What is the standard minimum requirement for clearance of ducts to combustible materials?

The standard minimum requirement for clearance of ducts to combustible materials is 6 inches. This specification is crucial for ensuring safety and preventing the risk of fire hazards associated with heating, ventilation, and air conditioning systems. When ducts carry heated air or exhaust, they can elevate temperatures significantly, and maintaining this clearance helps to avoid any potential ignition of surrounding combustible materials.

Having a clearance of 6 inches creates a buffer zone that reduces the likelihood of heat transfer to combustible surfaces, which is a vital aspect of fire safety in building design. This requirement aligns with the standards outlined in the North Carolina Mechanical Code, which emphasizes the importance of proper installation and adherence to clearances to protect both structural integrity and occupant safety.