The heart of any The refrigeration unit is precisely the compressor, the operation of which determines the stability of the temperature regime and the service life of the equipment. Without this unit, circulation of the refrigerant is impossible, which, passing through a system of tubes, takes heat from the chambers and releases it into the environment. Understanding what types of refrigerator compressors areis necessary not only when purchasing new equipment, but also when diagnosing malfunctions of old equipment.
The modern market offers many modifications, each of which has its own design features, advantages and disadvantages. From classic piston mechanisms to high-tech inverter systems, the choice affects noise levels, energy consumption and maintenance costs. In this article, we will analyze in detail the design of various types of engines so that you can make an informed decision.
The principle of operation and purpose of the compressor
The main task of the device is to compress and pump gaseous refrigerant. The motor creates excess pressure in the condenser, where the gas turns into liquid, giving off heat. Then, passing through the capillary tube and evaporator, freon expands sharply, boils and absorbs heat from the interior of the chambers. This cycle is repeated continuously, maintaining the specified parameters.
It is important to understand that compressor power must strictly correspond to the volume of the chambers and the thermal insulation of the housing. If the engine is too weak, it will run non-stop trying to reach the target temperature, causing rapid wear. Conversely, excess power will cause frequent switching on and off, which also negatively affects the service life of parts.
Structurally, most models are a sealed casing, inside which an electric motor and a mechanical part are located. This arrangement allows minimizing freon leaks and reducing noise levels. However, different manufacturers use different technologies for implementing mechanical compression, which gives rise to a variety of types.
⚠️ Attention: The sealed compressor housing cannot be opened at home without special equipment and skills. There may be oil under pressure inside, and moisture or air entering the system will instantly damage the refrigerator.
Piston compressors: classics of the genre
The most common type that can be found in the vast majority of refrigerators produced over the last half century. The operating principle is based on the reciprocating movement of the piston inside the cylinder. The electric motor rotates the crankshaft, which through the connecting rod transmits movement to the piston that pumps the refrigerant.
Piston compressor is distinguished by its high maintainability and relative simplicity of design. If a valve group or start relay fails, these parts can often be replaced without replacing the entire unit. However, the presence of many rubbing parts requires high-quality lubrication and creates a certain level of vibration.
There are modifications with one, two or even four pistons. Multi-piston systems allow for smoother control of performance, although single-cylinder models are most often found in the household segment. They are reliable, but they create a characteristic noise during startup and operation.
Why are piston models noisy?
When the piston operates, an inertial force arises, which is transmitted to the body. If the shock absorber mounts are worn or the compressor is not installed level, the noise level will increase significantly. In addition, when closing, the valves emit a characteristic click, which is the norm for this type of equipment.
Rotary and crank-cam mechanisms
Unlike piston analogues, in rotary models compression occurs due to rotation of the rotor. The motor shaft is connected to a roller that rolls along the inner wall of the cylinder. A special plate separates the areas of high and low pressure, moving synchronously with the rotor.
This design provides more compact dimensions and a lower level of vibration. Rotary compressor often used in small-volume refrigerators or in No Frost systems, where the dimensions of the engine compartment are important. The absence of connecting rods and piston pins reduces the number of friction points.
However, the requirements for build quality and system cleanliness are higher here. The ingress of solid particles or the formation of an acidic environment due to moisture can quickly destroy the sliding pairs. Therefore, when replacing such a unit, evacuation of the system is critical.
- 🔄 High shaft rotation speed ensures rapid cooling.
- 📉 Fewer parts reduce the likelihood of mechanical breakdowns.
- 🔇 The noise level is lower compared to classic piston models.
- ⚙️ Sensitivity to the quality of the refrigerant and the absence of impurities.
Inverter compressors: modern technologies
This is the most progressive type of engine, which is radically different in the way it is controlled. If conventional motors operate in a “start-stop” mode (turn on at full power and turn off when the temperature is reached), then inverter compressor never stops completely. It smoothly changes the rotation speed, maintaining the temperature regime.
The main advantage is energy efficiency and silence. The absence of constant starting currents extends the service life of the electrical part. The refrigerator operates in the background, barely audible, and only when opening the door or loading warm food does it increase power.
Despite the high reliability, repairing the electronics of such models can be expensive. The inverter control board is sensitive to power surges in the network. Therefore, owners of such equipment are recommended to use voltage stabilizers.
