Linings should be constructed of sheets with a maximum length of how many feet?

The maximum length of lining sheets being specified as 10 feet is based on standard practices in HVAC installations. This limitation helps to ensure ease of handling and installation, as longer sheets can become cumbersome and difficult to work with in tight spaces often encountered in HVAC systems. Additionally, shorter sections reduce the potential for warping or deformation that might occur if longer lengths are used, especially in various working environments.

Having a 10-foot cut-off allows for easier transport and manipulation of sheet metal, and it helps maintain quality and structural integrity as the sheets are installed within ductwork systems. This length is commonly used to balance efficiency and practicality in the installation process, while also ensuring that professionals can adhere to industry standards regarding safety and performance.