For grease hood exhaust duct systems less than 75 feet, what is the minimum slope required?

For grease hood exhaust duct systems that are less than 75 feet in length, the requirement for a minimum slope of 1/4 unit vertical is essential to ensure proper drainage and to prevent the accumulation of grease. This slope allows any grease-laden vapors or condensation to flow towards the designated drainage points, reducing the risk of fire hazards and maintaining a clean and efficient exhaust system.

A slope of 1/4 unit vertical strikes a balance that is generally found to be effective for adequately promoting drainage without being too steep, which could lead to other issues such as excessive noise or turbulence within the ductwork. Maintaining this slope is critical for the safe operation of the exhaust system in commercial kitchens, where grease buildup can pose significant safety risks.

Understanding the importance of slope in duct design is crucial for ensuring compliance with mechanical codes and for the overall performance of grease hood exhaust systems.