Some Of General Information On Air DuctsThe second category of ductwork is stiff ductwork. Stiff ducts can be different sizes and made from various products, and they can be either rectangular or round. Due to the fact that the ducts are stiff, they do not have the threat of kinks or bends restricting airflow and, unlike flexible ducts, they can not be torn or punctured.However, sheet metal ducts are more most likely to experience leakages where 2 sections are joined.: Some sheet metal ducts…See More