The situation when household appliances fail at the most inopportune moment always causes stress, but it especially surprises users when the refrigerator stops working in the cold. It would seem that logic dictates that if it’s already cold outside, then the unit has nothing to fear, because its task is to cool. However, practice shows the opposite: taking the device to an unheated balcony or garage in winter often leads to breakdowns.
Violation of the operating temperature conditions is one of the most common causes of failure compressor-condensing units. Manufacturers clearly indicate the climate class in the instructions, ignoring which leads to expensive repairs. In this article, we will analyze in detail the physical and chemical processes occurring inside the system at low temperatures, and explain why technological progress has not yet defeated the laws of thermodynamics.
Understanding the operating principles of refrigerant and lubricants will help you avoid fatal mistakes. We will consider not only theoretical aspects, but also the practical consequences faced by equipment owners who decide to save on installation or simply do not know the basic rules of operation.
Physics of the process: why cold harms refrigeration
The main reason for equipment failure lies in the principle of operation refrigerant. In normal mode, a gaseous substance, passing through a compressor, is compressed and heated, after which it enters the condenser, where it cools and turns into liquid. It is this cycle that ensures the extraction of heat from the inner chamber. When the ambient temperature drops below zero, heat transfer is radically disrupted.
At extremely low temperatures, the refrigerant simply does not have time to boil in the evaporator or, conversely, does not condense properly in the radiator. Thermodynamic cycle breaks: the gas does not transform into the required phase states in the right time. As a result, the compressor may run idle or, worse, experience overload, trying to pump through the thickened mixture.
⚠️ Attention: If you notice that the refrigerator is humming, but is not cooling at temperatures below +5°C, immediately unplug it. Further operation under such conditions will lead to a wedge of the compressor.
In addition, it is worth taking into account the operation No Frost systemsif it is provided for by the model. Humidity and temperature sensors in such devices are configured to a certain range. In severe frost, the electronics may receive false signals that the chamber is already quite cold and turn off the compressor, although the food inside has already defrosted due to the air circulation stopping.
Problems with compressor oil and lubricant
The heart of any refrigerator is compressor, inside of which there is a special compressor oil. It is necessary to lubricate the rubbing parts of the piston group and ensure the tightness of the gaps. This oil has a strictly defined viscosity range, depending on the ambient temperature.
When the temperature drops below the permissible minimum (usually +5...+10°C), the oil begins to thicken. The viscosity increases many times over, and it becomes physically difficult for the pump to pump it through the system. This leads to two main problems: insufficient lubrication of moving parts at the time of start-up and increased load on the electric motor.
- 🛑 Oil wedge: Thick oil blocks the movement of the pistons, the compressor hums, but cannot start.
- 🛑 Winding combustion: Trying to overcome the resistance of the thick lubricant, the motor consumes current higher than nominal and burns out.
- 🛑 Oil failure: Oil does not have time to return from the system to the compressor crankcase, which leads to dry operation.
The situation is especially critical for older models where they are used mineral oils. Modern synthetic lubricants inverter compressors are a little more resistant to changes, but they are not designed to work in Russian winter conditions on an open balcony.
The influence of humidity and the formation of ice jams
Another hidden the enemy is moisture. The air always contains a certain amount of water vapor. When the refrigerator operates in the cold, this steam can penetrate into the technical compartments or even into the circuit through microcracks in the seals. At subzero temperatures, moisture crystallizes.
The formation of ice in the system capillary tubes or in the throttle area (thermostatic valve) creates a so-called “ice plug”. This physically blocks the path to the refrigerant. The circulation of freon stops and the refrigerator ceases to perform its function, although the compressor can continue to work.
How does moisture get inside the system?
Moisture can penetrate through leaks during transportation if the refrigerator was lying on its side, or through microscopic damage to the pipes. Condensation also forms inside during a sharp temperature change when a warm unit is taken out into the cold.
