Rigid ducts are made of which materials?

Rigid ducts are made of which materials?

• A. Copper, aluminum, and PVC
• B. Galvanized steel, polyurethane, and fiberglass
• C. Aluminum, fiberglass, and cardboard
• D. Bronze, brass, and cast iron

Answer: (B)

Rigid ducts are designed to keep their shape and withstand the flow of air, so they’re made from solid, durable materials. Galvanized steel is the standard metal choice because it’s strong and resists corrosion. Aluminum is another metal option when lighter weight is needed. Fiberglass fits in because rigid ducts often use fiberglass-based duct boards or panels, which provide both rigidity and insulation. Polyurethane serves as insulation for these systems, helping to prevent heat loss and condensation by being applied as foam insulation within or around the rigid duct assembly. Together, these materials cover the structural and insulating needs of rigid ductwork, which is why this combination is correct. Other materials listed aren’t typical for modern rigid HVAC ducts, and PVC isn’t standard for core duct construction in most residential and commercial applications.

Rigid ducts are designed to keep their shape and withstand the flow of air, so they’re made from solid, durable materials. Galvanized steel is the standard metal choice because it’s strong and resists corrosion. Aluminum is another metal option when lighter weight is needed. Fiberglass fits in because rigid ducts often use fiberglass-based duct boards or panels, which provide both rigidity and insulation. Polyurethane serves as insulation for these systems, helping to prevent heat loss and condensation by being applied as foam insulation within or around the rigid duct assembly. Together, these materials cover the structural and insulating needs of rigid ductwork, which is why this combination is correct. Other materials listed aren’t typical for modern rigid HVAC ducts, and PVC isn’t standard for core duct construction in most residential and commercial applications.