Modern DEXP refrigerator is a complex thermodynamic system designed to maintain a low temperature inside the chambers to preserve products. Despite the variety of models, whether compact DEXP RC-50 or spacious two-chamber DEXP RC-320, the basic physical principle of their operation has remained unchanged for many decades. It is based on a continuous cycle of compression, condensation and evaporation of the refrigerant.
Understanding how exactly refrigeration unit removes heat from the internal volume to the outside helps owners better operate the equipment and avoid common mistakes. Many users mistakenly believe that cold is “created” inside, when in fact the device is only actively pumping out thermal energy. This process requires constant energy consumption and the serviceability of all components.
In this article we will analyze in detail each stage of the work of the climate equipment Dexp brand, consider the role of the compressor, features of the defrosting system and the nuances of air circulation. Knowledge of the internal structure will allow you to quickly diagnose malfunctions and extend the life of the equipment.
Fundamentals of thermodynamics: how cold is created
The fundamental element that provides cooling is refrigerant (often called freon). DEXP refrigerators use modern ozone-friendly gases such as R600a. This substance has the unique ability to change its temperature with changes in pressure. The cycle begins with the gaseous refrigerant entering the compressor.
Here it is compressed, as a result of which the temperature of the gas increases sharply, and it goes into a state of high pressure. Moving through the condenser tubes, usually located on the back wall or hidden in the side panels, the hot gas gives off heat to the environment. The critical point is that when cooled to room temperature, the refrigerant condenses and becomes a liquid, while maintaining a high pressure.
The liquid then passes through a capillary tube or throttle, where the pressure drops sharply. Once in the evaporator, the refrigerant boils at very low temperatures, actively absorbing heat from the internal volume of the chambers. It is this process that we feel as “cold.”
⚠️ Attention: If you notice that the back wall of the refrigerator is heating up more than usual, this may indicate a dirty condenser or problems with ventilation. Do not ignore this signal, as overheating of the compressor can lead to its failure.
The efficiency of heat transfer directly depends on the cleanliness of the external elements of the system. Dust settling on the radiator grille creates an insulating layer that prevents the transfer of heat to the atmosphere. In models DEXP with a bottom-mounted compressor, it is important to regularly check the space behind the baseboard or in the installation niche.
The heart of the system: the design and operation of the compressor
The compressor in the DEXP refrigerator performs the function of a pump that forces the refrigerant to circulate in a closed circuit. This electromechanical device creates the pressure difference necessary for phase transitions of the working fluid. Modern models can use both classic inverter and standard piston motors.
When a thermostat or electronic sensor detects an increase in the temperature inside the chamber above a set value, it sends a signal to start the engine. The compressor begins to work, pumping up pressure in the condensation system. Performance the entire cooling system depends on the tightness and power of this unit.
It is important to understand that the compressor does not run idle. Its task is to pump a certain amount of refrigerant. If a freon leak occurs in the system, the motor will work continuously, trying to reach the set temperature, which will inevitably lead to its overheating and breakdown.
Modern motor-compressors equipped with protective relays that turn off the power in case of critical overheating or power surges. This prevents the windings from catching fire. However, frequent activation of the protective mechanism indicates a malfunction in the cooling system or electrical system.
Differences in cooling systems: static versus No Frost
DEXP refrigerators, like other equipment, are divided into models with a drip defrosting system (Direct Cool) and system No Frost. In models with a drip system (often in single-chamber or budget double-chamber versions), the evaporator is located directly on the rear wall of the refrigerator compartment.
Moisture from the air condenses on the cold wall, turning into frost. Periodically, the compressor turns off, the wall heats up, and the frost melts, flowing into a special groove and then into the evaporator for disposal. In the freezer compartment of such models, defrosting is usually carried out manually.
The system No Frost (or Full No Frost) works on a different principle. Here the evaporator is hidden and located in a separate compartment, often at the top of the freezer or between the compartments. Cooling of products occurs not from contact with the walls, but due to forced circulation of cold air.
- ❄️ The fan forces cold air from the evaporator into the chambers through special channels.
- 🌬️ The air is evenly distributed throughout the entire volume, ensuring the same temperature on all shelves.
- 🔄 The heating element (heating element) is periodically turned on, which thaws the evaporator, and the water is removed by gravity.
The advantage of the system No Frost is the absence of the need for manual defrosting and a more stable temperature regime. However, it is worth considering that air circulation can lead to faster drying of products if they are not packaged.
Why does ice sometimes appear in No Frost?
In the No Frost system, ice can form if the defrost sensor is faulty or the drain hole is clogged. The water from the melting frost does not have time to leave and freezes, forming snowdrifts that can block the operation of the fan.
