Owning professional refrigeration equipment requires an understanding of technical nuances, and one of the key issues during maintenance is the type of refrigerant used. For equipment owners and maintenance personnel Polair it is important to know exactly what kind freon is charged into the system, since cooling efficiency and operational safety depend on this. Incorrect selection of gas can lead to compressor failure or even an emergency.
Modern Polair refrigerators, depending on the year of manufacture and series, can be charged with various types of refrigerants. The most common are R134a and R600a, each of which has its own physical and chemical properties. The use of R600a (isobutane) requires special care due to its high flammability, unlike inert R134a. In this article we will examine in detail the methods for determining the type of gas, the features of each system and the nuances of maintenance.
Ignoring factory specifications when refueling or repairing is a direct path to expensive repairs. Refrigerant is the “lifeblood” of the refrigeration machine, and its pressure and boiling point parameters are strictly calculated by engineers for a specific compressor. Next, we will look at how to independently find the necessary information and what to look for when diagnosing the system.
Determining the type of refrigerant by labeling
The most reliable way to find out what kind of gas is used in your Polair refrigerator is to study the technical documentation and factory tags. Manufacturers are required to display the type and quantity of refrigerant in a visible place. Usually this is a metal plate or sticker located on the inner wall of the chamber, on the back wall of the housing or on the compressor.
Pay attention to the column Refrigerant or Refrigerant type. There will be a code starting with the letter R. For Polair equipment, the most common designations are R134a (tetrafluoroethane) or R600a (isobutane). Also, the exact amount of the substance in grams is always indicated next to it, for example 130±5g. This value is critically important when refilling.
⚠️ Attention: If the manufacturer's tag is damaged, erased or missing, do not under any circumstances try to guess the brand of freon. Filling with the wrong gas can cause a chemical reaction with the oil in the compressor, which will lead to complete seizure of the motor.
Sometimes the markings are duplicated on the compressor. Find the sticker on the unit itself (usually the black “barrel” on the back of the refrigerator). It will also indicate the type of compatible refrigerant. If the tag says R134a, and you refill R600a, the system will not work correctly due to different oil solubilities and operating pressures.
Features of freon R134a in Polair equipment
Refrigerant R134a is the most common in Polair medium and large professional refrigeration equipment. This gas replaced the ozone-depleting R12 and has proven itself to be a reliable and safe option. It is non-flammable and non-toxic under normal operating conditions, which simplifies safety requirements during maintenance.
One of the key features of R134a is its operating pressure, which is higher than that of R600a. This means that system components such as the condenser and evaporator must withstand higher loads. The oil used in compressors with this freon is usually polyester (POE), which is very hygroscopic, that is, it actively absorbs moisture from the air.
When working with R134a, the following technical points must be taken into account:
- ⚙️ High sensitivity to moisture requires the use of high-quality filter-driers whenever the circuit is opened.
- 🌡️ The boiling point at atmospheric pressure is -26.3°C, which provides effective cooling over a wide range.
- 🔧 Evacuation of the system requires more powerful pumps and a long process time due to the molecular structure of the gas.
It is important to understand that R134a does not mix with mineral oils that were used in older systems. Therefore, when altering or repairing old equipment, it is necessary to completely flush the system or replace the compressor with a unit designed for synthetic oil and new gas.
Specific use of R600a (isobutane)
In recent years, Polair, following the global trend of energy efficiency, is increasingly using it in its refrigerators and freezers refrigerant R600a. It is a hydrocarbon gas that has excellent refrigeration properties and extremely low global warming potential. However, its use imposes strict restrictions on maintenance procedures.
The main feature of R600a is its flammability. In concentration with air, isobutane forms an explosive mixture. That is why the amount of charged gas in household and some professional models is strictly limited (usually up to 150 grams), so that in the event of complete depressurization, the concentration in the room does not reach a dangerous threshold.
Why is R600a more dangerous during repairs?
When working with R600a, it is strictly forbidden to solder pipelines without first purging the system nitrogen or vacuum. Residual gas in the tubes when heated by the burner may cause popping or fire. Also, you should not smoke or use open fire within a radius of 3 meters from the work site.
The technical characteristics of the system on R600a differ from R134a:
- 📉 Lower operating pressure, which reduces the load on the compressor and extends its service life.
- 🔇 Less noise during operation unit due to the properties of gas.
- 💰 Smaller amount of refrigerant required (usually 2-3 times less than for R134a of similar power).
When servicing such systems, the technician must have a special tool, spark-proof and calibrated specifically for hydrocarbons. Conventional pressure gauge stations used for R12 or R22 may have residues of other oils, which is unacceptable for R600a.
