A fridge is made of an outer metal cabinet, a moulded plastic inner liner, rigid polyurethane foam insulation between those shells, a sealed cooling circuit, a compressor, a door and magnetic gasket, shelves, controls and wiring. Steel provides the structure, plastic creates a cleanable food compartment, and the PU foam slows heat entering the cabinet.
The main parts of a fridge work as connected systems. The sealed refrigeration circuit moves heat, fans and ducts distribute cooled air on applicable models, sensors and controls regulate operation, the defrost system manages frost on frost-free models, and the cabinet, insulation and door gasket limit heat and moisture entering the compartments. Exact parts vary by design and model.
What Is a Fridge Made Of? Materials at a Glance
| Fridge area | Common material or assembly | What it does |
|---|---|---|
| Outer cabinet | Coated sheet steel | Supports the appliance and protects the insulated cabinet |
| Inner liner | Formed thermoplastic, commonly ABS or HIPS depending on the design | Creates the cleanable food compartment |
| Insulation layer | Rigid polyurethane foam | Fills the space between the outer cabinet and inner liner and limits heat transfer |
| Cooling circuit | Metal tubing, heat exchangers, compressor and refrigerant | Moves heat from inside the cabinet to the room |
| Door assembly | Metal or plastic panels, PU insulation and a flexible magnetic gasket | Insulates the opening and maintains the seal |
| Shelves and drawers | Glass, coated wire and moulded plastics | Supports and separates stored food |
| Controls and wiring | Sensors, circuit boards, copper conductors and plastic insulation | Monitors temperature and controls operation |
Steel, plastic and PU foam become the fridge’s main components through forming, assembly and cabinet foaming. For a closer look at cabinet skins, liners and injected insulation, read our refrigerator materials breakdown.
Materials and components are not the same thing. Steel, plastic and polyurethane are materials; the cabinet, liner, insulated door and cooling circuit are components made from them. In production, the outer shell and inner liner are assembled first, and rigid PU foam is then introduced into the closed cavity. The cooling system and controls are separate assemblies installed and tested around that insulated cabinet. See how these stages fit into refrigerator and freezer production.
Fridge Main Parts and What They Do
| Part or system | What it does | Important boundary |
|---|---|---|
| Compressor | Circulates refrigerant through the sealed system | A no-cooling symptom alone does not prove compressor failure |
| Condenser | Releases heat to surrounding air | Location and airflow arrangement vary by model |
| Expansion device | Produces the pressure change before the evaporator | Sealed-system diagnosis requires suitable training and tools |
| Evaporator | Absorbs heat inside the appliance | A frost observation is not a universal diagnostic test |
| Evaporator fan | Moves cooled air on applicable models | Not installed or arranged identically in every design |
| Condenser fan | Moves air across applicable condensers | Some condenser arrangements do not use this fan |
| Thermistor or thermostat | Senses or regulates temperature | Values and test procedures are model-specific |
| Electronic control | Coordinates sensors, loads and operating logic | Check error codes against exact model documentation |
| Defrost heater, sensor and control | Manage evaporator frost on frost-free models | More than one component can produce the same symptom |
| Door gasket | Limits warm, moist air entering | Dirt, damage, alignment and obstructions all matter |
| Damper and ducts | Route or regulate air on applicable models | Blocked vents and loading can mimic a component fault |
Do not apply universal resistance, pressure, wattage or temperature figures to these parts. Specifications and test procedures differ by manufacturer and model.
How the Refrigeration Cycle Uses the Main Parts
- The compressor raises the pressure of the refrigerant vapour.
- The condenser releases heat to the room and condenses the refrigerant.
- The expansion device reduces pressure.
- The evaporator absorbs heat as the refrigerant evaporates.
- Refrigerant returns to the compressor and the cycle repeats.
This is a simplified overview, not a sealed-system repair procedure. Refrigerant choice, tubing layout, fan arrangement and control logic depend on the refrigerator design.
