As suction pressure increases, what happens to the horsepower in a refrigeration system?

In a refrigeration system, horsepower is closely related to the work done by the compressor, which is influenced by the suction pressure. When the suction pressure increases, it indicates that the refrigerant entering the compressor is at a higher pressure. The compressor does less work to compress the refrigerant because it starts at a higher pressure, which generally leads to a decrease in the amount of energy (horsepower) required to achieve the desired refrigeration effect.

This relationship is rooted in the thermodynamic principles governing refrigeration cycles. A higher suction pressure means that the compressor has an easier task of compressing the refrigerant to the discharge pressure, which directly affects the horsepower consumed by the compressor. Therefore, as suction pressure goes up, the required horsepower decreases since the compressor operates more efficiently with less work needed to raise the refrigerant's temperature and pressure.

By understanding this dynamic, one can see why the horsepower decreases with an increase in suction pressure, making this the correct answer for the question posed.