The situation when the refrigerator turns off the onset of cold weather often baffles owners of dachas and unheated warehouses. Instead of the usual hum of the engine, there is silence, and the food begins to deteriorate, although the ambient temperature seems to be helping and not hindering the operation of the unit. This paradoxical phenomenon has a clear physical explanation associated with the characteristics of the refrigerants and the operation of the control system.
Low ambient temperatures radically change the operating conditions refrigeration circuit. While the unit struggles with the heat in the summer, it experiences the opposite effect in the winter when natural cooling exceeds the thermostat's ability to regulate cycles. Understanding these processes is necessary to prevent breakdown of expensive equipment.
In this article we will analyze the technical reasons for stopping compressor in the cold, consider the influence of the type of thermostat and give practical advice on operating equipment in unheated rooms. You will find out why the minimum compressor start-up temperature is about +10°C, and what happens if you ignore this limit.
Physics of the process: the effect of cold on the refrigerant
The main reason why the refrigerator stops turning on at low temperatures lies in the properties of freon. The refrigerant circulating in the system is a gas that, under pressure, turns into a liquid, giving off heat. Freon vapor pressure directly depends on the ambient temperature. When the room becomes cold, the pressure in the evaporator and condenser drops to critical values.
The compressor is designed to work with a certain suction pressure. If the pressure drops too low due to cold, motor-compressor simply cannot start or stops immediately due to protection. The electric motor tries to start working, but it does not have enough force to pump the rarefied gas, which leads to an overload of the windings.
In addition, the viscosity of the compressor oil increases at low temperatures. It becomes thick, like tar, and cannot properly lubricate the rubbing parts in the first seconds of startup. This creates additional mechanical resistance, which often blocks the start of the unit unit.
⚠️ Attention: Prolonged attempts to start the compressor at low pressure can lead to burnout of the starting relay or motor windings. Do not leave equipment turned on in an unheated room without supervision.
The role of the thermostat in low temperature conditions
The key element that determines whether refrigerator will work in the cold is the thermostat (thermostat). This device is responsible for turning the compressor on and off depending on the temperature inside the chamber. Most household models are equipped with thermostats that are calibrated to operate in the temperature range from +10°C to +43°C.
The principle of operation is simple: the thermostat measures the temperature in the evaporator or chamber air. If it is higher than the set value, it closes the circuit, starting the compressor. However, if the air temperature in the room drops below the thermostat threshold (usually +10...+12°C), the sensor “thinks” that the room is already cold enough. It simply does not give a command to turn on, and refrigeration unit is silent.
In models with mechanical control you can often find thermostats with one contact. They break the chain when the desired cold is reached. In winter, when the environment is colder than required for storing food, this contact simply does not close. More complex electronic control systems may behave differently, but they also have restrictions on the minimum ambient temperature.
- 🌡️ Mechanical thermostats stop supplying voltage to the compressor if the room temperature is below their sensitivity threshold.
- ⚡ Electronic modules may go into error or standby mode, recording abnormally low sensor readings.
- ❄️ The temperature difference between the chamber and the street is minimal, so heat inflows are not enough to quickly heat the evaporator.
Problems with oil and the No Frost system
Refrigerators with the system No Frostare a special risk group. Such models use a complex system of air ducts and fans. When working in cold weather, the plastic from which the internal elements and dampers are made becomes brittle. Sudden temperature changes with rare starts can lead to cracks in the structure.
But the main problem lies in the oil. Compressor oil must be liquid in order to return to the compressor crankcase along with freon. In the cold, the oil thickens and can solidify in the evaporator heat exchanger. If you start compressor in such conditions, it will work without lubrication, which will lead to rapid wear of the piston group or jamming.
It is also worth considering condensate. Moisture in the air can freeze when it comes into contact with cold parts of electrical equipment, causing short circuits or corrosion of contacts. This is especially true for refrigerators with a drip systemwhere moisture is actively involved in the defrosting process.
⚠️ Attention: Do not try to heat the compressor or tubes with a hair dryer to start. Sudden heating can damage the varnish insulation of the windings or deform the gaskets.
