new unit due to moisture and debris in circuit.
The operating efficiency of the entire system is assessed by the cooling capacity coefficient. Modern energy efficient classes A++ and higher are achieved precisely by optimizing the operation of the motor and minimizing energy losses due to friction and heating. Understanding these processes allows you to consciously approach the choice of equipment, without overpaying for unnecessary functions, but also without saving on critical components.
Classic piston compressors
The most common and time-tested type is the piston compressor. Its design resembles a miniature internal combustion engine: an electric motor rotates a crankshaft, which drives pistons inside the cylinders. Such units are divided into crank and rocker units, where the movement is transmitted through a swinging rocker.
The main feature of the classics is operation in on and off mode. The motor starts at full power, cools the chamber to the set temperature and turns off. When the temperature rises, the cycle repeats. This creates a certain load on starting winding and the relay, which often causes failure of these particular elements.
- 🔹 High maintainability and availability of spare parts for most models.
- 🔹 Relatively low cost of the unit itself in comparison with innovative analogues.
- 🔹 Ability to work on various types of refrigerants, including R600a i R134a.
- 🔹 Sensitivity to voltage drops in the electrical network, requiring the use of a stabilizer.
Despite the apparent simplicity, piston systems can be quite noisy, especially at start-up. The vibration is transmitted to the body of the refrigerator, which sometimes causes resonance. However, for many users, the reliability and low cost of repairs outweigh these disadvantages, making piston models popular for decades.
Inverter systems: smoothness and savings
An inverter compressor is a modern standard in which the electric motor does not turn off completely after reaching the desired temperature. Instead, it simply reduces the speed to a minimum, maintaining temperature conditions in a narrow range. The rotation speed is controlled by converting direct current into alternating current at the desired frequency.
The absence of constant starting currents significantly extends the service life of mechanical parts. Such engines operate almost silently and consume significantly less electricity, since they do not waste resources on overcoming the inertia of rest each time they start. This makes them an ideal choice for kitchen studios and open spaces.
However, inverter systems also have their vulnerabilities. The main difficulty lies in the electronic control board, which is sensitive to power surges. Repairing such electronics can be expensive, and in some cases it requires replacing the entire refrigerator control unit.
It is worth noting that many manufacturers combine technologies to create hybrid systems. For example, digital inverter can have 7 power levels, which allows you to flexibly respond to the loading of chambers with products. If you open the door and put in a lot of warm food, the motor will temporarily increase power and then switch back to economy mode.
Linear compressors: magnetic drive
The linear compressor is an evolution of the piston system, but lacks the crank mechanism. Here the piston is driven by electromagnetic forces: a coil creates a magnetic field that moves the piston back and forth. The absence of rubbing parts in the drive makes the design very reliable.
Such units are often called linear inverter, since they are also able to regulate the speed of the piston. Due to the absence of rotating parts and friction points, vibration and noise levels are kept to an absolute minimum. This is a technology that LG is actively promoting, calling it Linear Cooling.
The advantages of linear systems are obvious: durability, quiet operation and high energy efficiency. They allow you to cool products faster and more accurately maintain set parameters. However, the cost of such refrigerators is usually higher, and fault diagnosis requires special equipment and qualifications.
Why are linear compressors so quiet?
A linear compressor does not have a rotating shaft and connecting rods, which create the main vibration in conventional motors. The piston moves in a straight line, and shock absorption occurs due to springs, which dampens mechanical vibrations almost completely.
It is important to understand that despite their high reliability, linear compressors are not without drawbacks. In case of failure of the magnetic system or windings, most often it is necessary to replace the entire assembly, since their disassembly and repair in domestic conditions is practically impossible.
Comparative table of characteristics
For ease of selection and understanding of the differences, we will summarize the main parameters in a single table. This will help you quickly figure out which type of engine is suitable for your operating conditions and comfort requirements.
| Characteristics | Piston | Inverter | Linear |
|---|---|---|---|
| Noise level | Medium / High | Low | Very low |
| Energy consumption | Standard | Economical (-30%) | Maximum economical |
| Work resource | 8-10 years | 10-15 years | 10-15 years |
| Repair cost | Low | High | High |
| Sensitivity to the network | Average | High | High |
As can be seen from the table, progress in the field of noiselessness and economy obvious, but it is accompanied by increasing requirements for the quality of power supply. If the voltage in your home often fluctuates, installing a high-quality stabilizer will become a prerequisite for the operation of modern equipment.
Typical faults and diagnostics
Even the most reliable refrigeration unit can fail. Most often, problems manifest themselves in the form of a lack of cold, constant humming or frequent switching on and off. The first sign of a compressor malfunction is often a hot motor housing in cold chambers.
If the motor hums, but does not start, and after a few seconds a click is heard, the start relay is most likely faulty or the piston group is jammed. In the case of inverter models, diagnostics are more complicated: it is often necessary to read error codes from the control board to understand what the problem is - in the motor or in the electronics.
☑️ Diagnosis of problems with the compressor
Another common problem is freon leakage. In this case, the compressor may work continuously, trying to gain temperature, but not cope with the task. Continuous operation of the motor without stopping leads to its overheating and eventual combustion of the windings, so it is important to notice the lack of cold in time.
Tips for extending the service life
In order for the compressor to last as long as possible, it is necessary to provide it with the correct operating conditions. First of all, this concerns ventilation: the back wall of the refrigerator should be at least 5-10 cm from the wall. Overheating is the main enemy of any electric motor.
Sudden changes in temperature should also be avoided. Do not place hot pots in the chamber and try not to open the door unless necessary. A sudden influx of warm, humid air forces cooling system to work at the limit, increasing wear of parts.
⚠️ Attention: If you plan to transport the refrigerator, be sure to secure the compressor with shipping bolts (if they are provided for in the design) or carefully fix shock absorber springs to avoid damaging the engine suspension.
Regular defrosting (for No Frost systems this is also useful in the form of a preventive shutdown for a day) helps maintain heat transfer in the evaporator, reducing the load on the engine. A clean capacitor on the back of the refrigerator also helps to effectively dissipate heat.
Frequently asked questions (FAQ)
Is it possible to replace a conventional compressor with a inverter?
Technically this is possible, but it requires replacing the control board, reconfiguring the system and is often not economically feasible. It’s easier to buy a new refrigerator, designed for inverter technology.
Why does a new refrigerator hum loudly?
In the first days of operation, parts are being ground in. Also check that the refrigerator is level and not touching walls or furniture. If the compressor is humming, and not the vibration of the housing, this may be a defect.
How long does a compressor last on average?
The average service life is from 10 to 15 years. Linear and inverter models with a stable voltage can operate for up to 20 years or more.
What to do if the compressor is hot, but the cold does not flow?
Most likely, there is a refrigerant leak or a capillary tube blockage. It is necessary to call a technician to find a leak and charge the system.
Does the temperature in the room affect the operation of the compressor?
Yes, at high room temperatures (above +32°C) the compressor works with increased load and may not turn off. At low temperatures (below +10°C), the oil in the compressor thickens, making it difficult to start.