The fourth edition of HVAC Systems Duct Design presents the basic methods and procedures required to design HVAC air distribution systems. This manual provides the HVAC system designer detailed information on duct design and U.S. and metric units are provided in all examples, calculations, and tables. In addition to the basic engineering guidelines for the sizing of HVAC ductwork systems, the manual also provides related information on materials, methods of construction, economics of duct systems, duct system layout, pressure losses, fan selection, duct leakage, acoustic considerations, and Testing, Adjusting and Balancing (TAB).