Everyday Life & Technology
How does a refrigerator keep food cool?
Puschel imagines a little ice cloud behind the door.
The short answer
A refrigerator moves heat from inside to outside. A special fluid in closed pipes takes in heat inside and releases it outside. The appliance needs electrical energy to do this. It does not simply create new cold.
An imagined Wusel scene
Puschel and Flauschi investigate
Puschel stands in front of a closed refrigerator. Puschel“Has a little ice cloud moved in?”
Flauschi“No. The refrigerator moves heat from inside to outside.”
Puschel looks at the door. Puschel“So it is more of a heat transporter!”
Flauschi“Exactly. Refrigerant absorbs heat inside. The circuit releases it outside again. The appliance needs energy for that.”
Puschel“Then I will keep the door shut until we really need something.” They decide what to fetch first. The ice cloud can stay imaginary.
Little Wusel quiz
What does a refrigerator move out of its interior?
Choose one answer: a), b).
- a)Heat.
- b)All the air in the refrigerator.
Show answer
Correct answer: a): Heat. It moves heat from the interior to the outside.
Why do we avoid leaving the door open?
Choose one answer: a), b).
- a)To let less heat enter from outside.
- b)So warm room air cools the food faster.
Show answer
Correct answer: a): To let less heat enter from outside. So less heat gets in from outside.
Word help
- evaporation
- Liquid becomes gas at its surface, even without boiling.
- circuit
- A closed path through which electric current can flow.
Explore in more detail
Here you will find longer explanations and further details. You can explore them together.
Understand step by step
How it works – simply explained
Take heat from inside
Refrigerant flows through sealed pipes. Evaporating absorbs heat from the interior, cooling food.
Release heat outside
An electric pump, the compressor, compresses the gas. Later in the circuit it releases heat to the room and becomes liquid again. The cycle repeats.
The door slows incoming heat
The room is usually warmer. Insulation and a closed door slow heat entering. A fridge does not create cold from nothing: it moves heat using energy.
Why cooling can also warm the room
Food gives heat to refrigerant. The refrigerator moves this heat outside and also releases energy from its electrical operation as heat. It can therefore cool its interior while adding heat to the room. An open door does not reliably cool a room. Keep opening brief and never examine pipes or rear components by touch.
The key points again
Discovery 1
A refrigerator moves heat from its interior to the outside.
Discovery 2
In typical refrigerators, a special substance called refrigerant flows through closed pipes. When it changes from a liquid into a gas, it absorbs heat. This is called evaporation. The compressor is an electrically powered pump that squeezes the gas and moves it around the circuit.
Discovery 3
A closed door and insulation help less heat get in from outside. Insulation is a protective layer in the refrigerator walls that lets heat pass through only slowly.