Comparative table of refrigerant characteristics
For ease of selection and understanding of the differences between the main types of gases used in Polair refrigerators, we provide a comparative table. This data will help you quickly navigate the technical requirements.
| Parameter | R134a (Tetrafluoroethane) | R600a (Isobutane) | R404a (Mixture) |
|---|---|---|---|
| Chemical formula | CH2FCF3 | C4H10 | Mixture R125/R143a/R134a |
| Flammability | Not flammable | Highly flammable | Non-flammable |
| Oil type | Polyester (POE) | Mineral (MO) or POE | Polyester (POE) |
| Boiling pressure | High | Low | Very high |
| Application in Polair | Medium cabinets, display cases | Household, small cabinets | Low-temperature freezers |
As can be seen from the table, R404a is also found in the Polair line, but mainly in low-temperature equipment (chest freezers, blast freezing chambers). This gas operates at significantly higher pressures and requires a professional approach. Replacement changing one type of freon to another without changing the system design and changing the oil is strictly prohibited.
Signs of a leak and the need for refilling
You can determine that the Polair refrigerator has run out of freon by a number of indirect signs. A sealed circuit does not allow for natural gas flow, so if cooling stops, there is a leak. Ignoring this symptom will lead to overheating and combustion of the compressor, since freon is also a coolant for cooling the motor.
What you should pay attention to first:
- ❄️ The products have stopped freezing or cooling, the temperature in the chamber corresponds to room temperature.
- 🔊 The compressor works continuously, without turning off, trying to gain temperature, or, conversely, it turns on for a second and stalls.
- 👀 Visual traces of oil at pipeline connections (freon carries oil with it, so greasy spots are a sure sign of a hole).
Sometimes the leak can be microscopic, and the process of gas loss takes months. In this case, the refrigerator will work, but with frequent switching on. You can check for the presence of gas by touching the condenser (the grille on the back or sides). If it is cold or warm only at the outlet of the compressor, and not along the entire length, there is little or no gas in the system.
⚠️ Attention: If you find a leak, a simple “top-up” will not solve the problem. The gas will escape again through the same hole. It is necessary to find the location of the leak (using the soaping method or a leak detector), eliminate it and only then refill the system.
The process of refilling and vacuuming
The procedure for refilling a Polair refrigerator is a technically complex process that requires specialized equipment: a vacuum pump, manometer station, scales and burner device. An attempt to fill the refrigerator “by eye” or without evacuation is doomed to failure.
Main stages of proper repair:
- Removing residual old gas and oil.
- Filling the system with nitrogen to check the tightness (pressure testing).
- Evacuating the circuit to remove moisture and air.
- Weighted filling of the exact amount of freon.
- Sealing the process fitting.
☑️ Checklist for preparation for refueling
The critical stage is vacuuming. The moisture remaining in the system, upon contact with the refrigerant and oil, forms an acid that corrodes the compressor windings from the inside. The vacuuming time depends on the pump power and the volume of the system, but usually it is at least 30-40 minutes until a deep vacuum is achieved.
The amount of gas charged must strictly correspond to the data on the nameplate. A lack of freon will lead to poor cooling, and an excess will lead to an increase in condensation pressure, an increase in energy consumption and the possible activation of the emergency automatic compressor. Use only electronic scales to control the weight of the gas cylinder.
Frequently asked questions and answers (FAQ)
Is it possible to refill Polair R134a instead of R600a, if they are similar?
No, absolutely not. These gases have different operating pressures, boiling points and, most importantly, different oil requirements. A compressor designed for R600a and mineral oil will fail when working with R134a and polyester oil, or simply will not be able to create the required pressure for cooling.
Where to buy original freon for a Polair refrigerator?
Freon is a chemical substance, and the concept “original” is applied to it conditionally. The main thing is to buy gas from certified suppliers to avoid fakes with impurities. Gas brands (e.g. DuPont, Arkema, Honeywell) are more important than the refrigerator brand. Avoid buying gas on tap in markets without a guarantee of quality.
Why does the refrigerator freeze after refilling, but then stops?
Most likely, there is moisture or air left in the system, which freezes in the capillary tube, forming an ice plug. This blocks the circulation of freon. Another reason is poor soldering and repeated leakage. Re-opening, replacing the filter-drier and deep vacuuming are required.
Is it dangerous to breathe freon vapors from Polair?
In high concentrations, freon vapors displace oxygen and can cause suffocation. When heated (for example, from a cigarette), R134a decomposes to form phosgene, a chemical warfare agent. R600a is explosive. Therefore, any repair work and draining of gas should be carried out in a well-ventilated area.