This is a technical white paper prepared on the application of duct sizing tools in HVAC design. White Paper: Optimizing Air Distribution – The Application and Principles of the McQuay Duct Sizer 1. Introduction In Heating, Ventilation, and Air Conditioning (HVAC) system design, duct sizing is a critical factor affecting initial capital cost, energy consumption, and acoustic performance. While McQuay International (now integrated into Daikin Applied) is primarily renowned for chillers, air handlers, and fan coils, the engineering legacy of "McQuay Duct Sizer" refers to both a specific slide-rule calculator and the design methodology embedded in their selection software.
| Airflow (CFM) | Round Duct Dia (in) | Velocity (FPM) | Friction Loss (in wg/100ft) | |---------------|---------------------|----------------|-----------------------------| | 500 | 10 | 917 | 0.10 | | 1000 | 14 | 935 | 0.10 | | 2000 | 20 | 917 | 0.08 | | 4000 | 26 | 1085 | 0.10 | | 8000 | 36 | 1132 | 0.09 | duct sizer mcquay