In addition to the HVAC Duct Construction Standard—Metal and Flexible manual, Sheet Metal and Air-conditioning Contractors’ National Association (SMACNA) has developed an app for designing ducts. It includes information regarding options for rectangular ducts with dimensions up to 3048 mm (120 in.) for applications from negative to positive 254-mm (10-in.) water gage as described in the print manual. The most common installation options are included as part of the app, but it is intented to be used in combination with the manual, an American National Standard (ANSI). The app is available for purchase for both Android and iOS. For more information, visit www.smacna.org.