Brand freezers Biryusa have earned a reputation as reliable “workhorses” due to their simplicity and ability to preserve food even in conditions of unstable network voltage. Understanding exactly how this unit functions allows owners not only to treat equipment more carefully, but also to diagnose faults faster, saving on calling a technician. Unlike conventional vertical cabinets, chests have horizontal loading, which radically changes the physical circulation of air inside the chamber.
The basis of the work is a closed cycle of compression and expansion of the refrigerant, which removes heat from the internal space and dissipates it into the environment. Compressor, located in the lower part of the body, acts as the heart of the entire system, creating the necessary pressure for the movement of freon. It is on its serviceability and correct operation of the thermostat that the stability of the temperature regime, critical for long-term storage of meat, fish and semi-finished products, depends.
It is important to note that the design of chests Biryusa often lacks complex electronic control boards characteristic of modern NoFrost systems, which makes them repairable in at home. However, the absence of complex electronics does not mean primitiveness: strict laws of thermodynamics apply here, the violation of which leads to breakdowns. The key feature of chests is the absence of forced ventilation, so cold air, being heavier than warm air, does not “flow” out when the lid is opened, but remains inside.
Main components of the refrigeration system
The heart of any freezer, including models Biryusa 168 or Biryusa 355, is the compressor-condensing unit. Most modern models use hermetically sealed piston compressors, which create a pressure difference, forcing the refrigerant to circulate through the tubes. During operation, the piston compresses gaseous freon, increasing its temperature and pressure, after which the hot gas is sent to the condenser.
Condenser in chests Biryusa most often made in the form of a steel sheet contour built directly into the walls of the housing, or in the form of a coil with ribs located on the outer rear wall. Heat transfer occurs continuously: passing through thin tubes, the refrigerant cools and passes from a gaseous state to a liquid state, giving off the accumulated heat to the air in the room. The efficiency of this process directly affects the energy consumption of the device.
Next, the liquid refrigerant passes through a filter-drier, which removes residual moisture, preventing the formation of ice plugs in narrow channels. After the filter, the flow enters the capillary tube - a long and very thin copper pipe that serves as a choke, sharply reducing the pressure before entering the evaporator. This is where the miracle of refrigeration occurs.
- 🔧 Compressor - creates pressure and circulation of the refrigerant in the system.
- ❄️ Evaporator - aluminum box or tubes encircling the chamber where freon boils and takes away heat.
- 💧 Filter drier —a copper cylinder that removes moisture from the circuit.
- 🌡️ Thermoregulator —a mechanical relay that opens the circuit when the set temperature is reached.
It is worth considering that the design may vary slightly depending on the year of manufacture and the specific series. If you are planning a deep repair, always check the technical documentation specifically for your model, since manufacturers can change component suppliers.
The cooling cycle and the physics of the process
The cooling process in chests Biryusa is based on the physical property of liquids to boil at low temperatures if the pressure is sharply reduced. After passing through the capillary tube, the pressure drops and liquid freon enters the expansion part of the system - evaporator. Here it begins to intensively boil, turning into steam and actively absorbing the thermal energy of the chamber walls.
In chests with an aluminum box, the evaporator is a solid container into which products are inserted. In models with a tubular evaporator (Biryusa 290, 350), copper or aluminum tubes encircle the internal volume. Heat transfer in such systems it happens more slowly than in cabinets with a fan, but the products are less aired. The refrigerant vapor is again absorbed by the compressor, and the cycle repeats.
An important aspect is the operation of the thermostat. When the temperature inside the chest drops to the set value (for example, -18°C), the sensitive capillary tube of the thermostat contracts, opening the contacts and turning off the compressor. At this point the temperature begins to rise slowly. As soon as it reaches the upper threshold (for example, -14°C), the contacts close and the motor-compressor starts again.
Why does the chest keep the cold longer?
The secret is in physics: cold air is heavier than warm air. In vertical refrigerators, when the door is opened, the cold “flows” onto the floor, being replaced by warm. In a chest, when the lid is opened, cold air remains inside, like water in a glass, which saves compressor energy.
Types of refrigerants in the Biryusa technique
For decades, the manufacturer has used various types of working substances. Older models produced before the mid-2000s were often filled with freon R12. This refrigerant had high performance, but was banned from mass production due to its negative impact on the ozone layer. Modern lari Biryusa are switching to more environmentally friendly analogues.
Today the de facto standard for household refrigeration equipment is R134a (tetrafluoroethane) or R600a (isobutane). R134a requires synthetic oil and higher system pressure, and is non-toxic and non-flammable. R600a, on the contrary, is a hydrocarbon, it has excellent cooling performance and requires less substance for charging, but is explosive when concentrated in air.
When carrying out diagnostics, it is important to know the type of refrigerant, as this affects the choice of equipment for repair. Refilling R600a requires special care and the absence of open flame sources, while R134a is more (tolerant) to the conditions of work, although it requires high-quality evacuation of the system.
| Refrigerant type | Chemical formula | Danger | Application in Biryusa |
|---|---|---|---|
| R12 | CF2Cl2 | Toxic when burned | Old models (before 2005) |
| R134a | CH2FCF3 | Safe | Medium power models |
| R600a | C4H10 | Explosive | Modern energy-efficient chests |
| R407C | Mixture | Safe | Rarely, in industrial series |
Control system and thermoregulation
Temperature control in most chests Biryusa is implemented through a mechanical thermostat (thermostat). This device is a relay that responds to changes in pressure inside a sensitive capillary tube attached to the evaporator. The user sets the rotation mode of the knob with numbers from 1 to 7 or Min/Max.
