A refrigerator is a complex mechanism that works thanks to the circulation of a special substance that absorbs heat from the chamber and releases it to the environment. Many users know this substance under the name freon, but technically it is more correct to call it a refrigerant. It is this gas that provides the very cold that allows you to keep food fresh for weeks.
The principle of operation is based on a constant change in the state of aggregation of a substance: when it evaporates, it takes energy, and when it condenses, it releases it. This process is repeated endlessly until the compressor creates the required pressure in the system. Understanding exactly how it works refrigerantwill help you better understand the causes of breakdowns and communicate more effectively with the technician during repairs.
Modern models use different types of gases, each of which has its own safety and environmentally friendly characteristics. Some of them can be dangerous if leaked, while others are practically harmless to humans, but harmful to the ozone layer. Let's figure out what exactly circulates inside the tubes of your household appliance.
The principle of operation of the cooling circuit
The entire cooling system is a closed circuit through which the working fluid continuously moves. The compressor compresses the refrigerant gas, increasing its temperature and pressure, after which the hot gas enters the condenser (usually a grille on the back wall). There it cools and turns into liquid, releasing heat into the kitchen.
The liquid refrigerant then passes through a filter drier and enters a capillary tube, where the pressure drops sharply. Once in the evaporator hidden inside the freezer, the substance boils at a very low temperature. At this moment, active absorption of heat from the internal volume of the refrigerator occurs, which creates the necessary cold.
- 🔄 Compressor creates pressure and forces the gas to move in a circle.
- 💨 In condenser the gas cools and turns into liquid.
- ❄️ In evaporator the liquid boils, taking heat from the chambers.
After the evaporator, the gaseous substance returns again, which is again sucked in by the compressor. The cycle is repeated until the temperature sensor informs the system that the desired temperature has been reached. It is important to understand that the amount of refrigerant in the system is strictly regulated by the manufacturer.
Main types of refrigerants in household appliances
The history of the development of refrigeration equipment goes back more than a hundred years, and during this time the chemical composition of working substances has changed several times. Previously, ammonia and sulfur dioxide were used, which were toxic and explosive. Later, chlorofluorocarbons appeared, which became the standard for many decades.
Modern industry switched to more environmentally friendly analogues, since old types of freon destroyed the Earth's ozone layer. Now in stores you can find models that operate on different types of gases, and not only the efficiency, but also the complexity of repairs depends on this.
⚠️ Attention: Never try to determine the type of gas by smell or color. Leakage of some invisible gases can be hazardous to health in confined spaces.
The following table is to help you understand the main types of substances used today:
| Refrigerant type | Chemical formula | Features | Environmentally friendly |
|---|---|---|---|
| R600a | Isobutane | Explosive, small quantity | High |
| R134a | Tetrafluoroethane | Safe, non-flammable | Average |
| R12 | Dichlorodifluoromethane | Outdated, toxic | Low |
| R407c | Mixture of gases | Used in large systems | Medium |
The most common in modern household refrigerators is isobutane. It is effective and cheap, but requires special care when repairing due to its flammability. The technician should not use an open flame when soldering tubes if this gas remains in the system.
Symptoms of freon shortage or leak
Since the refrigerant circulates in a sealed circuit, in a working refrigerator its quantity does not change for years. However, mechanical damage, corrosion or manufacturing defects can lead to depressurization. How to understand that the gas has left? The first sign is often a change in the operating mode of the compressor.
The unit may start working non-stop, trying to reach a temperature that it physically cannot reach due to a lack of working fluid. Or, on the contrary, turn on for short periods of time, since the temperature sensor does not have time to react to the lack of cooling capacity.
- 🌡️ The temperature in the chambers is higher than the established norm.
- 🔊 The compressor hums continuously or turns on too often.
- 💧 On the floor under the refrigerator or puddles appear on the shelves.
- 🧊 The evaporator is covered with an uneven layer of frost or ice.
If you notice that the freezer is working, but it’s warm in the main chamber, this is a sure sign of a problem with circulation or the amount of gas. A characteristic chemical odor may also appear, although modern gases often do not have a pronounced aroma.
