Why must liquid and suction line piping be sized large enough?

The correct answer emphasizes the importance of appropriately sizing liquid and suction line piping to handle the required amount of liquid or vapor. Proper sizing ensures that the system can efficiently transport refrigerants and other fluids without significant pressure drops or flow restrictions. When the piping is oversized, it can lead to issues like excessive heat gain in the liquid lines, while undersized piping can result in increased resistance, leading to inadequate refrigerant flow. This can severely affect the overall efficiency and performance of the HVAC system.

Adequate sizing also plays a critical role in maintaining the proper velocity of the fluid, which helps prevent issues such as liquid refrigerant carrying over into the compressor, leading to potential damage. Thus, it is essential that the piping is sized to accommodate the specific requirements of the system to ensure optimal performance and longevity.