Which material is NOT typically used for rigid duct construction?

Which material is NOT typically used for rigid duct construction?

• A. Copper
• B. Galvanized steel
• C. Polyurethane
• D. Fiberglass

Answer: (A)

Rigid ductwork is usually made from metal such as galvanized steel or aluminum because these materials provide the strength, durable joints, and fire-rated performance needed for duct systems. Fiberglass is used in rigid duct forms (like duct boards or lined ducts) to add insulation and reduce heat transfer, while polyurethane is typically applied as insulation around metal ducts to improve energy efficiency. Copper, although excellent for piping and some specialized uses, is not common for rigid duct construction due to cost, fabrication, and fitting challenges. So copper is the material not typically used for rigid duct.

Rigid ductwork is usually made from metal such as galvanized steel or aluminum because these materials provide the strength, durable joints, and fire-rated performance needed for duct systems. Fiberglass is used in rigid duct forms (like duct boards or lined ducts) to add insulation and reduce heat transfer, while polyurethane is typically applied as insulation around metal ducts to improve energy efficiency. Copper, although excellent for piping and some specialized uses, is not common for rigid duct construction due to cost, fabrication, and fitting challenges. So copper is the material not typically used for rigid duct.