Using the equal friction method (e.g., 0.08 to 0.12 in. w.g./100 ft), you can size ducts using a friction chart approximation.
Store a friction loss vs. CFM vs. diameter table. Use INDEX/MATCH or linear interpolation to find the nearest duct diameter for a given CFM at your target friction rate. hvac design calculations excel
Used to size ducts and fans. The standard formula is: Using the equal friction method (e
Professionals often use the , a standardized format for breaking down cooling loads by segment. Using the equal friction method (e.g.