What material is typically used for the construction of nonmetallic ducts?

Nonmetallic ducts are most commonly constructed from plastic, which is preferred for several reasons. Plastic ducts, such as those made from polyvinyl chloride (PVC) or polypropylene, are lightweight, resistant to corrosion, and easier to install compared to metallic alternatives. They are also effective at preventing air leakage, which can enhance the overall efficiency of HVAC systems.

Fiberglass, while also used in some applications, primarily refers to insulation rather than duct material itself. Therefore, plastic stands out as the predominant choice for nonmetallic duct construction due to its favorable properties and performance in varied environments. Metal options like aluminum and steel are typically not considered nonmetallic and thus do not apply in this particular context.