What is the maximum allowed length for a horizontal run of a single-wall connector?

The maximum allowed length for a horizontal run of a single-wall connector is specified to ensure proper draft and safety in venting systems. A single-wall connector's maximum horizontal length is set at 75% of the height of the chimney to provide enough upward draft and reduce the risk of condensation build-up, which can occur if the horizontal run is too long.

When the horizontal run exceeds this limit, it can lead to inefficiencies in how gases are vented from the appliance to the outside, potentially creating backdrafts or insufficient venting. Maintaining this ratio supports safe operation and compliance with the North Carolina Mechanical Code, which aims to prevent hazardous conditions like flue gas leaks. Thus, 75% of the chimney height is the proper guideline for ensuring effective and safe venting of heating appliances.