What material and thickness is required for exhaust fan housings?

The requirement for exhaust fan housings, as outlined in NFPA 96, emphasizes the need for durability and fire resistance in materials used for ventilation systems in commercial cooking operations. The correct choice specifies that fan housings must be constructed from either carbon steel with a thickness of .054 inches or stainless steel with a thickness of .043 inches.

Carbon steel is commonly used due to its strength and cost-effectiveness, but it requires a greater thickness to ensure it can withstand high temperatures and potential corrosion from heat and grease. Stainless steel, on the other hand, offers superior corrosion resistance and often a lower thickness is acceptable because of its enhanced material properties. This combination of materials and their respective thicknesses ensures that the exhaust fan housing can operate effectively in a commercial kitchen environment where high-temperature conditions and grease-laden vapors are prevalent.

The other options provided do not meet the specifications as outlined in NFPA 96. They either offer incorrect combinations of materials and thicknesses or do not meet the minimum thickness required for the specific applications of exhaust fan housings. Thus, the correct answer meets the NFPA 96 standards ensuring safety and compliance in fire protection measures within commercial cooking facilities.