In addition, condensation that forms on electronic control boards when a warm device is brought into a cold room can cause a short circuit. Electronic components they are extremely sensitive to humidity and icing of contacts. Even if the refrigeration circuit itself survives, the control unit may fail instantly.
Failures in the thermostat and automation
The thermostat (thermostat) is a device that commands the compressor to turn on or off depending on the temperature inside the chamber. In severe frost, the logic of operation of this element is disrupted. If the refrigerator is in a room where the air temperature is equal to or lower than that set in the chamber, the thermostat may simply “not understand” that it needs to be cooled.
In mechanical thermostats with a bellows tube, at low temperatures, the pressure of the filler gas drops. As a result, the contacts may not close and the compressor will not start at all. Or, on the contrary, it will work continuously, trying to reach the unattainable -20°C, since the sensor will show that the chamber is “warm” relative to the outside frost.
In models with electronic control temperature sensors (NTC thermistors) also have errors when they go beyond the operating range. The controller’s operation algorithm may be disrupted: upon receiving data that “it’s cold around,” the system may go into standby mode or make an error.
Comparison of climate classes of equipment
Not all refrigerators react equally to cold. Manufacturers mark equipment according to climate classes, which determine the permissible range of ambient temperatures. Ignoring this marking is the main mistake of users.
| Climate class | Temperature range (°C) | Where it can be used | Reaction to frost |
|---|---|---|---|
| N (Normal) | +16 ... +32 | Heated apartments | Failure below +10 |
| SN (Subnormal) | +10 ... +32 | Cool corridors | Failure below +5 |
| ST (Subtropical) | +18 ... +38 | Hot climate | Not suitable for cold |
| T (Tropical) | +18 ... +43 | Tropics, deserts | Critical to cold |
| Note: Most household models in the Russian Federation belong to classes N and SN. | |||
As can be seen from the table, the lower limit even for the most “cold-resistant” household class SN is +10°C. Dropping the temperature below this threshold takes the equipment out of the zone of guaranteed performance. Climate class This is not just a formality, but an engineering calculation of thermal loads.
What to do if the refrigerator is already in the cold?
If the situation has already occurred and the refrigerator is in the cold, you need to act wisely to minimize the damage. The first rule: do not try to immediately turn on the device if it has been in the cold for a long time.
It is necessary to give the equipment time to acclimatize. Bring the refrigerator into a warm room and do not turn it on for at least 24 hours (preferably more). This is necessary so that the oil in the compressor warms up and regains its fluidity, and the condensate on the contacts completely evaporates.
☑️ Algorithm of actions after cold
After turning on, listen carefully to the operation of the motor. If you hear a hum but don't start, or if the engine runs continuously without cooling, these are signs of a serious problem. In such cases, you need to call a technician to diagnose start-protection relay and check the pressure in the system.
Frequently asked questions (FAQ)
Is it possible to keep a refrigerator on a glazed balcony in winter?
Only if the balcony is insulated and the temperature there does not drop below +5°C. On an unprotected balcony in winter, the temperature often drops to -10°C or lower, which is strictly prohibited for the operation of the compressor and electronics.
Why does the refrigerator click but does not turn on after frost?
Most likely, the start-up relay has tripped. The oil in the compressor has frozen, the piston cannot budge, the current increases, and the relay breaks the circuit, making a click. The compressor needs to be warmed up or the starting device needs to be replaced.
Are there refrigerators that operate at -20°C?
There are practically no household models that can operate stably at -20°C. There are industrial chest freezers, but regular home refrigerators are not designed for this. For a garage, it is better to use specialized equipment.
Is condensation inside the refrigerator dangerous after it has been brought in from the cold?
Yes, very much so. Moisture can cause corrosion of metal parts, a short circuit in the control unit and the formation of ice plugs in the refrigerant circulation system. Therefore, drying is mandatory.
Is it possible to use a refrigerator in the cold only as a freezer?
No, this is a misconception. Even if you only need the freezer, the compressor and oil work throughout the entire system. The operating conditions for the compressor remain the same critical, regardless of which chamber you use.