Gemini on Question 7, Sep 14

A refrigerator works by removing heat from its interior and releasing it into the surrounding room, rather than by creating cold air out of nothing. This process relies on a continuous cycle involving a chemical substance called a refrigerant, which constantly changes between a liquid and a gas as it moves through a closed system of tubes and components.

The cycle begins at the compressor, a pump typically located at the bottom or back of the appliance. The compressor squeezes the low-pressure refrigerant gas, significantly increasing its pressure and temperature. This hot, pressurized gas then flows into the condenser coils, which are the warm tubes located on the outside of the machine. As the hot gas travels through these coils, it releases its heat into the surrounding room air, causing the gas to cool down and condense into a high-pressure liquid.

The liquid refrigerant then travels toward an expansion valve or capillary tube, which acts as a tiny bottleneck in the system. Forcing the liquid through this small opening causes a rapid drop in pressure, which in turn makes the temperature of the liquid plummet. This freezing cold liquid then flows into the evaporator coils situated hidden inside the refrigerator compartment.

As the relatively warm air from inside the fridge passes over these cold coils, the refrigerant absorbs the heat from the food and the interior air. Absorbing this heat causes the cold liquid refrigerant to evaporate and turn back into a low-pressure gas. A small fan inside the appliance circulates the newly chilled air throughout the food compartments to keep everything cold. Meanwhile, the warmed refrigerant gas is drawn back down into the compressor to start the entire process over again. By constantly repeating this loop of pressure and temperature changes, the refrigerator steadily pumps heat out of its insulated interior to keep your food fresh.