A refrigerator keeps food cold by moving heat from inside the cabinet to the surrounding room. It does this with a sealed loop of refrigerant, a fluid that changes between liquid and gas as it circulates.
Inside the refrigerator, the refrigerant passes through an evaporator coil at low pressure. It absorbs heat from the air and evaporates into a gas, cooling the interior. A fan often circulates the cooled air around the food compartments.
The compressor then squeezes the refrigerant gas, raising its pressure and temperature. The hot gas flows through condenser coils, usually located behind or beneath the refrigerator. There, it releases heat into the room and condenses back into a liquid.
Next, the liquid passes through an expansion device, which sharply lowers its pressure and temperature. The cold refrigerant returns to the evaporator, and the cycle repeats. A thermostat monitors the internal temperature and switches the compressor on and off as needed. The refrigerator’s insulation and door seals slow heat from entering, making the cooling process more efficient.