⚠️ Attention: Independent refueling of the refrigerator is impossible without special equipment and skills. An attempt to simply “add gas” without looking for a leak will lead to a repeat breakdown in a short time.
The danger of self-repairing the system
Many owners, having seen the price of a specialist’s services, think about fixing the problem themselves. However, the cooling system is under pressure and intervention requires a professional tool. In addition, different types of gases require different oils to lubricate the compressor.
If another is pumped into a system designed for one type of freon or mixed, the compressor can fail almost instantly. It is also critically important to remove moisture from the circuit, for which a vacuum pump and special filters are used.
Why can’t you just buy a cylinder with freon?
In household stores, cylinders with refrigerant are rarely sold and often illegally. Even if you find gas, you will need a gauge station, a scale for accurate dosing, and a vacuum pump. Without removing air and moisture from the system, the new gas will mix with the remains of the old gas and air, forming aggressive acids that will destroy the compressor from the inside.
Another important aspect is fire safety. As mentioned earlier, the popular R600a is a flammable gas. If the tubes are soldered incorrectly or the contacts spark, a bang or fire may occur. This is not a theoretical danger, but a real threat to property.
Process of professional refilling
When the technician arrives on a call, he does not just connect the cylinder and fill the system. Repair begins with finding the location of the leak. To do this, a leak detector or a nitrogen pressure test method is used, which allows you to find even microscopic fistulas in the foamed part of the housing.
After eliminating the defect, soldering and installation of a new filter-drier are performed. The old filter cannot be reused, as it has already absorbed moisture and oil breakdown products. Then the system is evacuated.
- Find and eliminate leaks (replace the tube, repair the evaporator).
- Replace the filter-drier.
- Evacuate the circuit to remove air and moisture.
- Refill with a strictly calculated amount refrigerant.
Only after completing all these steps can the refrigerator operate for a long time and stably. The amount of gas is measured in grams, and a deviation of even 10-20 grams can lead to incorrect operation or increased energy consumption.
Environmental standards and the future of refrigerants
The world community pays great attention to the impact of refrigeration equipment on the climate. Protocols and agreements regularly tighten the requirements for the substances used. Manufacturers are forced to switch to new formulas that do not destroy the ozone layer and have a low global warming potential.
Active development is currently underway to use natural refrigerants, such as propane or carbon dioxide, on an industrial scale. For household refrigerators, isobutane has become the de facto standard, which, despite its flammability, is the most environmentally friendly solution at the moment.
When disposing of an old refrigerator, it is important to hand it over to special collection points. There, specialists will safely remove the remaining freon without releasing it into the atmosphere. By throwing equipment into a landfill, you contribute to the release of harmful substances into the soil and air.
⚠️ Attention: Disposal rules and regulations, as well as permitted types of gases, may vary depending on the legislation of your country. Current information can always be found on manufacturers' websites or in state environmental registers.
Frequently asked questions (FAQ)
Can the freon in the refrigerator run out on its own?
No, the refrigerant circulates in a closed, sealed circuit and is not consumed as fuel in the car. If there is less gas, it means that a crack or hole has formed somewhere through which it has escaped.
How much does it cost to refill a refrigerator with freon?
The price depends on the model, type of gas and complexity of access to the system. Usually the cost consists of the work of the master, the cost of materials (gas, filter, solder) and travel. The exact amount can be found out only after diagnosis.
Is the smell of freon dangerous for children and animals?
Modern gases (R134a, R600a) in small quantities contained in a household refrigerator are not toxic to humans. However, at high concentrations they displace oxygen, which can cause suffocation. If there is a strong smell, you need to ventilate the room.
How often do you need to change freon?
You never need to change or add freon to a working refrigerator. If the system is sealed, the gas lasts the entire service life of the appliance, which can be 10-20 years.
Why do new refrigerators have less freon?
Modern compressors and heat exchangers have become more efficient. To achieve the desired cold, a smaller amount of working substance is now required, which also increases the environmental friendliness of the equipment.