Linear compressors: linear efficiency
Deserve special attention linear compressors, which are often confused with inverter compressors, although the principle of their operation is different. There is no rotational movement here. The piston is driven by electromagnetic forces, moving back and forth in a straight line. This eliminates friction points characteristic of crank mechanisms.
This technology allows achieving record low levels of noise and vibration. The design is as simple as possible: a minimum of parts means a minimum risk of breakdown. Linear models are often used in premium refrigerators, where a service life of up to 20 years is stated.
However, the production cost of such units is high, which is reflected in the price of the final product. In addition, in the event of a malfunction, a complete replacement of the unit is most often required, since repairing individual components is not economically feasible.
| Compressor type | Noise level | Energy consumption | Operating life |
|---|---|---|---|
| Piston | Medium/High | Standard | 10-15 years |
| Rotary | Low | Economical | 10-12 years |
| Inverter | Very low | Highly economical | 15-20 years |
| Linear | Minimal | Highly economical | 20+ years |
Comparison of characteristics and selection equipment
When choosing a refrigerator or replacing a failed unit, it is necessary to take into account many factors. Compressor performance must correspond to the volume of the chambers. For large two-chamber models over 300 liters, conventional piston models may not be energy efficient enough.
If silence is your priority, for example, the refrigerator is in the kitchen-living room or studio apartment, it is worth overpaying for inverter or linear technology. The difference in decibels will be noticeable, especially at night. At the same time, for a cottage or garage where equipment operates seasonally, overpaying for complex electronic systems may not be worth it.
It is also important to pay attention to the type of refrigerant with which the motor operates. Modern models switch to R600a (isobutane) freons, which require less substance for refilling, but are explosive. Older models ran on R134a or R12.
⚠️ Attention: Never change the compressor to a model with a different type of refrigerant without completely reworking the system. Using the wrong freon or oil will lead to blockage of the capillary tube and failure of the refrigerator.
Diagnostics of faults and signs of wear
You can understand what refrigerator compressor requires attention based on several signs. The most obvious is that the device buzzes but does not start, or turns on for a couple of seconds and clicks, followed by a pause. This often indicates problems with the starting relay or inter-turn short circuit of the windings.
If the motor runs continuously without turning off, and the chambers are not cold enough, this may indicate a loss of performance. The piston group could be worn out, and the compressor simply does not “pump” the required pressure, driving freon in a circle without a cooling effect.
Excessive heating of the compressor housing is another alarming symptom. Although normally it should be hot (up to 70-90 degrees), a temperature at which it is impossible to hold your hand indicates an overload, problems with ventilation or a freon leak.
☑️ Diagnosis of problems with the compressor
Features of replacement and maintenance
Replacing a compressor is a complex technological process that requires special equipment. It is necessary not only to dismantle the old unit, but also to thoroughly flush the system with nitrogen to remove combustion products of oil and moisture. Residual moisture is the main enemy of a new compressor.
When installing a new unit, it is critical to observe the amount of oil charged and the type of freon. Synthetic oils (POE) used with modern freons are hygroscopic and quickly absorb moisture from the air, so vacuuming should last at least 30-40 minutes.
After starting, it is necessary to check the current consumption and discharge temperature. If the parameters are normal, the system is finally sealed. It is almost impossible to do this work efficiently without a pressure gauge station and a vacuum pump.
⚠️ Attention: Refrigerator parts may vary depending on the year of manufacture and the specific modification of the model. Before ordering spare parts, always check the article number on the nameplate of your device or consult with an official service center.
Frequently asked questions (FAQ)
Is it possible to replace a conventional compressor with an inverter one?
Technically this is possible, but requires a complete replacement of the electronic control board and reconfiguration of the system. Simply installing an inverter motor instead of a conventional one without the appropriate electronics will not lead to the operation of the refrigerator, since the methods of controlling them are fundamentally different.
Why does the compressor get very hot?
Heating to 80-90 degrees is the norm for a working compressor. If the temperature is higher, the reasons may be contamination of the condenser (grid at the back), a malfunction of the thermostat, a freon leak, or a defect in the motor itself.
How long does a compressor last on average?
The average service life of piston compressors is 10-12 years. Inverter and linear models, under favorable operating conditions, can operate for 15-20 years or more. The resource depends on the quality of the voltage in the network and ventilation conditions.
What does the NL10FT marking on the compressor mean?
This is the designation of the model, where letters and numbers indicate the manufacturer (for example, Danfoss/Secop), type of refrigerant, cylinder volume and starting torque. Deciphering requires referring to the technical catalog of a specific brand.