Refrigerators: How Machines Move Heat Against Nature

Refrigerators keep things cold by moving heat out of the inside, not by making “cold.”
They work against nature, pumping heat from a cooler space to a warmer room.
A refrigerant fluid absorbs heat inside, then releases it outside through coils.
Compression makes the refrigerant hot, expansion makes it cold—cycling endlessly.
The Second Law of Thermodynamics allows this only with added work from electricity.
That’s why the back of a fridge feels warm while the inside stays cool.
Freezers use the same principle, just at lower temperatures for deeper cooling.
Air conditioners are really refrigerators for entire rooms or buildings.
Efficiency matters—better insulation and smart compressors save both energy and money.
From kitchen fridges to spacecraft cooling systems, this tech makes modern life possible.