Cabinet, Liner, Door and Insulation
The coated-steel outer cabinet provides the main protective shell. Inside it, a formed thermoplastic liner creates a smooth, cleanable food compartment. ABS and HIPS are common liner materials, but the exact resin and grade must come from the approved material specification for the refrigerator model.
The door is another insulated assembly. Its outer and inner panels surround an insulation cavity, while the flexible magnetic gasket closes the gap between the door and cabinet. Shelves, drawers, hinges, lighting and controls are installed around this insulated structure according to the appliance design.
Rigid PU Foam Inside a Refrigerator
Rigid PU foam is used inside the cabinet and door as thermal insulation; it is not the soft cushioning foam used in furniture. The final insulation result depends on the approved chemical system, cabinet geometry, fill pattern, process control and curing conditions—not on a foaming machine name alone.
In manufacturing, a high-pressure refrigerator cabinet foaming machine can meter, mix and dispense the specified reactive components into the closed cabinet or door cavity. The equipment and process must be matched to the chemical supplier’s data, cabinet design, production rate and safety requirements.
Energy claims should be tied to a tested refrigerator model rather than attributed to one material in isolation. ENERGY STAR’s refrigerator guidance explains appliance-level efficiency and certification, while the U.S. EPA’s SNAP information for foam-blowing agents provides regulatory context for blowing-agent choices. Confirm the chemical supplier’s technical and safety data and the destination market’s rules before specifying a system.
Symptom Clues Are Not a Parts Diagnosis
| Symptom | Safe preliminary checks | Why diagnosis may still be needed |
|---|---|---|
| Fridge is warm but lights work | Settings, door closure, blocked vents and required clearance | Fans, sensors, controls, frost and sealed-system faults overlap |
| Frost or ice builds up | Door closure and gasket condition | Defrost components and airflow need model-specific tests |
| Unusual noise | Note where and when; separate touching containers | Fan, compressor and normal refrigerant sounds can be confused |
| Water appears inside or below | Visible spills and user-manual drain guidance | Drain routing, ice systems and leaks vary by model |
| Compressor appears to run often | Recent loading, door opening, room temperature and ventilation | Control, airflow and sealed-system performance require measurement |
Unplugging an appliance may not remove every hazard. Stored electrical energy, moving parts, sharp edges and refrigerant work can require trained service. Follow the manufacturer’s instructions and use a qualified technician when the user manual does not cover the task.
How to Identify the Correct Refrigerator Part
Before contacting a supplier or service provider, collect the complete model and serial number, the part number from official model documentation when available, photos of the label and connections, the electrical rating, the observed symptom and any displayed error code. Matching by appearance alone is unreliable because similar-looking parts may have different ratings, firmware, connectors, geometry or temperature characteristics.
Keep three questions separate: what the component does, which component fits the exact refrigerator, and which component caused the fault. The first is educational; the second requires model-specific documentation; the third requires diagnosis.
Frequently Asked Questions
What is a fridge mostly made of?
A fridge combines a coated steel outer cabinet, a formed plastic inner liner and rigid polyurethane foam insulation. It also contains a sealed cooling circuit, compressor, door gasket, shelves, controls and electrical wiring. “Mostly” depends on whether it is measured by weight, volume or function, so the page should not claim one universal percentage.
What plastic is used inside a fridge?
Refrigerator liners and interior parts are commonly made from formable thermoplastics such as ABS or HIPS, but the exact resin depends on the component and manufacturer specification. The approved material sheet for the refrigerator model is the final reference.
What insulation is inside a refrigerator?
Many modern refrigerator cabinets and doors use rigid polyurethane foam inside the closed space between the outer shell and inner liner. The foam limits heat transfer; its formulation and processing conditions must match the cabinet design and applicable safety and environmental requirements.
Are refrigerators made of steel or aluminium?
Both metals may appear in a refrigerator, but they do different jobs. Coated sheet steel is commonly used for the cabinet structure, while the cooling circuit and heat exchangers can use copper, aluminium or a manufacturer-specific combination. Do not infer the exact construction without the model’s bill of materials.