Changing the pressure upon a refrigerant affects which of the following?

Changing the pressure of a refrigerant has a direct impact on both the boiling point and the condensing point. This relationship is fundamental to the principles of thermodynamics as they relate to refrigeration cycles.

When the pressure of a refrigerant is increased, its boiling point rises. This means that the refrigerant requires a higher temperature to boil and change from a liquid to a vapor. Conversely, when the pressure is decreased, the boiling point lowers, allowing the refrigerant to vaporize at a lower temperature.

On the other hand, the condensing point is also affected by pressure changes. Increasing the pressure raises the condensing point, meaning that the refrigerant condenses back into a liquid at a higher temperature. Lowering the pressure allows for condensation to occur at lower temperatures.

This interdependence between pressure and temperature is crucial for the effective operation of refrigeration systems, as they rely on the cycling of refrigerant between these two states for heat absorption and rejection. Thus, the correct choice highlights the comprehensive influence of pressure changes on both phases of the refrigerant's cycle.