Comparison of types of refrigerators and their resistance to cold
Not all refrigerators react equally to cold. There are models specially designed to work in a wide climatic range, and there are those that absolutely cannot be used at low temperatures. It is important to distinguish between the climate classes indicated in the technical data sheet of the device.
Most household models belong to class SN (subnormal) or N (normal), which means operation at ambient temperatures from +10°C to +32°C (or +38°C). If the temperature drops below +10°C, the manufacturer voids the warranty. However, some industrial or specialized models can operate at lower temperatures.
Below is a table showing the dependence of the operation of various components on temperature:
| Component | Temperature +20°C | Temperature +5°C | Temperature -5°C |
|---|---|---|---|
| Freon pressure | Normal | Reduced | Critical low |
| Oil viscosity | Optimal | Increased | Thickened/Hard |
| Thermostat | Working normally | May not turn on | Won't turn on |
| Plastic No Frost | Elastic | Hard | Fragile |
Can a refrigerator be used as a cabinet?
Yes, you can. If you unplug the refrigerator and leave it in the cold, it will operate like a regular cabinet. The main thing is to keep the doors open or provide ventilation so that mold does not grow inside.
What happens to single-compressor and two-compressor models
The difference in the behavior of single-compressor and double-compressor models in the cold is significant. B single-compressor refrigerators one motor serves both cameras. The thermostat is usually located in the refrigerator compartment. If it is cold there (due to low room temperature), the motor will not start and the freezer will also stop freezing. The food in the freezer will begin to defrost, even if it is frosty outside.
In two-compressor models the situation can develop according to two scenarios. If the freezer's thermostat is independent, it can continue to run until it gets too cold. However, the refrigerator compartment will most likely shut down first. The problem is that defrost cycles (in No Frost models) may not start, since the defrost sensor does not detect the heat required to start the evaporator defrost cycle.
This leads to fouling of the evaporator with a “coat” of ice. When you bring such a refrigerator into a warm place, it may not work immediately, since the ice plug will block the circulation of the refrigerant. Defrosting system in such conditions it becomes useless.
- 🔌 Single-compressor models are completely dependent on the temperature in the refrigerator compartment, which the cold does not rise.
- 🧊 Two-compressor models can partially function, but the risk of disrupting the defrost cycle is very high.
- 🛑 Electronic control in both cases can produce temperature sensor errors.
Practical tips for operation in an unheated room
If you have no choice and refrigerator you have to work in the country or in the garage in the winter, you need to take a number of measures. First, try to minimize temperature changes. The room must be at least minimally insulated. Secondly, monitor the humidity - it should not be high to avoid corrosion and short circuits.
Some experts recommend replacing the standard thermostat with a model with a lower switching threshold or using external thermostats, but this requires deep knowledge and voids the warranty. A safer way is to install a heater in the room that will maintain the temperature above +10°C.
It is also worth (regularly checking) the condition of the seals. In the cold, the rubber hardens and stops fitting tightly, releasing heat (if the refrigerator is running) or letting in moisture. Rubber seals can be lubricated with silicone grease to maintain elasticity.
☑️ Check before turning on for frost
Frequently asked questions (FAQ)
Is it possible to turn on the refrigerator immediately after it has been brought in from the cold?
Absolutely not. The refrigerator needs to warm up to room temperature while turned off within 3-4 hours. Turning on a cold compressor with thickened oil will lead to its breakdown.
Why does the refrigerator click but does not start in the cold?
The click means an attempt to start the start relay. If the compressor does not start, it means that the freon pressure is too low to start, or the oil has frozen and is blocking the pistons. The relay opens the circuit to protect the motor from combustion.
Are there refrigerators designed to operate in cold weather?
Yes, there are models with climate class T (tropical) or ST (subtropical), which have an extended range, but even they are rarely designed to operate at subzero temperatures. There are special low-temperature models for chest freezers.
How to preserve a refrigerator for the winter?
Unplug the appliance, defrost, wash thoroughly and wipe dry. Leave the doors ajar (you can insert a rag or cardboard) to ensure air circulation and avoid mold.