What is the minimum round duct size required for a friction loss of 0.1" WC and 1,000 CFM?

To determine the minimum round duct size required for a friction loss of 0.1" WC while moving 1,000 CFM, we often reference duct size and friction loss charts or use duct design calculations.

At a friction loss of 0.1" WC, this indicates a relatively low resistance to airflow. For a set airflow rate of 1,000 CFM, the duct size must be sufficient to allow that volume of air to move through without creating excessive pressure loss that could impact system performance.

Using standard duct design principles, a round duct of 14 inches in diameter is typically required to deliver 1,000 CFM at a friction loss of 0.1" WC. This size strikes a balance between maintaining adequate airflow and minimizing energy losses due to friction. A smaller duct would likely lead to higher friction losses, compromising the system's efficiency and requiring more energy for air to be pushed through the ductwork.

Thus, selecting a duct size of 14 inches ensures optimal air delivery at the specified conditions, making it the correct choice.