Ducts and plenums serving a Type II hood shall be constructed of ______ materials.

Ducts and plenums serving a Type II hood shall be constructed of ______ materials.

• A. Wood
• B. Flexible non-metallic
• C. Rigid metallic
• D. Concrete

Answer: (C)

Ducts and plenums for Type II hoods must be built from noncombustible, durable metal to withstand heat and moisture and to be easily cleaned. Rigid metallic ductwork provides a noncombustible, smooth interior that resists corrosion and can be kept sanitary, which is essential for ventilation systems handling hot, moist exhaust. Wood is combustible and unsuitable for any kitchen exhaust ducting. Flexible non-metallic ducting can trap moisture and contaminants and is not consistently allowed for these systems by code. Concrete isn’t practical for routing and servicing ductwork. Therefore, rigid metallic materials are the appropriate choice.

Ducts and plenums for Type II hoods must be built from noncombustible, durable metal to withstand heat and moisture and to be easily cleaned. Rigid metallic ductwork provides a noncombustible, smooth interior that resists corrosion and can be kept sanitary, which is essential for ventilation systems handling hot, moist exhaust. Wood is combustible and unsuitable for any kitchen exhaust ducting. Flexible non-metallic ducting can trap moisture and contaminants and is not consistently allowed for these systems by code. Concrete isn’t practical for routing and servicing ductwork. Therefore, rigid metallic materials are the appropriate choice.