Question: Refer to Problem and redesign the system with rectangular ducts. Specify a fan from a manufacturer's catalog.
Problem: A draw-through air-handling unit (AHU) will be used to supply conditioned air as shown in the schematic drawing below. Within the AHU assembly, the filter section has a pressure loss of 0.10 in. wg, the heating/cooling coil section has a pressure loss of 0.20 in. wg, and the casing has a miscellaneous loss of 0.05 in. wg. The AHU is a modular unit complete with a fan that can produce 0.60 in. wg of total pressure at the required design flows. Design a round ductwork system, ensuring that the location of and pressure drops across appropriate dampers for balancing the system is clear for the convenience of the mechanical contractor and the client.
