intended for HVAC designers, practicing engineers, draftsmen, consultants, contractors, and designers for Spiralite brand circular and flat oval ductwork. Spiralite is innovative and patented ductwork from Khansaheb Industries offering customers unique circular and flat oval shapes for pre-insulated ductwork. The sizing of ductwork plays a very important role in HVAC design. In this application with we can play with four duct sizing parameters to reach at optimal solution. In this application the duct sizing and other performance parameters are calculated based on standard formulae. Spiralite Round shape Duct required velocity is less compared to the rectangular ductwork due to the curved surfaces, also the round shape has less surface area which offers better airflow & leads to reduced chance of dirt & grime accumulating inside the ducts. Furthermore, Spiralite duct is light in weight when compared to metal ductwork which makes it easy to install, it has better IAQ & less carbon footprint & maintains better noise criteria.