When choosing a new household appliance For kitchen appliances, consumers often focus on functionality, energy efficiency and design, forgetting to look “under the hood.” However, it is refrigerator body that is the foundation that ensures durability, safety of the refrigerant and thermal insulation of the entire unit. Understanding what materials and layers it consists of will help you avoid buying a fragile device that will quickly lose its presentation or fail.
A modern refrigerator is a complex “sandwich”, where each layer performs a critical function. The outer shell protects against mechanical damage, the inner liner is in contact with the products, and thermal insulation is hidden between them. Let's look in detail at what is hidden behind the glossy or matte surface of your refrigerator.
External layer: metal, glass or plastic?
Traditionally, the main material for the outer cladding is cold-rolled steel. This is a durable, tough and relatively inexpensive material that can be easily painted with powder paints or covered with polymer films. A steel sheet with a thickness of 0.5 to 0.7 mm provides the necessary rigidity of the structure, protecting the insides from shocks and deformations during transportation.
In recent years, models with facades made of tempered glass (Glass-on-Steel or pure glass) have been gaining popularity. Such refrigerators look premium and are scratch-resistant, but require more careful handling during installation. Plastic in external panels is rarely used, mainly in budget segments or as decorative inserts, since it is less resistant to mechanical damage.
⚠️ Attention: If you choose a refrigerator with a coating Fingerprint Free (stainless steel), remember that it is sensitive to aggressive chemistry. Use only specialized products so as not to damage the protective layer.
The coating of the external surface also plays a role. In addition to classic enamel, manufacturers use textured coatings that imitate linen, stone or metal. This is not only aesthetics, but also a way to hide minor abrasions that inevitably appear during operation.
Internal liner: safety and hygiene
The internal part of the body, in direct contact with the products and air of the chamber, is called liner. Here the requirements for materials are radically different from external ones. The basic rule is absolute chemical inertness, odorlessness and resistance to bacterial growth. In 90% of cases, impact-resistant polystyrene (HIPS) or ABS plastic is used.
These materials allow you to form complex geometric shapes using vacuum stamping, creating shelves, ledges for drawers and channels for air circulation. Plastic must withstand low temperatures (up to -60°C in the freezer) and not crack upon impact, for example, when you place a heavy pan on a shelf.
- 🧊 Antibacterial additives: many manufacturers introduce silver or copper ions into the plastic to suppress the growth of microorganisms.
- 🛡️ Impact resistance: a high-quality liner should not chip if heavy products are accidentally dropped.
- 🌡️ Thermal stability: the material should not deform during sudden temperature changes during defrosting.
Particular attention should be paid to the quality of the joints. In cheap models, plastic panels can simply be glued together, while in the premium segment monolithic molding or hidden fasteners are used, which simplifies care and cleaning and prevents the accumulation of dirt in the cracks.
Why does the plastic inside turn yellow?
The yellowness of plastic (liner) is the result of oxidation of the material under the influence of UV rays (if the refrigerator is located near the window) or reaction with fat and food. Cheap types of plastic oxidize faster.
The heart of thermal insulation: polyurethane foam
Between the outer metal wall and the inner plastic liner is the most important layer - thermal insulation. In modern refrigerators this is polyurethane foam (PPU). It is on its quality and thickness that it depends how long the refrigerator will keep cold after a power outage and how much energy it will consume.
The filling process occurs by foaming liquid components directly inside the enclosed space of the case. The foam expands to fill all voids and hardens to form a rigid structure with millions of closed cells containing gas. Gas has low thermal conductivity, which provides an insulating effect.
| Parameter | Old models (Freon) | Modern models (Cyclopentane/CO2) |
|---|---|---|
| Filler gas | Freon R-141b | Cyclopentane, CO2 |
| Environmentally friendly | Destroys the ozone layer | Safe for nature |
| Thermal conductivity | Higher (poorer heat retention) | Lower (better insulation) |
| Foam density | Less homogeneous | High, uniform |
The quality of foaming directly affects the noise level. If the foam is spread unevenly or voids have formed, vibrations from the compressor will be transmitted to the housing, creating a hum. A good refrigerator body should be a monolithic insulation block.
Refrigerator door: complex design
The door is the most movable and loaded element of the body. Its structure is more complex than that of the cabinet walls. It also uses the sandwich principle, but with a reinforced structure for attaching shelves and handles. The outer sheet of metal is often double rolled along the edges for strength.
Inside the door cavity there is a system No Frost (if provided by the model), including fans, defrost heaters and grooves for condensate drainage. Therefore, the inner wall of the door often has a complex shape with protrusions and niches, in contrast to the smooth walls of the main chamber.
- 🚪 Seals: a magnetic seal is installed around the perimeter of the door, which should fit tightly to the body without leaving gaps.
- ⚖️ Hinges: the places where the hinges are attached are reinforced with metal inserts inside the body so that the door does not sag under the weight of products.
- ❄️ Thermal circuit: in some models, along the perimeter of the door there is a refrigerant circuit or a heating element that prevents the formation of condensation ("crying" doors).
⚠️ Attention: Do not try to re-hang the doors yourself on models where this is not provided for in the instructions. There may be hidden channels for freon or wiring inside the case, damage to which will lead to a gas leak or short circuit.
Rear wall and technical elements
The back of the refrigerator body is the technical area. There is a capacitor (radiator grille) located here, which in modern models is often hidden inside the case, foaming it along with the walls. This improves aesthetics and protects the radiator from dust and damage.
In the lower part at the back there is a niche for the compressor. The housing in this area has a reinforced structure, since vibrations are maximum here. Often the bottom is made of thicker metal or plastic with stiffeners. This is where the holes for ventilation are located, which absolutely cannot be closed..
The material of the back wall inside the chamber (where the evaporator is located) is also important. In No Frost systems, this is plastic, behind which the evaporator is hidden. In drip systems, the back wall can be metal (aluminum) for better heat transfer, but covered with a protective layer.
☑️ Check the integrity of the body upon delivery
Environmental friendliness and safety of materials
Modern production of refrigerators is strictly regulated by environmental standards. This applies not only to refrigerants, but also to housing materials. Plastics used internally must be Food Grade certified.
Paints and exterior coatings must not contain heavy metals such as lead or cadmium, which could evaporate when heated (for example, if the refrigerator is placed next to a stove or in the sun). The use of volatile organic compounds (VOCs) is also reduced during production.
When disposing of old refrigerators, they require special processing. The metal body is melted down, the plastic is sorted, and the polyurethane foam is often incinerated with energy recovery or landfilled, since its recycling is economically difficult. Choosing a durable model is also a contribution to the environment.
Frequently asked questions (FAQ)
Is it possible to paint the refrigerator body on your own?
Yes, it is possible, but it requires preparation. It is necessary to use special aerosol paints for household appliances or epoxy enamels that are resistant to temperature changes. Before painting, the surface must be degreased and primed. However, the factory coating is always stronger.
Why do the side walls of the refrigerator get hot?
In modern models, condensation grilles are often built into the side walls of the case. Heating to 40-50°C in these zones is a normal operating process for heat removal, and not a sign of a malfunction.
What are the dangers of dents on the refrigerator body?
Small dents on the outer panel are only a cosmetic defect. However, if the dent is deep and breaks the tightness of the inner layer or damages the foam contour, moisture can get inside, which will lead to corrosion and destruction of the thermal insulation.
What are the shelves inside the refrigerator made of?
The shelves are made of tempered glass (triplex), which can withstand weight up to 25-40 kg, or of durable metal plastic coated gratings. Glass is safe: when broken, it crumbles into small, non-sharp crumbs.