How far must a door swing be from an air inlet or outlet of a vented wall furnace?

The required distance for a door swing from an air inlet or outlet of a vented wall furnace is important for safety and operational efficiency. According to the North Carolina Mechanical Code, a minimum separation of 12 inches is required to prevent any interference with the airflow around the furnace. This distance ensures that the furnace can operate without obstruction, allowing proper ventilation and preventing the possibility of fumes or combustion gases from entering living spaces.

A gap of 12 inches allows enough room for doors to open fully without blocking the air inlet or outlet, which is crucial for maintaining a safe environment. Such a distance minimizes the risk of gas recirculation or improper venting, which can lead to hazardous conditions.

The other distances mentioned, while they may seem reasonable, do not align with the specific requirements outlined in the code for this application. Maintaining the prescribed distance helps ensure that the heating system functions safely and effectively.