What is the acceptable minimum gas velocity that should be maintained in a horizontal suction line?

The acceptable minimum gas velocity that should be maintained in a horizontal suction line is crucial for ensuring proper refrigerant flow and minimizing the risk of refrigerant pooling or oil migration. A velocity of 750 feet per minute (fpm) is widely accepted in the industry as it strikes a balance between effective refrigerant transport and minimizing pressure drop.

Maintaining a minimum velocity of 750 fpm helps ensure that the refrigerant remains in a gaseous state and that any oil mixed with the refrigerant is carried along with it. This is particularly important in systems that rely on the return of oil to the compressor to maintain lubrication and prevent premature wear. When the velocity is too low, the risk of liquid refrigerant pooling in the line increases, which can lead to compressor damage if liquid returns to the compressor.

While higher velocities can improve refrigerant transport, they may also result in increased energy consumption and potential wear on the system components. Thus, 750 fpm is a standard that balances efficiency and safety in refrigeration practices, making it the correct choice for this scenario.