The numbers on the controller do not indicate degrees Celsius, they indicate the degree of cooling. Position “1” corresponds to the lowest temperature (the compressor turns off earlier), and “7” to maximum freezing. Electronic control It is less common, usually in top models with a display, where the accuracy of maintaining the temperature is higher, and the functionality is expanded with the “Super Freeze” or “Vacation” modes.
It is important to understand that a mechanical thermostat has hysteresis - the temperature difference between turning on and off. It can be 3-5 degrees. This is normal for this type of equipment. If the Biryusa chest works constantly or does not turn on at all, the problem most often lies in the sticking of the thermostat contacts or a freon leak, which is why the pressure in the system does not reach the response threshold.
⚠️ Attention: Never set the thermostat knob to maximum (7 or Max) unless necessary. This forces the compressor to work at its limit, which can lead to freezing of products to the evaporator and shortening the life of the motor.
Design features of the evaporator
The internal chamber of the chest is, in fact, the evaporator, or it is built into its walls. Classic models Biryusa use an aluminum evaporator box. This is a monolithic container that freezes entirely when turned on. The advantage of this design is a high freezing rate and high cold-accumulating capacity (the substance retains cold for a long time when the lights are turned off).
An alternative option is a tubular evaporator located around the perimeter of the inner chamber. It takes up less usable volume, but requires more careful defrosting. Aluminiumthe material from which these elements are made is very soft and susceptible to corrosion when in contact with acids or salts. Mechanical damage (puncture with a knife when breaking off ice) leads to instant depressurization of the circuit.
A snow coat inevitably forms on the surface of the evaporator. Unlike NoFrost systems, moisture is not removed automatically. Ice acts as an additional heat insulator, interfering with effective heat exchange between products and cold walls. Therefore, regular defrosting is a prerequisite for proper operation.
- 🧊 Aluminum box —high efficiency, but the risk of damage during defrosting.
- 🐍 Tubular coil —more space, but more difficult to clean between pipes.
- 🛡️ Coating —a food-grade anti-corrosion coating is often applied that cannot be scratched.
Diagnostics of common faults
Understanding the operating principle helps to quickly identify the cause of the failure. If the chest Biryusa hums but does not freeze, most likely there is a freon leak or the capillary tube is clogged. The compressor in this case runs empty, trying to create pressure in an empty system. To the touch, the condenser (back wall) will be cold or at room temperature, although the motor is hot.
If the unit turns on, works for several minutes and turns off with a characteristic click, and then is silent for 10-15 minutes, the problem may be in the starting relay or the compressor itself (interturn short circuit). Relay is a small plastic block placed on the compressor terminal, which is responsible for starting the engine. Replacing it is one of the most frequent and simplest repair operations.
The situation when the chest freezes too much and does not turn off indicates “sticking” of the thermostat contacts or loss of sensitivity of its capillary. In this case, the temperature inside can drop to -30°C and below, which leads to excessive energy consumption and cracking of food packaging.
☑️ Primary diagnosis of the chest
⚠️ Attention: If you smell burnt wiring or see sparking in the compressor area, immediately unplug the device. Further operation may lead to a fire.
Operation rules to extend service life
In order for the chest refrigerator Biryusa to serve for decades, it is important to follow the loading mode. It is not recommended to fill the chamber with more than 3-4 kg of warm food at a time. A sharp increase in temperature inside the chamber will force the compressor to operate in overload mode for a long time, which is critical for the motor windings.
Regular defrosting is another key factor. A layer of ice more than 5 mm thick reduces the efficiency of heat transfer by 15-20%. The chest should be defrosted at least twice a year, completely disconnecting it from the network and leaving it open until the ice has completely melted. Using a hair dryer or knife to speed up the process is strictly prohibited.
It is also necessary to ensure the cleanliness of the capacitor. If an open coil with fins is installed at the back of the chest, it must be vacuumed periodically (every six months) or carefully cleaned with a brush. Dust and animal hair, settling on the fins, act as a heat insulator, preventing the freon from cooling, which leads to an increase in pressure in the system and increased wear of the compressor.
During long periods of inactivity (for example, at the dacha in winter), it is better to store the chest in a switched off state, but with the lid open, to avoid the appearance of mold and a musty smell inside the chamber. Before turning it on again after storage in the cold, the device must be allowed to stand in a warm room for at least 4-6 hours, so that the oil in the compressor warms up and the glass in the crankcase warms up.
⚠️ Attention: Technical characteristics and design features may vary depending on the modification. Always check the parameters of your model in the official user manual or on the device nameplate before starting servicing.
Frequently asked questions (FAQ)
Why does the Biryusa chest make a loud click when turned off?
The click when turning off is the sound of the contacts of the thermostat or start relay opening. This is normal mechanical work. However, if the clicks are very frequent (every few minutes), this may indicate a malfunction of the thermostat or overheating of the compressor.
Is it possible to transport a chest freezer lying down?
Transporting lying down is undesirable, since oil from the compressor may leak into the refrigerant circuit. If transportation in a vertical position cannot be avoided, after delivery, allow the device to stand vertically without turning it on for at least 12-24 hours so that the oil flows back into the compressor crankcase.
What to do if the lid of the chest does not retain heat?
Check the integrity of the rubber seal around the perimeter of the lid. If it is dirty, wipe it with soapy water. If the seal is deformed or torn, it must be replaced, otherwise the compressor will work without interruption, trying to compensate for the heat flow.
What temperature can the Biryusa chest withstand during a power outage?
Thanks to thick walls and horizontal loading, high-quality chests Biryusa are able to keep the temperature lower -9°C (critical point for many products) from 20 to 40 hours with a full load and the lid closed, depending on the ambient temperature.