The subcooling effect of refrigerant just before the expansion valve primarily increases what?

The subcooling effect of refrigerant just before the expansion valve primarily increases the refrigeration effect. Subcooling occurs when the refrigerant is cooled below its saturation temperature at a given pressure. This process enhances the refrigerating capacity of the system because the refrigerant entering the expansion valve is in a more liquid state, which allows for more efficient evaporation in the evaporator.

When the refrigerant is subcooled, it can absorb more heat as it evaporates, leading to a greater temperature difference between the refrigerant and the surrounding medium (air or water), ultimately providing more effective cooling. This capability improves the overall efficiency and performance of the refrigeration cycle, allowing the system to remove more heat from the environment it is cooling.

In contrast, while options related to horsepower, expansion valve capacity, and refrigerant flow have their importance within the refrigeration cycle, they do not directly correlate to the benefits provided by subcooling before the expansion valve like the refrigeration effect does.