Gemini on Question 7, Sep 23

A refrigerator works by moving heat from the inside of its insulated compartment to the outside room, rather than by creating cold air out of nowhere. It relies on a continuous mechanical cycle and a chemical called a refrigerant, which easily transitions between a gas and a liquid based on pressure and temperature.

The cycle begins at the compressor, a motorized pump usually located at the bottom or back of the appliance. The compressor draws in warm refrigerant gas and squeezes it, which significantly raises both its pressure and its temperature. This hot, high-pressure gas is then pushed through the condenser coils, which are typically the warm metal tubes you can feel on the exterior back or bottom of the refrigerator. As the gas flows through these exterior coils, it releases its absorbed heat into the surrounding air of your kitchen. Losing this heat causes the refrigerant to condense, turning it from a hot gas into a high-pressure liquid.

This liquid is then forced through a tiny opening known as an expansion valve or capillary tube. When the liquid passes through this narrow passage into a wider area, it experiences a sudden and massive drop in pressure. This rapid pressure drop causes the liquid to expand and cool down drastically, becoming freezing cold.

The chilled liquid refrigerant then flows into the evaporator coils, which are located inside the refrigerator walls. A small fan blows the air from inside the fridge over these freezing coils. Because heat naturally moves from warmer objects to colder ones, the refrigerant absorbs the heat from the air and the food inside the appliance, leaving the inside air cold.

As the refrigerant absorbs all that heat from the interior, it warms up and reaches its boiling point, evaporating back into a low-pressure gas. Finally, this warm gas is drawn out of the evaporator coils and sucked back into the compressor, where the entire cycle begins all over again. Through this continuous loop of compressing, cooling, expanding, and absorbing heat, the refrigerator keeps your food safely chilled.