Understanding exactly how your cooling equipment functions is the foundation for its long and trouble-free operation. Polair refrigerators, despite the diversity of the model range, they are based on time-tested physical laws of thermodynamics, implemented through a complex system of mechanical and electronic components. Knowledge of the basic principles allows the owner not only to correctly set up storage modes, but also to quickly respond to the first signs of a malfunction, preventing expensive repairs.
The process is based on the continuous circulation of the refrigerant, which, changing its state of aggregation, transfers thermal energy from the internal chamber to the outside. This is not magic, but a clear sequence of compression, condensation, expansion and evaporation, which is controlled by an electronic control board. Modern Polair models equipped with inverter motors and a multi-flow cooling system, which makes their operation quieter and more energy efficient compared to their classic counterparts.
Consideration The device should start from the very heart of the system - the compressor unit. It is this that creates the necessary pressure for the movement of freon in a closed circuit. Unlike old models, where the motor worked in start-stop mode, modern units can smoothly regulate power, maintaining the set temperature with a minimum error.
The basis of the cycle: compressor and refrigerant
The compressor in refrigerators Polair acts as a pump that sucks in gaseous low pressure and temperature refrigerant from the evaporator. After compression, the gas is heated and sent under high pressure to the condenser. The reliability of this unit is critically important, since it is it that consumes the bulk of the electricity.
Environmentally friendly freon R600a (isobutane) is most often used as a working fluid. It has excellent thermodynamic properties and low viscosity, which allows the use of lower power compressors. However, due to the flammability of this gas filling the system requires special care and compliance with fire safety measures, which makes independent repair of the circuit extremely risky.
The compression process is accompanied by a significant release of heat, so the compressor housing is always hot in operation. The refrigerator electronics strictly monitor the temperature of the motor windings, and if overheated, they can forcibly turn off the unit to prevent combustion.
Circulation of the refrigerant is impossible without the tightness of the system. Even a microscopic leak leads to a drop in pressure and loss of cooling capacity. Therefore, all connections in the circuit are made by brazing and not mechanical fittings.
Heat exchange: condenser and capillary tube
After leaving the compressor, the hot gas enters the condenser. In refrigerators Polair this unit is often made in the form of a black lattice panel on the back wall or hidden in the side walls of the case (built-in models). Here, heat is released into the environment.
Passing along a long coil, freon cools down and turns into a liquid state. This process is called condensation. The efficiency of heat transfer directly depends on the cleanliness of the grille: the layer of dust acts as a heat insulator, causing the compressor to work with overload.
- 🌡️ The condenser must be hot or warm along its entire length during operation.
- 🧹 Regular cleaning of the rear grille from dust extends its service life unit.
- 🌬️ For normal operation, a gap of at least 10 cm is required between the back wall and the furniture.
Next, the liquid refrigerant passes through a filter drier, which removes residual moisture, preventing the formation of ice jams. The flow then enters a capillary tube - a very thin copper pipe that creates high hydraulic resistance. It is here that a sharp drop in pressure occurs before entering the evaporator.
Why is the capillary tube so thin?
The diameter of the capillary is a fraction of a millimeter. This is necessary to create a pressure difference, without which freon will not be able to boil at a low temperature in the evaporator.
Evaporator and No Frost system
In the evaporator, which is located inside the refrigerator or freezer, the pressure drops sharply, and liquid freon boils, turning into gas. During this process, intense heat absorption occurs from the interior of the refrigerator.
In models with a system No Frost (full or partial), one common evaporator is used, usually located in the upper part of the freezer or behind the rear panel. Cold air is forced into the air by a fan and distributed through the channels.
This scheme avoids the formation of ice on products and walls, since moisture is frozen out on a hidden evaporator. Periodically, the system goes into defrost mode, heating the heater to melt the accumulated ice.
If the fan stops or the air ducts become clogged, the cold stops flowing into the chamber, although the compressor can run continuously. In classic drip systems, moisture simply flows down the back wall, freezing and thawing during motor cycles.
Electronic control and sensors
A modern refrigerator Polair is a complex electronic device. All processes are monitored by a control module that receives data from numerous sensors. The main elements are thermal sensors that measure the air temperature in the chambers and the evaporator temperature.
