What occurs in a refrigeration system when the pressure is lowered?

When the pressure in a refrigeration system is lowered, the temperature of the refrigerant also decreases. This relationship is a fundamental principle of thermodynamics, specifically described by the ideal gas law and the refrigeration cycle.

In a refrigeration system, refrigerants absorb heat from the surroundings at low pressure and temperature before being compressed and cycled back to a high-pressure, high-temperature state. As the pressure decreases, the boiling point of the refrigerant also lowers, which allows it to evaporate at a lower temperature. This evaporation process is essential for heat absorption, as it enables the refrigerant to absorb heat effectively from the environment, thus cooling the surrounding space.

Consequently, when pressure is reduced in the system, the refrigerant's capability to absorb heat increases, resulting in a decrease in temperature. This principle is why minimizing pressure in specific parts of the refrigeration cycle, such as during evaporation, is crucial for effective cooling.