Air circulation and temperature distribution
For effective storage of food, it is important to understand how the air masses move inside refrigerator cabinet. In DEXP models with a multi-flow cooling system (Multi Air Flow), air is supplied through several holes at different levels. This avoids the formation of “heat pockets” where the temperature could be higher than normal.
Cold air is heavier than warm air, so it tends to sink down. That is why the temperature on the lower shelves of the refrigerator is usually lower than on the upper ones. This is a natural physical feature that should be taken into account when placing products. It is better to place products that do not require strong cooling on the top shelves.
In a freezer with a system No Frost air flows are directed so as not to blow moisture directly out of the products, but still ensure rapid freezing. The fan speed can be adjusted electronically depending on the current load and temperature.
Proper loading of the chambers is the key to long service life of the equipment. If you fill the refrigerator with food to capacity, circulation will be disrupted and the sensors may not read the temperature correctly. Always leave a small gap at the back wall for the free movement of air masses.
Control and electronics: smart control
Modern DEXP refrigerators are equipped with electronic control units that control the operation of all systems. Thermal sensorslocated at various points in the chambers, constantly transmit data to the control board. Based on these readings, a decision is made to turn on or off the compressor, fan and defrost heating element.
The user interface can vary from a simple mechanical dial to a touch panel with display. Electronics allow you to set precise temperatures in 1-degree increments, which is impossible to do with a mechanical thermostat. The defrost operating time is also monitored.
In the event of a malfunction, the electronic module can block the operation of the compressor to avoid an accident and display an error code on the display or signal it by flashing indicators. This greatly simplifies diagnostics.
In the hidden compartment of the evaporator
In the freezer compartment (No Frost)
| Component | Function | Location |
|---|---|---|
| Thermal sensor | Air temperature measurement | Inside the chambers, on the evaporator |
| Control board | Data processing and control nodes | Upper part or behind the panel |
| Defrost heating element | Heating the evaporator to remove ice | |
| Fan | Cold circulation air |
The use of a stabilizer or at least a high-quality surge filter can protect an expensive control unit from combustion.
Typical problems and their connection with the device
Knowledge of the principles of operation helps to understand the causes of breakdowns. For example, if your refrigerator is humming but not cooling, there is most likely a problem with the compressor or a refrigerant leak. If it works, but a “coat” of ice forms inside, a malfunction in the defrosting system is possible. No Frost.
The fan may produce extraneous noise if ice has frozen on its blades or an icicle has gotten from the drainage. A knock often indicates problems with the compressor mounts or the entry of foreign objects into the engine compartment.
☑️ Noise diagnostics
If you hear gurgling or hissing, this is often normal. These are the sounds of refrigerant flowing through the pipes, especially noticeable immediately after the compressor stops or when it starts. However, loud bubbling may indicate airing of the system.
⚠️ Attention: Independent repair of the cooling system (replacing the compressor, refilling with freon) requires special equipment and skills. An attempt to do this without experience can lead to complete failure of the unit and is dangerous to health.
Operating rules for extending service life
In order DEXP refrigerator to serve for a long time and reliably, you must follow a number of simple rules based on the principles of its operation. Do not place hot food inside - this puts excess load on the compressor and disrupts the temperature regime. Let the food cool to room temperature.
Check the door seals regularly. If the elastic does not fit tightly, warm, moist air enters. This leads to increased frost formation on the evaporator and more frequent motor cycles. Wipe the seals with a soft, damp cloth.
Do not install the refrigerator near heat sources (stoves, radiators) or in direct sunlight. The efficiency of heat transfer by the condenser in such conditions decreases, and the equipment wears out. It is also necessary to provide clearances for ventilation specified in the instructions.
Frequently asked questions (FAQ)
Why does the DEXP refrigerator make clicking noises when work?
Clicks are most often produced by the thermal relay, which controls the start and stop of the compressor. This is normal operating sound. Also, plastic parts of the case can make clicking noises during thermal expansion (contraction) during cooling and defrosting cycles.
How often do you need to defrost a refrigerator with the No Frost system?
The No Frost system does not require manual defrosting to remove ice, as this happens automatically. However, 1-2 times a year it is recommended to turn off the refrigerator for general cleaning, washing the internal surfaces and drying them to remove odors and bacteria.
What does a flashing temperature indicator mean?
A flashing indicator usually indicates that the temperature inside the chamber is higher than the established norm. This may occur after initial switching on, after a long defrosting period, or after loading a large amount of warm food. If the blinking does not stop after a few hours, the sensor may be faulty or there is a freon leak.
Is it possible to transport a DEXP refrigerator lying down?
Manufacturers do not recommend transporting refrigerators lying down, as oil from the compressor may leak into the refrigerant circuit. If transportation in a horizontal position is unavoidable, after installing it vertically, you must wait at least 4-6 hours (preferably a day) before turning it on, so that the oil flows back into the compressor.