What is the minimum slope required for underground ducts to allow for drainage?

The minimum slope required for underground ducts to ensure proper drainage is 1/8 inch per foot. This slope is critical because it helps prevent the accumulation of water or condensate within the ducts, which can lead to various issues, such as corrosion or microbial growth.

The design principle behind this requirement is to facilitate effective drainage through gravitational flow. A slope of 1/8 inch per foot is adequate to direct any moisture away from the duct systems, ensuring they remain functional and efficient over time. This minimal sloping angle strikes a balance, providing enough gradient to promote drainage without compromising the structural integrity or function of the duct.

Understanding this standard can help ensure the longevity and reliability of duct systems in various applications, particularly in environments where water accumulation presents a significant risk.