Keeping food fresh on the road or on a picnic is impossible without a correct understanding of how thermal systems work. Many users mistakenly believe that the material of the bag walls itself creates cold, but special ones play a key role here. It is these elements, placed inside the thermal container, that are responsible for maintaining a low temperature for a long time. cold accumulators. It is these elements, placed inside the thermal container, that are responsible for maintaining a low temperature for a long time.
In a professional environment and at home, these devices can be called differently: cold cells, ice briquettes or phase accumulators. Regardless of the name, the principle of their operation is based on the physical process of the phase transition of a substance from a solid to a liquid state, during which heat is actively absorbed from the environment.
To achieve maximum efficiency, it is important not only to know what are the names of the cooling elements for the refrigerator bag, but also understand the difference in their chemical composition. Using the wrong type of refrigerant may result in food spoilage or damage to the insulated bag itself. In this article we will analyze in detail all the nuances of choosing and operating these irreplaceable helpers.
Phase drives: operating principle and features
The most common type of cooling elements are phase storage devices. They work by using substances that freeze at temperatures below 0°C but melt at temperatures around -18°C or -20°C. This allows them to retain cold much longer than ordinary water ice.
The internal contents of such briquettes are a saline solution or a special water-based gel. When frozen, the solution crystallizes, forming a dense structure. During the melting process, it absorbs a huge amount of thermal energy, without changing its own temperature until it completely transforms into the liquid phase.
It is important to note that phase refrigerants are safe for humans if the seal of the packaging is not broken. However, they should not be used as toys or heating pads, as the chemical composition may cause irritation upon contact with the skin. The service life of quality phase elements usually ranges from 3 to 5 years, provided they are used correctly.
⚠️ Attention: Never attempt to open the phase accumulator case. The contents are a chemical reagent, which, if ingested, requires immediate gastric lavage and medical attention.
Gel batteries and their advantages
The second popular type is gel batteries. Unlike phase ones, they often remain plastic even at low temperatures, which makes them convenient for packing into bags of complex shapes. The gel does not spread if the packaging is accidentally damaged, which is their main advantage.
Such elements are often used in medical bags for transporting vaccines or donor organs, where temperature stability is critical. The gel base allows you to more evenly distribute the cold inside the volume of the thermal bag, eliminating the formation of “warm zones”.
For household use gel briquettes are ideal, as they are easy to clean and odorless. They can be frozen and thawed repeatedly without loss of effectiveness. The dense structure of the gel prevents rapid melting, ensuring long-term preservation of cold even in hot weather.
- ❄️ High plasticity allows you to place elements between products.
- 🛡️ Safety: the gel does not spread if damaged housing.
- ⏳ Long service life up to 500 freeze-thaw cycles.
Dry ice: extreme cold for long trips
When it comes to preserving food for several days, dry icecomes to the rescue. It is the solid form of carbon dioxide (CO2) and has a temperature of -78.5°C. This is not just a cooling element, but a powerful refrigerant that can freeze even those products that only need to be cooled.
The use of dry ice requires special care. When changing from a solid to a gaseous state (sublimation), it bypasses the liquid phase, immediately turning into a gas. This means that there will be no water in the bag, but the volume of gas will constantly increase, which can lead to swelling or rupture of the sealed bag.
Dry ice It is strictly forbidden to touch with bare hands - an instant burn is guaranteed. It should also not be stored in completely enclosed areas without ventilation, as the release of large amounts of CO2 can be hazardous to breathing. This is a choice for professionals or experienced tourists.
Where to buy dry ice?
Dry ice is rarely sold in regular supermarkets. It can be purchased at specialized industrial gas stores, from catering equipment suppliers, or in large construction hypermarkets in the garden equipment department.
| Element type | Freezing temperature | Cold duration | Safety |
|---|---|---|---|
| Water ice | 0°C | 2-4 hours | Absolutely safe |
| Phase storage | -18°C ... -20°C | 8-12 hours | Safe if intact |
| Gel battery | -15°C ... -25°C | 10-15 hours | High (gel does not leak) |
| Dry ice | -78.5°C | 24-48 hours | Requires gloves |
How to properly freeze refrigerants
The efficiency of the cooler bag directly depends on how well you have prepared cooling elements. Simply placing them in the freezer is not enough. It is necessary to ensure uniform freezing of the entire volume of the substance inside the briquette.
For water ices and phase accumulators, it is critical to leave an air cushion. When water freezes, it expands by about 9-10%. If the container is filled to the brim, the plastic casing may burst if it freezes. Manufacturers usually leave free space, but additional checking will not hurt.
The optimal freezing time is at least 10-12 hours at a temperature of -18°C or lower. If you use the "super freeze" mode, the process will be faster, but it still takes time for the gel structures to fully crystallize. An under-frozen element will begin to melt immediately after being placed in the bag, without giving away complete cold.
☑️ Preparing for freezing
⚠️ Attention: Do not place warm or room temperature refrigerants next to already frozen foods in the freezer. This will increase the temperature in the chamber and can ruin other supplies.
Rules for placing in a thermal bag
Knowing what the cooling elements for a refrigerator bag are called is less important than knowing how to position them correctly. Cold air is heavier than warm air, so it always tends to sink. Therefore, the main sources of cold should be from above of the products.
However, to create a uniform temperature field, it is recommended to surround the products with refrigerants on all sides. The ideal scheme is: a layer of briquettes at the bottom of the bag, then food, then another layer of briquettes, and a final layer at the very top. This “wrapper” minimizes heat loss.
Do not allow direct contact dry ice or heavily frozen phase elements with products that can spoil due to frost (vegetables, fruits, some dairy products). Use a layer of fabric, cardboard or newspaper to soften the effects of extremely low temperatures.
Care and storage of cooling elements
In order for your cold batteries to serve for a long time, they need to be properly looked after. After use, they should be washed with warm water and a mild detergent to remove any product residue or condensation. This will prevent the development of bacteria and the appearance of an unpleasant odor.
Thawed elements should be stored in a dry, cool place, away from direct sunlight. Ultraviolet light can break down plastic, making it brittle over time. It is also not recommended to store them near heating appliances.
Periodically check the packaging for leaks. If you notice cracks, swelling, or discoloration of the contents, it is best to discard the item. A damaged housing is a risk of a chemical reagent leaking onto the products, which will make them unfit for consumption.
Frequently asked questions (FAQ)
Is it possible to use ordinary water instead of special gel briquettes?
Yes, you can. Water frozen in plastic bottles is the most affordable alternative. However, it melts faster than phase accumulatorsand has a melting point of 0°C, which may not be sufficient for long-term storage of meat or fish. In addition, bottles can burst when freezing if you do not leave room for expansion.
How long do quality refrigerants keep cold?
The time depends on the quality of the bag, the ambient temperature and the amount of food. On average, good gel batteries in a quality bag keep the cold from 8 to 15 hours. Dry ice can maintain temperature for up to 2-3 days.
What to do if the contents of the briquette got on the food?
If it was ordinary water, it’s okay. If it was a chemical gel or saline solution, the products that were in direct contact with the substance must be thrown away. The remaining products should be washed thoroughly. The bag itself needs to be disinfected.
Is it possible to heat refrigerants for use as a heating pad?
Some gel elements are intended for use as heating pads (thermal accumulators). Their packaging usually has appropriate markings. Phase storage devices for refrigerators cannot be heated - this can lead to decomposition of the chemical composition and explosion of the housing.