A branch duct will convey air at a volumetric flow rate of 5000 ft3 /min. The pressure loss available for this duct is 0.1 in w.c./100 ft. The duct is not lined.
a. Identify the minimum diameter of a round duct.
b. Identify a cost-effective rectangular duct section with an equivalent pressure loss that has a side depth of 20 in.