The controller operation algorithm is based on comparing sensor readings with user-specified values. If the temperature in the chamber rises above the threshold, the board gives a command to turn on the compressor. In inverter models, the command sounds like “increase speed”
Logic: If Temp > SetPoint + Delta then Compressor ONThe system also controls the operation of defrosting. The defrost sensor (defroster) tells the board when the ice on the evaporator has completely melted to turn off the heating element and start the compressor again. A malfunction of this sensor often leads to freezing of the evaporator.
- 📡 The air temperature sensor regulates the frequency at which the motor turns on.
- 🔥 The defrost sensor protects the system from overheating during defrosting.
- 🚪 The door open sensor turns on the backlight and signals the module about loss cold.
Typical malfunctions and their symptoms
Knowledge of the device helps to diagnose breakdowns. For example, if the compressor hums, but does not start, and after a while it clicks, the problem is probably in the start relay or the compressor itself (jamming). If the motor runs constantly, but there is no cold, looking for a leak or loss of performance.
⚠️ Attention: If you hear gurgling or hissing after the compressor stops, this is normal. The refrigerant continues to flow in an area of equal pressure. Don’t rush to call a technician.
In models with No Frost, a common problem is the failure of the blower fan. Symptoms will be the absence of cold in the refrigeration chamber when the compressor is running and the presence of frost only near the evaporator itself. The defrost heating element may also burn out, which will lead to ice fouling and blocking of air channels.
Electronic modules are sensitive to power surges in the network. Unstable power supply can lead to “glitches” of the control board, when the refrigerator randomly turns on and off. In such cases, flashing or replacing the controller is often required.
Comparing the characteristics of cooling cycles
To understand the efficiency of various components, it is useful to compare parameters at different points in the cycle. The table below shows how the state and parameters of the refrigerant change.
| System unit | Freon state | Pressure | Temperature |
|---|---|---|---|
| At the outlet compressor | Gas (superheated) | High | High (+60..80°C) |
| After condenser | Liquid | High | Average (+30..40°C) |
| After capillary | Liquid + Gas | Low | Low (-20..-30°C) |
| At the evaporator outlet | Gas | Low | Low (-10..-20°C) |
These parameters are calculated for the standard operating mode. In reality, the values may fluctuate depending on the ambient temperature and the load of the refrigerator with food.
☑️ Diagnosis of cooling problems
Recommendations for operation and care
For stable operation of the refrigerator Polair it is important to follow the operating rules. Do not load hot products into the chambers - this will place excessive load on the compressor and lead to the formation of condensation. It is also not recommended to block the ventilation holes inside the camera.
⚠️ Attention: Specifications and location of service menus may vary depending on the specific series and year of manufacture. Always check the official documentation for your model before tampering with the electronics.
Regularly check the integrity of the door seals. If the rubber does not fit tightly, warm, moist air enters the chamber, which leads to increased ice formation and increased defrost cycles. The seals should be wiped with a soft damp cloth, avoiding aggressive chemicals.
Once a year, it is recommended to completely defrost (even for No Frost systems) and clean the drainage channels. This will help remove the smell and prevent clogging of the melt water drainage system, which can leak under the refrigerator.
How to check the tightness of the door?
Use a sheet of paper. Clamp it with a closed door around the perimeter. If the sheet is pulled out too easily without resistance, the seal requires replacement or adjustment of the hinges.
Frequently asked questions (FAQ)
Why does the Polair refrigerator make a loud click before turning on?
The click is the sound of the start relay operating, which gives an impulse to start compressor windings. If the clicks are repeated frequently and the motor does not start, the relay may be faulty or the compressor is jammed.
How often should the defrost system turn on?
Depending on the model and the humidity in the chamber, the defrost cycle in refrigerators with No Frost starts every 8-16 hours of compressor operation. This process usually lasts 15–30 minutes.
Is it possible to transport a Polair refrigerator lying down?
Manufacturers do not recommend transportation on its side, as oil from the compressor may leak into the circulation circuit, which will cause an oil plug. If transporting lying down is unavoidable, let the refrigerator stand upright for at least 4-6 hours before turning it on.
What does a flashing temperature indicator mean?
Flashing usually signals an alarm. This may be an increase in the temperature in the chamber above normal (for example, after loading products) or a sensor malfunction. If the temperature is normal and the indicator is blinking, check that the door is closed tightly.